Dissertationen zum Thema „Reference technique“

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 121-125).
The performance of switched-capacitor circuits depends highly on the op-amp specifications. In conventional designs, trade-offs in speed, noise, and settling accuracy make it difficult to implement power-efficient switched-capacitor circuits. The problem originates from the inverse relationship between the feedback factor and the signal gain. This thesis proposes the virtual ground reference buffer technique that enhances performance by improving the feedback factor of the op-amp without affecting signal gain. A key concept in the technique is the bootstrapping action of level-shifting buffers. It exploits op-amp-based circuits whose principles are very well understood and the design techniques are mature. The solution ultimately relaxes the required op-amp requirements including unity-gain bandwidth, noise, offset voltage and open-loop gain that would otherwise result in complex design and high power consumption. The concept is demonstrated in a 12-b 250MS/s pipelined ADC.
by Hyun Ho Boo.
Ph. D.

International Telemetering Conference Proceedings / October 29-November 02, 1990 / Riviera Hotel and Convention Center, Las Vegas, Nevada
This paper describes the technical principle that signals conversion, data-processing and data storage are directly carried out without filling up with the reference pulse for PPM and PPK (pulse position keying). By means of analysis for typical frame structure of PPM/PPK signals, a variety of math models of signal time relationship of the system were found, and based on this, a engineering way and a principle block diagram for signals conversion, data processing and data storage were given out.

The early stages of damage by corrosion fatigue in austenitic and duplex stainless steel were studied using a novel scanning reference electrode technique (SRET). Emphasis was made on the role played by corrosion pits, which can act as stress concentrators and promote fatigue crack nucleation. SRET measurements conducted during the potentiostatic generation of pits on the austenitic stainless steels in artificial seawater showed that the pit current density increases with the time of application of anodic polarisation. The data of the volume of metal dissolved calculated from pit current density obtained by SRET agreed well with the measurements of pit profiles. The austenitic and duplex stainless steels showed high resistance to pitting corrosion in artificial seawater at free corrosion potential. The use of a 0.05 M FeCl3 solution as the electrolyte promoted severe localised attack in 304 and 316L stainless steel specimens. SRET tests carried out simultaneously with the application of cyclic stress to the specimens permitted the evolution of the electrochemical activity of corrosion pits to be followed. Transformation from pitting to fatigue cracking was observed. In this work it is proposed that a decrease of the pit electrochemical activity in terms of pit current density, is related to the nucleation of the corrosion fatigue crack. From SRET measurements a critical pit depth was calculated for the nucleation of the fatigue crack. A threshold stress intensity factor range was then calculated, which was found to be similar to the values reported in the literature. It is suggested at the end of this thesis that parallel studies and measurements of the pit-to-crack transition can be conducted in order to corroborate the reliability of SRET measurements to assess semi-quantitatively the threshold conditions for the transition. The scanning reference electrode technique showed advantages over other electrochemical methods used to assess the damage induced by localised corrosion in that it provides in-situ, spatially resolved, real-time electrochemical activity measurements.

Thesis (M.S.)--West Virginia University, 2002.
Title from document title page. Document formatted into pages; contains vii, 35 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 29-30).

Bibliography: leaves 192-196.
This study analyses Role Play teaching techniques employed in Educational Drama and examines the possibility that the current practice of Role Play may actually obstruct the personal and collective empowerment of students, thereby limiting the educative potential of drama.

Voice training has been influenced by separatist attitudes which have allowed for classes which train the body to be separate from those which train the voice. This study acknowledges that to train an actor in separate compartments and then expect the completeness of human expression in performance, is to train under false pretences. There is a need to address the imbalance of separatism and this is examined within the context of voice training. An holistic approach to voice training forms the basis of the argument, which focuses on the need to re-educate the notion of physicality in voice training. Chapter one proposes an understanding of the notion of physicality by drawing on the attitudes of selected theatre practitioners towards the physical nature of the theatre encounter. The expressive energies of the actor's body are responsible for the physicalisation of a play; for this reason the movement of voice and speech is not only examined as source movement, but also as the movement of an actor's response and communication. Chapter two examines some practices which led to attitudes of separatism in voice training, and introduces prevalent practices which are attempting to involve the energy of the physical experience. Chapter three proposes that the Alexander technique be used as the foundation for an awareness of individual physicality. Where chapter one examines the theory of this notion, chapter three proposes an experiential understanding of the same. The Alexander technique is a training in effective body use and it's principles are fundamental to an awareness of body use and functioning. It is argued that these principles should underlie a re-education of physicality. The final chapter of the thesis argues for physicality in South African voice training programmes which would complement the physicality of contemporary theatre forms. It is hoped that this study will provide further incentive for the continued review and adjustment of drama training in South Africa.

