941 resultados para context-free language


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Malgré la préoccupation croissante des chercheurs et praticiens pour la santé psychologique au travail, le concept de bien-être vécu au travail est encore mal compris de la communauté scientifique. En effet, peu d’efforts ont été consacrés à ce jour pour développer des connaissances sur le bien-être psychologique au travail arrimées à la réalité des employés. Cette thèse a donc pour objectif de développer une conceptualisation du bien-être psychologique au travail et une instrumentation psychométriquement fiable lui étant rattachée. Pour ce faire, deux études ont été réalisées. La première, de nature qualitative et exploratoire, fut menée auprès de 20 travailleurs canadiens francophones afin de répertorier, à partir d’incidents critiques vécus par ceux-ci, des manifestations de bien-être psychologique au travail. Celles-ci ont pu être classifiées selon un modèle en 2 axes, soit la sphère de référence dans laquelle le bien-être psychologique au travail se vit et la directionnalité selon laquelle il se développe. Ce modèle a ensuite été comparé aux conceptualisations génériques du bien-être psychologique existantes, et cette analyse a permis d’étayer la validité convergente et divergente du modèle. Dans un deuxième temps, l’Indice de bien-être psychologique au travail (IBEPT) a été créé sur la base des manifestations relevées lors de l’étude qualitative, afin d’en assurer la validité de contenu. Une version expérimentale de l’instrument a ensuite été soumise à une expérimentation auprès de 1080 travailleurs québécois. Les analyses factorielles exploratoires révèlent une structure interne en 25 items reflétant 5 dimensions, représentant elles-mêmes un construit de second ordre. La validité de construit de cette conceptualisation a ensuite été étudiée par l’analyse des intercorrélations avec une série de mesures du bien-être et de la détresse psychologique génériques. Les résultats appuient la validité convergente de l’instrument, et démontrent également sa validité divergente. Enfin, l’instrument affiche une cohérence interne satisfaisante. Au terme de cette recherche doctorale, les résultats des deux études sont interprétés en fonction de l’état actuel des connaissances sur le bien-être psychologique, les limites des études sont énoncées, et des pistes de recherche future sont avancées.

