L’objectif de ce travail vise, à partir d’un modèle mésoscopique basé sur les automates cellulaires, qui prend en compte un petit nombre de processus simples, à interpréter les simulations numériques obtenues afin de mieux appréhender la complexité de la corrosion. Dans la première partie de ce mémoire, le modèle est appliqué à deux cas : un métal protégé par une couche isolante présentant un défaut et un métal recouvert d’une couche d’oxyde. Les réactions anodiques et cathodiques simulées peuvent se faire soit sur un même site (réactions localisées) soit sur deux sites différents (réactions spatialement séparées). L’étude des réactions localisées montre le détachement d’îlots métalliques au cours de la corrosion. Ces résultats correspondent à un phénomène mis en évidence expérimentalement l’effet chunk, responsable de déviations à la loi de Faraday. Il est montré que la vitesse effective de corrosion est amplifiée par la production des îlots résultant d’un couplage corrosion-érosion. Les réactions anodiques et cathodiques spatialement séparées sont ensuite étudiées montrant l’influence de la diffusion des espèces acido-basiques dans l’électrolyte et mettant en évidence, un régime initial où la solution reste homogène, suivi d’un régime limité par la diffusion où apparaissent des hétérogénéités chimiques engendrant des hétérogénéités physiques (rugosité du front). Le couplage entre les phénomènes chimiques et morphologiques est clairement démontré. Enfin dans une dernière partie, nous nous sommes attachés à mettre en évidence expérimentalement les déviations à la loi de Faraday dans le cas de la corrosion du zinc en milieu acide sulfurique. / The aim of this study is, using a mesoscopic model based on cellular automata and taking into account a small number of simple processes, to explain numerical simulations obtained in order to better understand the complexity of corrosion. In the first part of this work, the model is used to simulate corrosion in a defect of material protected by an insulating layer and on a metal covered by an oxide layer. Anodic and cathodic reactions simulated in the model can take place in the same site (localized reactions) or in two different (spatially separated reactions) sites. Study of localized reactions shows the detachment of metallic islands during corrosion. These results correspond to a phenomenon which has been experimentally proven, named chunk effect, and is responsible of the deviation with Faraday’s law. It is shown that effective corrosion speed is enhanced by the production of islands resulting from corrosion-erosion coupling. Secondly studies of spatially separated reactions, have shown the influence of the diffusion of acid-basic species in the solution and have permitted to carry out, an initial regime characterised by an homogenous solution, followed by diffusion limited regime, where chemical heterogeneities leading to physical heterogeneities (roughness of the front) appear. The relationship between chemical and morphological phenomena is clearly demonstrated. Finally we have demonstrated experimental deviations with Faraday’s law in the case of zinc corrosion, in sulphuric acid medium.

SCTP (Stream Control Transmission Protocol) was proposed by IETF. It shows superior extensibility and compatibility as compared to other transport layer protocols, such as TCP and UDP. In addition, it supports multi-streaming and multi-homing. Although an SCTP connection can convey many video streams from different applications, it lacks the provision of different QoS for different streams in the same association. On the other hand, more and more mobile devices are equipped with multiple network (e.g., UMTS/WLAN) interfaces to transmit packets over 3G cellular networks or wireless local area networks. This thesis presents a dynamic chunk adjustment scheme for SCTP-based video streaming in an integrated UMTS and WLAN network. The proposed scheme can support QoS guarantees for different streams in an SCTP association whenever a mobile node moves across the two networks or remains service by either network. Besides, when a mobile node roams from a WLAN to a UMTS, the proposed ¡§deassociation¡¨ capability is applied to increase the channel utilization in 3G cellular networks. Performance evaluations on NS-2 are presented to demonstrate the effectiveness and the advantage of our proposed scheme over the original SCTP.