Os referenciais tecnológicos são documentos técnicos de referência, não normativos, elaborados e consensualizados por agentes da cadeia produtiva, visando à disseminação das boas práticas para o processo de produção de edifícios (planejamento, projeto, execução, uso, manutenção e pós-uso), com o intuito de se obter qualidade e adequado desempenho do produto final, bem como de consolidar e difundir o conhecimento no setor. Documentos como esses já são efetivamente utilizados em diversos países, como modelos de códigos de práticas (PRGHO_FRGHV ou FRGHV_RI_SUDFWLFHV) e guias de práticas recomendadas (EHVW_ SUDFWLFH_ JXLGHV); enquanto a construção civil brasileira, apesar de algumas iniciativas, ainda está aquém do desejado nessa área. Assim, o objetivo dessa dissertação é analisar, discutir e propor orientações técnicas, metodológicas e institucionais para a elaboração e implementação de referenciais tecnológicos para o setor de edificações no Brasil. Para tanto, faz-se uma pesquisa e caracterização de documentos nacionais, como cadernos de encargos e manuais técnicos, discutindo a estrutura e o conteúdo dos mesmos e mostrando ainda, por meio de um estudo de caso, a aplicação prática de um documento utilizado em habitações de interesse social no Estado de São Paulo (Manual de Controle de Obras e Serviços). Apresentam-se, ainda, alguns documentos estrangeiros, além de um estudo mais detalhado sobre os documentos técnicos utilizados na França ('RFXPHQWV_7HFKQLTXHV_8QLILpV___'78), discutindo-se a sua adaptação à realidade brasileira. Concluise o trabalho analisando, dentre outros fatores, o conceito de referenciais tecnológicos, seu contexto e interfaces, dando orientações quanto à estrutura e ao conteúdo de documentos desse tipo e citando dificuldades e oportunidades de desenvolvimento e aplicação dos mesmos, bem como a necessidade de ações paralelas, incluindo de natureza institucional, que contribuam para o seu uso prático e efetivo.
The “ technical references” are documents that can be used in different phases of the a building project, with no legal effect as standards or Codes, developed by the agents of the industry, to establish and disseminate best practices for planning, design, execution, use, maintenance and post-use phases, with the aim of to achieve quality and performance of the final product and to consolidate and to broadcast knowledge. Such documents exist in different countries, as the “model codes” or “ codes of practices” and the “ best practice guides” , but this is not the case in Brazil, even though we can find some initiatives in this way. Consequently, the objective of this research is to analyse, discuss and propose technical, methodological and institutional orientations to the implementation of technical referencesfor the building construction sector in Brazil. For this purpose, there is a review of documents such as procurement texts and technical manuals, an analysis of their structures and contents and a deeperexamination of the application of the document used in social housing projects in Sao Paulo. Some foreign documents are also analysed, as well as the technical documents model used in France ('RFXPHQWV_ 7HFKQLTXHV_ 8QLILpV_ __ '78), discussing its adaptation to fit Brazilian reality. The conclusion of this work lies in the analysis, amongst other factors, of the concept of technical reference documents, its context and interfaces, bringing orientation concerning their structure and content, and presenting difficulties and opportunities of developing and using them, as well as showing the need of additional actions, including those of institutional nature, that contribute to their practical and effective use.