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Dans un premier temps, nous avons modélisé la structure d’une famille d’ARN avec une grammaire de graphes afin d’identifier les séquences qui en font partie. Plusieurs autres méthodes de modélisation ont été développées, telles que des grammaires stochastiques hors-contexte, des modèles de covariance, des profils de structures secondaires et des réseaux de contraintes. Ces méthodes de modélisation se basent sur la structure secondaire classique comparativement à nos grammaires de graphes qui se basent sur les motifs cycliques de nucléotides. Pour exemplifier notre modèle, nous avons utilisé la boucle E du ribosome qui contient le motif Sarcin-Ricin qui a été largement étudié depuis sa découverte par cristallographie aux rayons X au début des années 90. Nous avons construit une grammaire de graphes pour la structure du motif Sarcin-Ricin et avons dérivé toutes les séquences qui peuvent s’y replier. La pertinence biologique de ces séquences a été confirmée par une comparaison des séquences d’un alignement de plus de 800 séquences ribosomiques bactériennes. Cette comparaison a soulevée des alignements alternatifs pour quelques unes des séquences que nous avons supportés par des prédictions de structures secondaires et tertiaires. Les motifs cycliques de nucléotides ont été observés par les membres de notre laboratoire dans l'ARN dont la structure tertiaire a été résolue expérimentalement. Une étude des séquences et des structures tertiaires de chaque cycle composant la structure du Sarcin-Ricin a révélé que l'espace des séquences dépend grandement des interactions entre tous les nucléotides à proximité dans l’espace tridimensionnel, c’est-à-dire pas uniquement entre deux paires de bases adjacentes. Le nombre de séquences générées par la grammaire de graphes est plus petit que ceux des méthodes basées sur la structure secondaire classique. Cela suggère l’importance du contexte pour la relation entre la séquence et la structure, d’où l’utilisation d’une grammaire de graphes contextuelle plus expressive que les grammaires hors-contexte. Les grammaires de graphes que nous avons développées ne tiennent compte que de la structure tertiaire et négligent les interactions de groupes chimiques spécifiques avec des éléments extra-moléculaires, comme d’autres macromolécules ou ligands. Dans un deuxième temps et pour tenir compte de ces interactions, nous avons développé un modèle qui tient compte de la position des groupes chimiques à la surface des structures tertiaires. L’hypothèse étant que les groupes chimiques à des positions conservées dans des séquences prédéterminées actives, qui sont déplacés dans des séquences inactives pour une fonction précise, ont de plus grandes chances d’être impliqués dans des interactions avec des facteurs. En poursuivant avec l’exemple de la boucle E, nous avons cherché les groupes de cette boucle qui pourraient être impliqués dans des interactions avec des facteurs d'élongation. Une fois les groupes identifiés, on peut prédire par modélisation tridimensionnelle les séquences qui positionnent correctement ces groupes dans leurs structures tertiaires. Il existe quelques modèles pour adresser ce problème, telles que des descripteurs de molécules, des matrices d’adjacences de nucléotides et ceux basé sur la thermodynamique. Cependant, tous ces modèles utilisent une représentation trop simplifiée de la structure d’ARN, ce qui limite leur applicabilité. Nous avons appliqué notre modèle sur les structures tertiaires d’un ensemble de variants d’une séquence d’une instance du Sarcin-Ricin d’un ribosome bactérien. L’équipe de Wool à l’université de Chicago a déjà étudié cette instance expérimentalement en testant la viabilité de 12 variants. Ils ont déterminé 4 variants viables et 8 létaux. Nous avons utilisé cet ensemble de 12 séquences pour l’entraînement de notre modèle et nous avons déterminé un ensemble de propriétés essentielles à leur fonction biologique. Pour chaque variant de l’ensemble d’entraînement nous avons construit des modèles de structures tertiaires. Nous avons ensuite mesuré les charges partielles des atomes exposés sur la surface et encodé cette information dans des vecteurs. Nous avons utilisé l’analyse des composantes principales pour transformer les vecteurs en un ensemble de variables non corrélées, qu’on appelle les composantes principales. En utilisant la distance Euclidienne pondérée et l’algorithme du plus proche voisin, nous avons appliqué la technique du « Leave-One-Out Cross-Validation » pour choisir les meilleurs paramètres pour prédire l’activité d’une nouvelle séquence en la faisant correspondre à ces composantes principales. Finalement, nous avons confirmé le pouvoir prédictif du modèle à l’aide d’un nouvel ensemble de 8 variants dont la viabilité à été vérifiée expérimentalement dans notre laboratoire. En conclusion, les grammaires de graphes permettent de modéliser la relation entre la séquence et la structure d’un élément structural d’ARN, comme la boucle E contenant le motif Sarcin-Ricin du ribosome. Les applications vont de la correction à l’aide à l'alignement de séquences jusqu’au design de séquences ayant une structure prédéterminée. Nous avons également développé un modèle pour tenir compte des interactions spécifiques liées à une fonction biologique donnée, soit avec des facteurs environnants. Notre modèle est basé sur la conservation de l'exposition des groupes chimiques qui sont impliqués dans ces interactions. Ce modèle nous a permis de prédire l’activité biologique d’un ensemble de variants de la boucle E du ribosome qui se lie à des facteurs d'élongation.

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The restarting automaton is a restricted model of computation that was introduced by Jancar et al. to model the so-called analysis by reduction, which is a technique used in linguistics to analyze sentences of natural languages. The most general models of restarting automata make use of auxiliary symbols in their rewrite operations, although this ability does not directly correspond to any aspect of the analysis by reduction. Here we put restrictions on the way in which restarting automata use auxiliary symbols, and we investigate the influence of these restrictions on their expressive power. In fact, we consider two types of restrictions. First, we consider the number of auxiliary symbols in the tape alphabet of a restarting automaton as a measure of its descriptional complexity. Secondly, we consider the number of occurrences of auxiliary symbols on the tape as a dynamic complexity measure. We establish some lower and upper bounds with respect to these complexity measures concerning the ability of restarting automata to recognize the (deterministic) context-free languages and some of their subclasses.