<p>The increasing complexity of Information Systems (IS) calls for IS development methods to be adapted to the specific situations of the projects at hand. Method engineering is important because it focus on the creation of new methods that can be used in the system development process with the aim of constructing new information systems. The size and complexity of projects for developing information systems are becoming larger and more complicated. Therefore, development methods turn out to be one of the most significant key factors to achieve great success of development projects.</p><p>The discipline of Situational Method Engineering (SME) focuses on the creation of new project specific methods. SME is a reuse strategy to assemble reusable method fragments or method chunks originating from different methods. New methods can be constructed from a method repository by selecting the chunks that are the most appropriate to a given situation. Thus, method chunks are the basic building blocks for constructing methods in a modular way.</p><p>This dissertation have identified, analyzed and categorized a set of interoperability problems for the content of a method chunk repository. These problems have been represented as a set of patterns. The patterns will facilitate the understanding of specific interoperability problems that belong to a specific method chunk. If we are aware of the different interoperability problems that exist it is more likely that we can use a method chunk successfully within the context of SME.</p>

Nous proposons un modèle de vérification grammaticale automatique gauche-droite issu de l'analyse d'un corpus d'erreurs tapuscrites. Les travaux menés en psychologie cognitive ont montré que le processus de révision procède au travers de la confrontation d'une attente à un résultat. Ainsi, la détection d'une erreur grammaticale reposerait, chez l'humain, sur une attente du réviseur non comblée. Ce principe est à la base du modèle que nous avons élaboré. Pour faciliter la gestion des attentes du point de vue traitement numérique, nous convions deux concepts courants en TAL : le principe d'unification et la segmentation en chunks. Le premier est particulièrement adapté à la vérification des accords et le second constitue une unité de calcul intermédiaire permettant de définir des bornes simplifiant la recherche d'incohérences grammaticales. Enfin, l'originalité de ce modèle réside dans une analyse gauche-droite construite au fur et à mesure de la lecture/écriture. / This thesis presents a model for automated left-right grammar checking based on analysis of a corpus of typescript errors. Studies in cognitive psychology have shown that the revision process works by confronting expectations with results. For humans, detecting a grammatical error therefore relies on an unfulfilled expectation on the part of the revisor. The model presented here is based on this principle. In order to deal with expectations from the point of view of computational processing, two common concepts in NLP are called upon: the unification principle and chunk segmentation. The former is particularly adapted to checking agreements, while the latter provides an intermediate computational unit to delimit, and therefore simplify, detection of grammatical inconsistencies. Finally, the model?s originality lies in the left-right analysis it provides, which is constructed as the text is produced/read.

The increasing complexity of Information Systems (IS) calls for IS development methods to be adapted to the specific situations of the projects at hand. Method engineering is important because it focus on the creation of new methods that can be used in the system development process with the aim of constructing new information systems. The size and complexity of projects for developing information systems are becoming larger and more complicated. Therefore, development methods turn out to be one of the most significant key factors to achieve great success of development projects. The discipline of Situational Method Engineering (SME) focuses on the creation of new project specific methods. SME is a reuse strategy to assemble reusable method fragments or method chunks originating from different methods. New methods can be constructed from a method repository by selecting the chunks that are the most appropriate to a given situation. Thus, method chunks are the basic building blocks for constructing methods in a modular way. This dissertation have identified, analyzed and categorized a set of interoperability problems for the content of a method chunk repository. These problems have been represented as a set of patterns. The patterns will facilitate the understanding of specific interoperability problems that belong to a specific method chunk. If we are aware of the different interoperability problems that exist it is more likely that we can use a method chunk successfully within the context of SME.