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 143-144).
In this work we present a blurred interface method for Fluid-Solid Interactions (FSI) and multiple solids immersed in a fluid or FSSI (Fluid-Solid-Solid Interactions) based on the reference map technique as presented by Kamrin and Rycroft. I will follow the chain of thought which lead from the initial sharp interface technique to the newer blurred interface one. We will present its capabilities of doing fully-coupled simulations of a compressible Navier-Stokes fluid and highly non-linear solid undergoing large deformations all performed on a single Eulerian grid with no Lagrangian particles whatsoever. The Reference Map Technique (RMT) provides an Eulerian simulation framework allowing to compute fully coupled fluid/soft-solid interactions. However, due to the extrapolations inherent to the Ghost Fluid Method (GFM) for fluid/fluid interactions, on which the RMT is based, numerical artifacts get created in the resulting pressure and velocity fields whenever the levelset defining the interface crosses a gridpoint from the fixed cartesian grid utilized in this method. We will therefore follow the creation and propagation of these artifacts as well as analyze how the blurred technique solves or avoids these problems.
by Boris Ivanov Valkov.
S.M.

A part of Johann Sebastian Bach’s musical duties in Leipzig was to present an annual setting of the passion for Good Friday Vespers. One such work was the Markuspassion, performed in 1731. Although the score of this companion work to the Matthäuspassion and Johannespassion has been lost, the original text of the Markuspassion is extant. Bach frequently made use of the parody technique in his compositions. This practice consisted of adapting existing music to a new text that was based on the rhyme scheme of the original one, resulting in two compositions essentially sung to the same music, barring a number of enforced changes. This particular feature of Bach’s compositional technique makes it possible that the lost music originally contained in the Markuspassion could be discovered within his oeuvre. In the late 19th century, Bach scholars began to research the possibility of reconstructing the Mi>Markuspassion, recognizing that it may have contained music parodied from other compositions basing, to a large extent, their research on textual comparison. Several attempts at reconstruction have been made between 1964 and 2009, resulting in at least 18 different versions of the Markuspassion. Some of reconstructors abandon the original structure of this work, others re-use music that Bach could not plausibly have chosen as a parody base for this work, while still others include large amounts of music composed by contemporaries of Bach. This has lead to the question: To what extent are the existing reconstructions of Johann Sebastian Bach’s Markuspassion historically justified, and what sources have reconstructors utilized in order to achieve performable editions? Five of the reconstructions have been carefully studied in this regard, leading to the conclusion that they are all worthwhile scholarly endeavours with their own merits, but that none of them can be performed as the definitive Bach Markuspassion. This study also contains recommendations to musicologists interested in this project, conductors wanting to perform one of these works and suggestions for a theoretical reconstruction combining material from existing attempts.
Dissertation (MMus)--University of Pretoria, 2010.
Music
unrestricted

Les techniques de référence à rang réduit sont couramment employées pour résoudre les problèmes d’extraction de source et de resynchronisation de champs physiques, lorsque le nombre de références dépasse celui des sources incohérentes. Dans ce cas, la matrice croisée-spectrale devient mal conditionnée, rendant la solution des moindres carrés invalide. Bien que la décomposition en valeurs singulières tronquée (DVST) soit utilisée pour résoudre ce problème, elle n'est valable que pour un bruit scalaire sur les références. De plus, il est difficile de définir un seuil de troncature lorsque les valeurs singulières diminuent progressivement. Cette thèse propose une solution nommée technique de référence maximale-coherent (RMC), basée sur la recherche d’un ensemble de références virtuelles maximales correlées avec les mesures de champ. Cette technique est optimale, surtout en présence d’un bruit corrélé sur la référence. Cependant, elle nécessite également une troncature des valeurs propres, exigeant la connaissance ou l’estimation préalable du nombre de sources incohérentes, un problème inverse mal posé et peu étudié. La thèse présente trois méthodes d’énumération de sources applicables à toutes les techniques de référence : un test du rapport de vraisemblance contre le modèle saturé, une technique de bootstrap paramétrique et une approche de validation croisée. Une étude comparative basée sur des données numériques et expérimentales montre deux résultats importants. D'abord, le nombre de fenêtres spectrales utilisées affecte grandement la performance des trois méthodes, qui se comportent différemment selon ce nombre. Ensuite, le bootstrap paramétrique s’avère être la meilleure méthode en termes de précision et de robustesse par rapport au nombre de fenêtres utilisées. Enfin, la technique RMC accompagnée de bootstrap a été utilisée pour l’extraction de source et la resynchronisation de données réelles provenant d’expériences en laboratoire et d’un moteur électrique, fournissant de meilleurs résultats que la solution des moindres carrés et la DVST dans les mêmes conditions
Rank-reduced reference/coherence techniques based on the use of references, i.e. fixed sensors, are widely used to solve the two equivalent problems of source extraction and resynchronization encountered during remote sensing of physical fields, when the number of references surpasses the number of incoherent sources. In such case, the cross-spectral matrix (CSM) becomes ill-conditioned, resulting in the invalidity of the least squares LS solution. Although the truncated singular value decomposition (TSVD) was successfully applied in the literature to solve this problem, its validity is limited only to the case of scalar noise on the references. It is also very difficult to define a threshold, for truncation, when the singular values are gradually decreasing. This thesis proposes a solution based on finding a set of virtual references that is maximally correlated with the field measurements, named the maximally-coherent reference (MCR) Technique. This solution is optimal, especially, in the case of correlated noise on the reference, where TSVD fails. However the technique also includes an eigenvalue truncation step, similar to the one required for the TSVD, which necessitates a priori knowledge or the estimation of the number of incoherent sources, i.e. source enumeration, which is an ill-posed inverse problem, insufficiently investigated in the literature within the framework of reference techniques. In this thesis, after providing a unified formalism for all the reference techniques in the literature, three alternative source enumeration methods, applicable to all the reference techniques, were presented namely; a direct likelihood ratio test (LRT) against the saturated model, a parametric bootstrap technique and a cross-validation approach. A comparative study is performed among the three methods, based on simulated numerical data, real sound experimental data, and real electrical motor data. The results showed two important outcomes. The first is that the number of snapshots (spectral windows), used in the spectral analysis, greatly affects the performance of the three methods, and that, they behave differently for the same number of used snapshots. The second is that parametric bootstrapping turned out to be the best method in terms of both estimation accuracy and robustness with regard to the used number of snapshots. Finally, the MCR technique accompanied with bootstrapping was employed for source extraction and resynchronization of real data from laboratory experiments, and an e-motor, and it returned better results than the LS solution and the TSVD when employed for the same purpose