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Examples of compositional data. The simplex, a suitable sample space for compositional data and Aitchison's geometry. R, a free language and environment for statistical computing and graphics

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The Stochastic Diffusion Search (SDS) was developed as a solution to the best-fit search problem. Thus, as a special case it is capable of solving the transform invariant pattern recognition problem. SDS is efficient and, although inherently probabilistic, produces very reliable solutions in widely ranging search conditions. However, to date a systematic formal investigation of its properties has not been carried out. This thesis addresses this problem. The thesis reports results pertaining to the global convergence of SDS as well as characterising its time complexity. However, the main emphasis of the work, reports on the resource allocation aspect of the Stochastic Diffusion Search operations. The thesis introduces a novel model of the algorithm, generalising an Ehrenfest Urn Model from statistical physics. This approach makes it possible to obtain a thorough characterisation of the response of the algorithm in terms of the parameters describing the search conditions in case of a unique best-fit pattern in the search space. This model is further generalised in order to account for different search conditions: two solutions in the search space and search for a unique solution in a noisy search space. Also an approximate solution in the case of two alternative solutions is proposed and compared with predictions of the extended Ehrenfest Urn model. The analysis performed enabled a quantitative characterisation of the Stochastic Diffusion Search in terms of exploration and exploitation of the search space. It appeared that SDS is biased towards the latter mode of operation. This novel perspective on the Stochastic Diffusion Search lead to an investigation of extensions of the standard SDS, which would strike a different balance between these two modes of search space processing. Thus, two novel algorithms were derived from the standard Stochastic Diffusion Search, ‘context-free’ and ‘context-sensitive’ SDS, and their properties were analysed with respect to resource allocation. It appeared that they shared some of the desired features of their predecessor but also possessed some properties not present in the classic SDS. The theory developed in the thesis was illustrated throughout with carefully chosen simulations of a best-fit search for a string pattern, a simple but representative domain, enabling careful control of search conditions.

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The purpose of this study is to explore the strategies and attitudes of students towards translation in the context of language learning. The informants come from two different classes at an Upper Secondary vocational program. The study was born from the backdrop of discussions among some English teachers representing different theories on translation and language learning, meeting students endeavoring in language learning beyond the confinement of the classroom and personal experiences of translation in language learning. The curriculum and course plan for English at the vocational program emphasize two things of particular interest to our study; integration of the program outcomes and vocational language into the English course - so called meshed learning – and student awareness of their own learning processes. A background is presented of different contrasting methods in translation and language learning that is relevant to our discussion. However, focus is given to contemporary research on reforms within the Comparative Theory, as expressed in Translation in Language and Teaching (TILT), Contrastive Analysis and “The Third Space”. The results of the students’ reflections are presented as attempts to translate two different texts; one lyric and one technical vocational text. The results show a pragmatic attitude among the students toward tools like dictionaries or Google Translate, but also a critical awareness about their use and limits. They appear to prefer the use of first language to the target language when discussing the correct translation as they sought accuracy over meaning. Translation for them was a natural and problem-solving event worth a rightful place in language teaching.

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In this paper the architecture of an experimental multiparadigmatic programming environment is sketched, showing how its parts combine together with application modules in order to perform the integration of program modules written in different programming languages and paradigms. Adaptive automata are special self-modifying formal state machines used as a design and implementation tool in the representation of complex systems. Adaptive automata have been proven to have the same formal power as Turing Machines. Therefore, at least in theory, arbitrarily complex systems may be modeled with adaptive automata. The present work briefly introduces such formal tool and presents case studies showing how to use them in two very different situations: the first one, in the name management module of a multi-paradigmatic and multi-language programming environment, and the second one, in an application program implementing an adaptive automaton that accepts a context-sensitive language.