¡@¡@In this Thesis, we proposed a new SVC Layer Scheduling Algorithm (CSDB, Chunk Scheduling with Delay-trend and Bandwidth-monitoring) in SVC-P2P Video Streaming by using RTT Probing and Bandwidth Monitoring mechanisms to measure RTT/2 and historic bandwidth between peers simultaneously. When transmission delay (TD) dominates in the end-to-end delay and when instantaneous bandwidth increases, peer will quickly increase the downloading layers of video segment (VS). On the other hand, when instantaneous bandwidth decreases, peer will decrease the number of layer chunks (LCs) not in time according to RTT/2 and historic bandwidth. When queuing delay (QD) and propagation delay (PD) dominate in the end-to-end delay, peer will assume RTT/2 is accurate because every LC is in time. In this case, peer will quickly increase the downloading layers; otherwise, peer assumes there is a big difference between RTT/2 and one-way delay (OWD) such that it will decrease the downloading layers to half. When peer cannot grab VS in time according to measured RTT/2 but every LC grabbed is in time, peer will assume there is a big difference between measured RTT/2 and OWD. In this case, peer will keep no change in downloading layers; otherwise, peer will assume measured RTT/2 is close to OWD, and it will decrease the downloading layers to half. ¡@¡@In order to demonstrate the advantages of CSDB, we designed a simulator written in C++. In the simulation, we consider two scenarios: 1) When TD dominates. 2) When QD and PD dominate. Simulation results show that peer can achieve high quality SVC video by balancing the number of received layers and the number of LCs not it time.

Étudier la liaison et les erreurs enfantines qu’elle entraîne (le nami, un zami) offre une perspective privilégiée sur le développement des représentations lexicales. Des travaux récents (Chevrot, et al., 2007 ; Dugua et al., 2009 ; Chevrot et al., à paraître) ont corroboré un modèle (Chevrot et al., 2009) rendant compte des étapes développementales jalonnant la segmentation des noms précédés d’une liaison. Nous avons mis en place, durant ce doctorat, trois démarches empiriques examinant des hypothèses issues de ce modèle.L’observation de 18094 groupes nominaux déterminant-nom issus d’un corpus de 118 heures de parole adressée à cinq enfants entre 1 et 3 ans fait apparaître trois tendances : 86% contiennent un nom à initiale consonantique (un garçon), la liaison (un ami) n’apparaît que dans 5% des GN, les consonnes enchainées sur l’initiale vocalique des noms sont principalement les liaisons /n/, /z/, /t/ ou le /l/ de l’élision (l’ami). La rareté des liaisons est compatible avec la complexité de leur acquisition. La prévalence des noms à initiale consonantique dans l’input est compatible avec la tendance enfantine à faire correspondre l’initiale du nom avec une consonne et ainsi à produire des segmentations de type /zami/, /nami/ ou /lami/ pour le mot ami. Cette étude aura permis de confirmer une hypothèse sur trois du modèle.Une expérience chronométrique menée chez 60 enfants de 5-6 ans montre que ces derniers ont mémorisé dans leur lexique aussi bien des variantes de type /nami/ et /zarbr/ pour les noms ami et arbre que des séquences fréquentes contenant ces variantes (un-ami, des-arbres). La même étude chez 36 adultes indique ceux-ci mémorisent dans leur lexique des séquences entières, sans retrouver de traces des variantes.Enfin, nous avons exploré l'hypothèse de Morin & Kaye (1982) qui suggéraient un statut particulier à la liaison /z/ : en effet, elle semble pouvoir être inscrite dans notre lexique comme un morphème du pluriel. De ce fait, elle bénéficierait d'un encodage encore plus abstrait, au niveau morphologique.Ces résultats sont discutés dans la perspective des théories basée sur l’usage (Tomasello, 2003) postulant un lexique constitué d’unités de longueurs et de niveaux d’abstraction variables. / Studying the liaison in French and childish mistakes it entails (un nami, un zami) offers a unique perspective on the formation of lexical representations. Recent work (Chevrot and al., 2007; Dugua and al, 2009;.. Chevrot and al, forthcoming) corroborated a model (Chevrot et al., 2009) reflecting the developmental stages during which segmentation of nouns that are preceded by a liaison. We have implemented during this PhD, three empirical approaches to examine the hypotheses which emerge from this model.Observing 18094 déterminant-noun groups from a corpus of 118 hours of speech addressed to five children between 1 and 3 years reveals three trends: 86% contain a noun with an initial consonant (un garçon), the liaison (un ami) appears only in 5% of NG's [for "Noun-Groups"], the consonants which are attached to the initial vowel of nouns are mainly the liaisons / n /, / z /, / t / or the elision / l / (l’ami). The scarcity of the liaison is consistent with the complexity of acquiring it. The prevalence of nouuns with an initial consonant in the input is compatible with children's tendency to match the initial of the name with a consonant and thus to produce segmentations like / zami /, / nami / or / lami / for the word ami. This study has confirmed one of the three hypothesis of the model.A chronometer experiment on 60 5-6 years old children shows that they have stored in their lexicon as well variants like / nami / and / zarbr / for nouns ami and arbre, as frequent sequences containing these variants (un-ami, des-arbres). The same study on 36 adults indicatesthat they store in their lexicon entire sequences, without finding any trace of these variants.Finally, we explored the hypothesis of Morin & Kaye (1982)which suggested that the liaison / z / had a special status : indeed, it seems to be written in our lexicon as a morpheme of the plural form. Therefore, it would benefit from an even more abstract encoding, morphologically.These results are discussed from the perspective of theories based on the common use (Tomasello, 2003) wich states that lexicon consists of units with varying lengths and levels of abstraction.