La détermination de la rugosité sub-nanométrique sur les flancs des motifs, dont les dimensions critiques atteignent une taille inférieure à 10nm, devient une étape primordiale. Mais à ce jour aucune technique de métrologie n'est suffisamment robuste pour garantir un résultat juste et précis. Une voie actuellement en cours d'exploration pour la mesure dimensionnelle consiste à hybrider différentes techniques de métrologie. Pour ce faire, des algorithmes de fusion de données sont développés afin de traiter les informations issues de multiples équipements de métrologie. Le but étant donc d’utiliser ce même type de méthode pour la mesure de rugosité de ligne. Ces travaux de thèse explicitent tout d’abord les progrès de méthodologie de mesure de rugosité de ligne au travers de la décomposition fréquentielle et des modèles associés. Les différentes techniques utilisées pour la mesure de rugosité de lignes sont présentées avec une nouveauté importante concernant le développement et l’utilisation de la technique SAXS pour ce type de mesure. Cette technique possède un potentiel élevé pour la détermination de motifs sub nanométriques. Des étalons de rugosités de ligne sont fabriqués, sur la base de l’état de l’art comportant des rugosités périodiques, mais aussi, des rugosités plus complexes déterminées par un modèle statistique utilisé normalement pour la mesure. Ces travaux se focalisent finalement sur les méthodes d’hybridation et plus particulièrement sur l’utilisation de réseaux de neurones. Ainsi, la mise en place d’un réseau de neurones est détaillée au travers de la multitude de paramètres qu’il comporte. Le choix d’un apprentissage du réseau de neurones sur simulation mène à la nécessité de savoir générer les différentes métrologies en présence
Roughness at Sub-nanometric scale determination becomes a critical issue, especially for patterns with critical dimensions below 10nm. Currently, there is no metrology technique able to provide a result with high precision and accuracy. A way, based on hybrid metrology, is currently explored and dedicated to dimensional measurements. This hybrid metrology uses data fusion algorithms in order to address data coming from different tools. This thesis presents some improvements on line roughness analysis thanks to frequency decomposition and associated model. The current techniques used for roughness determination are explained and a new one SAXS (Small Angle X-rays Scattering) is used to push again limits of extraction of roughness. This technique has a high potential to determine sub nanometrics patterns. Moreover, the design and manufacturing of reference line roughness samples is made, following the state of art with periodic roughness, but also more complex roughness determined by a statistical model usually used for measurement. Finally, this work focus on hybridization methods and more especially on neural network utilization. Thus, the establishment of a neural network is detailed through the multitude of parameters which must be set. In addition, training of the neural network on simulation leads to the capability to generate different metrology