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This research aims at investigating the constructions with adverbials in ly, based on the view of contemporaneous linguistic functionalism, such as proposed by Givón, Hopper, Thompson, Traugott, Furtado da Cunha, as well as the cognitivist notion of language, through construction grammar support upon the patterns of Goldberg and the prototypes theory. The cognitive functional approach adopted here considers the change as a proper and inherent phenomenon of language and understands the linguistic phenomenon as resulting from effective use of language. Another aspect to be considered to the realization of this study is the fact that the formation adjective + ly is a word construction mechanism really productive, which generates interests on linguistic description. In a particular way, our leading objective is to exam the constructions with adverbials in ly in the context of language in use, in its oral and written forms, looking for to apprehend the meaning multiple manifestations forged in the use. Bearing this in mind, we worked with data from the Corpus Discurso & Gramática (Natal). There are, in the data, adverbs ended in ly that take the signification of mode, as foreseen in traditional models, but there are also other significations, for instance, the modalizador in its different manifestations. The results show that this adverb is a linguistic mark that carries in its constitution the multissêmico and multifunctional character, which interferes extremely in the ordination of this category, assuming a position sometimes pre-verbal, sometimes post-verbal. Other aspect observed refers to the relationship between the adverb and the verb, with emphasis on the compatibility or restriction between them, option which is related to the semantic aspect. The data in analysis legitimate the use in different constructions with adverb ended in ly in various genres, as follows: personal experience narrative, retold narrative, local description, proceeding account, opinion account, both in oral as in written language

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This study is part of interactional perspective, focusing on Conversation Analysis theories, from the Textual Interactive Perspective and Text Linguistics . This research, from its guiding questions, aims at understanding the interaction between teacher and students in the process of the knowledge construction as well as at describing, analyzing and understanding aspects of topical organization speech in the classroom in elementary school, observing the opening and closing procedures of the speech topics in that particular space. Considering that the procedures for opening and closing of discursive topics occur through language marks, we tried to identify which speech marks are used in the opening and closing of the topics studied in the classroom, in interaction during the collaborative process of the discourse established between teacher and students. Therefore, this study is based on authors who analyze specific questions of the text in real context of language use: Koch (1993, 1999), Jubran et al (1991), Jubran (2006), Pine (2005), Penhavel (2010), Galembeck (2012), Barros (1991), Marcuschi (1986 , 1990, 1991 , 1998 , 1999, 2003 , 2004a), Kerbrat - Orecchioni (2006), Favero (1999, 2002) and Galvão (2004, 2010). As a methodology of investigation, the study is focused on the postulates of ethnographic research in order to carry out data collection, through audio and video recordings which were transcribed, according to the NURC project proposal, with some adaptations. Data analysis showed that the procedures for opening and closing of the speech topics occurred by the use of discourse markers, in particular the marker "then", allowing us to understand that these elements are important in the topical organization speech, contributing to ensure textual cohesion and coherence. We conclude that the organization of the discursive topic in the classroom occurs through events that support the explicitness of the content of teaching and learning, considering the diverse necessity of an institutional academic plan, whose main objective is the construction of knowledge

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The approach Software Product Line (SPL) has become very promising these days, since it allows the production of customized systems on large scale through product families. For the modeling of these families the Features Model is being widely used, however, it is a model that has low level of detail and not may be sufficient to guide the development team of LPS. Thus, it is recommended add the Features Model to other models representing the system from other perspectives. The goals model PL-AOVgraph can assume this role complementary to the Features Model, since it has a to context oriented language of LPS's, which allows the requirements modeling in detail and identification of crosscutting concerns that may arise as result of variability. In order to insert PL-AOVgraph in development of LPS's, this paper proposes a bi-directional mapping between PL-AOVgraph and Features Model, which will be automated by tool ReqSys-MDD. This tool uses the approach of Model-Driven Development (MDD), which allows the construction of systems from high level models through successive transformations. This enables the integration of ReqSys-MDD with other tools MDD that use their output models as input to other transformations. So it is possible keep consistency among the models involved, avoiding loss of informations on transitions between stages of development