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This thesis investigates materialization and representation in contemporary architectural design practice. Due to cultural and technological shifts, the act of design is no longer squarely located in the abstract realms of drawings or digital geometries. Computer aided manufacturing, simulation and scanning offer new design opportunities that are located in the transfer between representation and material. This has given rise to a post-digital model of practice and thought, in which ‘real’ and discrete chunks of matter are incorporated at the earliest stages of design. The thesis is practice-based, and spans in scope from design to technology to theory. The design work included explores materialization and representation from a particular point of view. In addition, it suggests a methodological approach to design, and explores the theoretical implications in this approach. These implications are addressed in two connected research questions: How can material processes, whether real or simulated, turn transfers between geometry and materialized objects into productive design opportunities? And how might material simulation alter the ways in which representations are conceptualized and used by architects? In parallel with practice-based work, the thesis suggests a theoretical framework for current issues of representation and materialization in architecture. This framework draws from the recent history of the digital turn in architecture as well as from recent design research work and theory in a post-digital turn. This thesis makes contributions in three main areas. Through the design work Erratic, it makes a visceral case for how the use of material simulation might open up new ways of harnessing material agency. It positions simulation in the field of architecture in-between established polarities such as geometry vs. matter, virtual vs. real and drawing vs. mock-up. It discusses the conceptual difference between design based on geometry and design based on discrete pieces of material. Finally, it proposes that form in architecture increasingly can be conceptualized as ‘chunks,’ as opposed to reduced descriptions of geometry. / <p>QC 20161102</p>

Specifications of digital hardware systems are typically written in a natural language. The objective of this research is automatic information extraction from specifications to aid model generation for system level design automation. This is done by automatic extraction of the noun phrases and the verbs from the natural language specification statements. First, the natural language sentences are parsed using a chart parser. Then, a noun phrase and verb extractor scans these charts to obtain the noun phrases with their frequencies of occurrence. The noun phrases are then classified by semantic types. Also the verbs are automatically assigned their respective roots and classified. Finally, each sentence is summarized as a sequence of &quot;chunks&quot;: noun phrases, verbs and prepositions. Vectors are generated from these chunks and imported into MS Excel for plotting occurrence graphs of noun phrases and verbs with respect to the sentences in which they occur. Finally, inter-term dependencies between noun phrases, and between noun phrases and verbs were studied. The frequencies of occurrence, the classification of chunks, the occurrence graphs and the inter-term dependencies together give useful information about the subject, the hardware components and the behavior of a system described by a natural language specification document. / Master of Science