Thesis (M.Comm. (Accountancy))--University of Stellenbosch, 2005.
ENGLISH ABSTRACT: A technique that may be used to incorporate Risk Based Internal Auditing (RBIA) in the IT environment is to follow annual audit planning methodology steps. The IT infrastructure elements are linked to the business processes which they support. Their ranking are based on the risk assessments of the business process, the business process priority, the dependency of the business process on IT and the IT infrastructure element’s own risk assessment. CobiT is used as an auditing method, i.e. best practice guidance to audit against.

In cognitive accounts, language knowledge and learning are depicted as autonomous mental processes, governed by universal principles, and investigated by psychological experiment. However, individuals interact in social space, where language use is regulated by public norms, and embodied in activities, discourses and institutions which establish the criteria for meaning and understanding in a given context. The incompatibility of 'internal' and 'external' explanations is especially evident in relation to literate practices, including reading, whose origins are cultural and historical, which are nevertheless held to depend on specific cognitive processes, and to have consequences for individual cognitive development. The cognitive approach to reading detaches it from context, and, in effect, assumes that western forms of print literacy are timeless and universal. In relation to second language learning, this has made possible a notion of reading as 'exposure to language' which disregards its contextual, discursive properties and its significance as a socially constructed activity. This thesis therefore presents a critique of 'technological' approaches to cognition, learning and literacy, with particular reference to reading in a second language. It argues that theories of this type belong to a recurrent attempt in the western tradition to establish a context-independent, 'alphabetic' concept of the sign, grounded in correspondence to a prior, ahistorical reality. Their evolution is traced through approaches to written language as representation of speech, the rise of the concept of literal meaning, the seventeenth century quest for a 'real' character to represent, hence disclose, the true constituents of natural phenomena, and the definition of autonomous text by exclusion of non-representational language. It is related to the rise of the notion of the brain as a machine for turning out exact representations (propositions, sentences), now embodied in cognitive approaches to language and learning, for which the computer has supplied the chief metaphor. The 'alphabetic' concept of the sign thus underlies current models of the reading process, in which comprehension is depicted as a private representation, the outcome of internal computational processes, but the nature of ordinary reading abilities remains mysterious. Against this, it is argued that no representation determines its own meaning; that understanding is established not by reference to an internal process but in public discourse.

Ce travail de recherche introduit, en trois parties, les principaux "elements pour une approche d'evaluation socio-economique multicritere et de mise en oeuvre de decision d'investir dans une economie en developpement. La premiere partie, intitulee "l'imperfection de l'information, l'incertitude et l'eleboration de decisions d'investir", expose, dans un 1er chapitre le fondement de notre approche par le biais d' "un modele theorique du processus decisionnel (a 4 phases) dans les conditions d'incertitude et d'imperfection de l'information". Les deux premieres phases sont appliquees a la decision d'investir dans un 2eme chapitre sur "la preparation a la decision d'investir". L'application des donnees essentielles de la 3me phase du processus decisionnel a l'"evaluation socio-economique de decision d'investir" (dans une 2eme partie) est realisee en deux etapes consecutives : -fournir les principaux "elements pour une approche d'evaluation socio-economique multicritere de decusion d'investir" (ibjet de 3eme chapitre). -mettre en pratique le cadre general de l'approche proposee (avec reference au secteur industriel algerien dans un 4eme chapitre "evaluation et choix" la reduction des effets de l'incertitude est realisable par l'introduction, dans les differentes etapes de la phase de mise en oeuvre, de deux types de flexibilite. Flexibilite technique et flexibilite organisationnelle
This research is an attempt to develop, in three main parts, "an approach to multicriteria socio-economic appraisal and implementation of investment decisions in a developing economy". The first part revisists the notions : "information imperfections, uncertainty and investment decision making". It introduces in chapter i "a (fourstages) theoretical model for decision making process under conditions of uncertainty and information imperfections". The first two stages are applied, in a second chapter, to "the preparation of investment proposals". The third stage of the model deals, in two consecutive chapters (3 & 4), with "the socio-economic appraisal of investment proposals": , chapter 3 introduces "a framework to multicriteria socio-economic evaluation of investment decisions". , chapter 4 applies the proposed framework (with reference to the algerian industrial sector) to "the evaluation and decision making". The last part of the thesis concerns the reduction of uncertainty effect. This effect can be reduced by means of introducing two types of flexibility (technical flexibility and organisational flexibility) in the various stages of projects implementation