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The work proposed by Cleverton Hentz (2010) presented an approach to define tests from the formal description of a program s input. Since some programs, such as compilers, may have their inputs formalized through grammars, it is common to use context-free grammars to specify the set of its valid entries. In the original work the author developed a tool that automatically generates tests for compilers. In the present work we identify types of problems in various areas where grammars are used to describe them , for example, to specify software configurations, which are potential situations to use LGen. In addition, we conducted case studies with grammars of different domains and from these studies it was possible to evaluate the behavior and performance of LGen during the generation of sentences, evaluating aspects such as execution time, number of generated sentences and satisfaction of coverage criteria available in LGen

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This paper is a qualitative ethnographic study that aims to present reflections on negotiation events in teletandem interactions, a synchronous telecollaborative context of language learning, within the scope of the interaction strategies adopted by participants to achieve comprehensibility. The project Teletandem Brasil: foreign languages for all (Telles, 2006) matches up native or proficient speakers of a foreign language with Brazilian undergraduate students to learn each other's language, by communicating synchronically with application softwares like Skype, Oovoo or MSN. on this paper, based on the interpretive perspective of Hermeneutics, we analyze excerpts of teletandem interactions of partnerships established between students of a Brazilian university and American universities. The excerpts presented here have been taken from different moments of the research studies conducted at the teletandem laboratories of UNESP Assis and Sao Jose do Rio Preto and are part of the database of the works of Santos (2008) and Garcia (2010). In this article, in the data analysis, we highlight the focus on form and on lexicon as characteristics of the interactions and analyze how the negotiations happen in this learning context mediated by technology. Among results we may highlight the prevailing of external feedback as a trigger to negotiation moves, the occurrence of adjustment processes between participants to get adapted to each other's interaction behavior, as well as the evolution of this behavior as interactants get familiarized with the computer-mediated communication context, under the shape of changes in the participants choices regarding negotiation of meaning along their interaction experience.

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Pós-graduação em Educação - FFC

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This study aimed to enter a training program for family members of children, youth and adults who use augmentative and alternative communication systems in the context of alternative languages . The study included families in the age group of 25-65 years in the period 2010- 2012. The activities were held weekly with duration of one hour in a alternative communication laboratory. All activities were videotaped and after that, the verbal participants’ reports were transcribed. The obtained categories were analyzed according to the steps of the program. The results indicated that families realized: the necessity of graphics systems for communication; the importance of adapted materials; and the need to understand their children’s different skills. The study reinforced the need for systematic and continuous guidance for families, as well as highlighted the use of graphics systems in the context of language.

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This article aims to show the results of an institutional research in Applied Linguistics, which tries to comprehend how the initial teaching practice occurs in diversely figured contexts of foreign language teaching-learning (on-site and virtual), as well as how such contexts may mutually favor and encourage reflective and critical training of the language teacher in/for a contemporary world. It´s possible to notice a reflective attitude of four Brazilian foreign language (Spanish, English and Italian) teachers in initial training, especially regarding some aspects related to the teaching-learning languages process, such as roles of the participants; relevance of meaningful interaction; engaged cultures; teaching of a foreign language and mother tongue teaching as foreign one; teaching and learning typologically similar languages; constitution of the place to learn-teachIt´s possible to notice a reflective attitude of four Brazilian foreign language (English, Italian and Spanish) teachers in pre-service education, especially about some aspects of language teaching and learning process, such as the role of the participants; the relevance of significant interactions; the involved cultures; the teaching of a foreign language and the teaching of the mother tongue as a foreign language; the teaching of similar languages as Portuguese and Spanish; and the constitution of the place of teaching and learning languages. The results indicate that the experience of experiencing the dynamics of a conventional didactic context of language teaching (classroom), alongside to the experience of teaching and learning in a context of virtual educational settings (teletandem), it was especially important for the critical training of the future language teachers and to the awareness about the practice of teaching languages in times of technological innovation.