Dans des situations où la perception visuelle est fortement contrainte ou déficiente, il est nécessaire de rendre perceptible l'information dans une modalité non visuelle, tout en prenant en compte des capacités sensorielles et mnésiques humaines. Par exemple, un non-voyant, souhaitant prendre connaissance d'un itinéraire, devra le parcourir de façon non visuelle et le mémoriser. Cependant, outre l'aspect matériel, la mise en œuvre de solutions alternatives (non visuelles) demeure confrontée aux capacités cognitives de l'utilisateur (compréhension, mémorisation, intégration de plusieurs informations, etc.). L'objet de cette thèse est de contribuer à la conception de techniques d'interactions permettant d'optimiser la transmission non visuelle d'informations. A ces fins, j'ai exploré l'apport de la multimodalité comme moyen d'optimisation permettant d'outrepasser les limites de la mémorisation. Je me suis concentré sur l'étude des techniques d'interaction basées sur les modalités auditives et tactiles, en limitant au maximum l'utilisation de la parole, afin de concevoir des techniques pour des environnements différents (flexibilité), d'optimiser l'utilisation de canaux perceptifs (exploitation des propriétés du son dans des messages audio pour transmettre plus d'informations, par exemple), d'éviter de limiter mes techniques par la barrière de la langue ou de sa compréhension et enfin, pour explorer d'autres solutions que la synthèse vocale seule. Les travaux de ma thèse ont mené à la conception, à l'implémentation et à l'évaluation de techniques d'interaction multimodale non visuelle, en réponse à différents contextes, dont, en particulier, ceux de la transmission d'informations de type , (couple de coordonnées) et (séquence de couples direction-distance). Pour parvenir à concevoir mes interactions, j'ai, tout d'abord, effectué une revue de la littérature, afin d'en extraire les principaux facteurs de conception de techniques d'interaction dédiées à la transmission non visuelle d'information. Puis, j'ai organisé ces facteurs sous la forme d'un cadre d'analyse, sur lequel je me suis appuyé pour concevoir chacune de mes techniques. Trois expériences distinctes ont permis d'évaluer l'influence de facteurs de conception sur l'efficacité des interactions et la satisfaction des utilisateurs vis-à-vis des techniques. Je peux, notamment, citer l'implication des utilisateurs (actif ou passif), la présence d'aides explicites", la transmission de plusieurs informations en parallèle et la modalité principale utilisée et, le type de codage dans lequel est encodée l'information
In situations where the visual perception is strongly constraint or deficient, it is necessary to make perceptible the information with a "not visual form" while taking into account human sensory and mnesic capacities. For example, a blind person wishing to acquaint an itinerary must read it under a non visual form and memorize it. However, besides the material aspect, the implementation of alternatives (non-visual) still faces to the cognitive abilities of the user (comprehension, memorization, integration of various information, etc.). The purpose of this thesis is to contribute to the design of interaction techniques allowing to optimize the transmission not visual of the information. For these purposes, I explored the feature of multimodality as a means of optimization, allowing of exceeding the memorization limits. I focused on the study of interaction techniques based on auditory and tactile modalities and by minimizing the use of the speech, in order to develop techniques for different environments (flexibility), optimize the use of perceptual channels (operating the properties of sound in audio messages to transmit more information, for example), avoid limiting my techniques by the language barrier or understanding and finally, to explore alternatives to the synthesised voice alone. The works of my thesis led to the design, to the implementation and to the evaluation of interaction techniques "non-visual" and "multiform", in answer to different contexts, whom in particular those of the information transmission of type , (pair of coordinates) and (sequence of couples direction-distance). To achieve design my interactions, I have made a review of literature in order to extract the main factors of design of interaction techniques dedicated to the transmission not visual of the information. Then, I have organized these factors in an analytical framework on which I have relied to design each of my techniques. Three separate experiments were led to evaluate the influence of design factors on the effectiveness of interactions and satisfaction towards users of technology. I can give some of them, the involvement of users (active or passive), the presence of explicit help, the transmission of several information in parallel, the main modality used and the type of coding in which is encoded the information

The study of neuronal and neurodegenerative diseases requires the development of new tools and technologies to create functional neuroelectronics allowing both stimulation and recording of cellular electrical activity. In the last decade organic electronics is digging its way in the field of bioelectronics and researchers started to develop neural interfaces based on organic semiconductors. The interest in such technologies arise from the intrinsic properties of organic materials such as low cost, transparency, softness and flexibility, as well the biocompatibility and the suitability in realizing all organic printed systems. In particular, organic field-effect transistor (OFET) -based biosensors integrate the sensing and signal amplification in a single device, paving the way to new implantable neural interfaces for in vivo applications. To master the sensing and amplification properties of the OFET-based sensors, it is mandatory to gain an intimate knowledge of the single transistors (without any analytes or cells) that cannot be limited to basic characterizations or to general models. Moreover, organic transistors are characterized by different working principles and properties as respect to their inorganic counterpart. We performed pulsed and transient characterization on different OFETs (both p-type and n-type) showing that, even though the transistors can switch on and off very fast, the accumulation and/or the depletion of the conductive channel continues for times as long as ten seconds. Such phenomenon must be carefully considered in the realization of a biosensor and in its applications, since the DC operative point of the device can drift during the recording of the cellular signals, thus altering the collected data. We further investigate such phenomenon by performing characterizations at different temperatures and by applying the deep level transient spectroscopy technique. We showed that the slow channel accumulation (and depletion) is due to the semiconductor density-of-states that must be occupied in order to bring the Fermi energy level close to the conduction band. This is a phenomenon that can takes several seconds and we described it by introducing a time-depend mobility. We also proposed a technique to estimate the behavior, in time, of the position of the Fermi energy level as respect to the conduction band. To understand the electrochemical transduction processes between living cell and organic biosensor, we realized two-electrodes structure (STACKs) where a drop of saline solution is put directly in contact with the organic semiconductor. On these devices, we performed electrochemical impedance spectroscopy at different DC polarizations and we developed an equivalent circuit model for the metal-organic semiconductor-solution structures that are typically used as transducers in biosensor devices. Our approach was extending the standard range of the bias voltages applied for devices that operate in water. This particular characterization protocol allowed to distinguish and investigate the different mechanisms that occur at the different layers and interfaces: adsorption of ions in the semiconductor; accumulation and charge exchange of carriers at the semiconductor/electrolyte interface; percolation of the ionic species through the organic semiconductor; ion diffusion across the electrolyte; ion adsorption and charge exchange at the platinum interface. We highlighted the presence of ion percolation through the organic semiconductor layer, which is described in the equivalent circuit model by means of a de Levie impedance. The presence of percolation has been demonstrated by environmental scanning electron microscopy and profilometry analysis. Although percolation is much more evident at high negative bias values, it is still present even at low bias conditions. In addition, we analyze two case studies of devices featuring NaCl (concentration of 0.1M) and MilliQ water as solution, showing that both cases can be considered as a particular case of the general model presented in this manuscript. The very good agreement between the model and the experimental data makes the model a valid tool for studying the transducing mechanisms between organic films and the physiological environment. Hence this model could be a useful tool not only for the characterization and failure analysis of electronic devices, such as water-gated transistors, electrophysiological interfaces, fuel cells, and others electrochemical systems, but also this model might be used in other applications, in which a solution is in intimate contact with another material to determine and quantify, if undesired mechanisms such as percolation and/or redox corrosive processes occur. Lastly, the knowledge gain on OFETs and STACKs were put together to realize electrolyte-gated field effect transistors (EGOFETs). We then developed a model to describes EGOFETs as neural interfaces. We showed that our model can be successfully applied to understand the behaviour of a more general class of devices, including both organic and inorganic transistors. We introduced the reference-less (RL-) EGOFET and we showed that it might be successfully used as a low cost and flexible neural interface for extracellular recording in vivo without the need of a reference electrode, making the implant less invasive and easier to use. The working principle underlying RL-EGOFETs involves self-polarization and back-gate stimulation, which we show experimentally to be feasible by means of a custom low-voltage high-speed acquisition board that was designed to emulate a real-time neuron response. Our results open the door to using and optimizing EGOFETs and RL-EGOFETs for neural interfaces.
Lo studio delle malattie neuronali e neuro-degenerative richiede lo sviluppo di nuovi strumenti e tecnologie per creare dispositivi neuro-elettronici funzionali che consentano sia la stimolazione che la registrazione dell'attività elettrica cellulare. Nell'ultimo decennio l'elettronica organica sta emergendo nel campo della bioelettronica e diversi gruppi di ricerca hanno iniziato a sviluppare interfacce neurali basate su semiconduttori organici. L'interesse per tali tecnologie deriva dalle proprietà intrinseche dei materiali organici quali basso costo, trasparenza, morbidezza e flessibilità, nonché la biocompatibilità e l'idoneità nella realizzazione di sistemi stampati completamente organici. In particolare, i biosensori basati sulla tecnologia a transistor ad effetto campo organico (OFET) integrano il sensing e l'amplificazione del segnale in un singolo dispositivo, aprendo la strada a nuove interfacce neurali impiantabili per applicazioni in vivo. Per padroneggiare le proprietà di rilevamento e amplificazione dei sensori basati su OFET, è obbligatorio acquisire una conoscenza approfondita dei singoli transistor (senza la presenza di analiti e/o cellule) che vadano oltre le caratterizzazioni di base o modelli generali. Inoltre, i transistor organici sono caratterizzati da diversi principi di funzionamento e diverse proprietà rispetto alla loro controparte inorganica. In questo lavoro abbiamo svolto caratterizzazioni impulsate e transienti su diversi OFET (sia di tipo p che di tipo n) mostrando che, anche se i transistor possono accendersi e spegnersi molto velocemente, l'accumulo e/o lo svuotamento del canale conduttivo continua per tempi che possono superare le decine di secondi. Tale fenomeno deve essere attentamente considerato nella realizzazione di un biosensore e nelle sue applicazioni, poiché il punto operativo DC del dispositivo può andare alla deriva durante la registrazione dei segnali cellulari, alterando così i dati raccolti. Questo fenomeno viene ulteriormente approfondito caratterizzano i dispositivi a diverse temperature e per mezzo della tecnica DLTS. Abbiamo dimostrato che il lento accumulo (e svuotamento) del canale è dovuto alla densità di stati del semiconduttore organico che devono poter essere occupati per portare il livello energetico di Fermi vicino alla banda di conduzione. Questo è un fenomeno che può richiedere diversi secondi che possiamo descrivere introducendo una mobilità dipendente dal tempo. Per comprendere i processi di trasduzione elettrochimica tra cellule viventi ed il biosensore organico, abbiamo realizzato una struttura a due elettrodi (STACK) in cui una goccia di soluzione salina viene messa direttamente a contatto con il semiconduttore organico. Su questi dispositivi, abbiamo eseguito la spettroscopia di impedenza elettrochimica a diverse polarizzazioni DC e abbiamo sviluppato un modello circuitale equivalente per le strutture metallo/semiconduttore organico/soluzione che vengono tipicamente utilizzate per la realizzazione di bio-trasduttori. Il nostro approccio prevede di estendere il range standard delle tensioni operative per questo genere di dispositivi. Ciò ha permesso di investigare e distinguere i diversi fenomeni che si verificano nei diversi strati e interfacce: adsorbimento di ioni nel semiconduttore; accumulo e scambio di cariche di portanti all'interfaccia semiconduttore/elettrolita; percolazione delle specie ioniche attraverso il semiconduttore organico; diffusione di ioni attraverso l'elettrolita; adsorbimento di ioni e scambio di carica all'interfaccia col metallo. Abbiamo evidenziato la presenza di percolazione ionica attraverso lo strato di semiconduttore organico, che è descritto nel modello circuitale per mezzo di un'impedenza di de Levie. La presenza di percolazione è stata dimostrata mediante microscopia elettronica a scansione ambientale e analisi profilometrica. Sebbene la percolazione sia molto più evidente a valori di bias negativi elevati, risulta presente anche a basse condizioni di bias. L'ottimo accordo tra il modello e i dati sperimentali rende il modello un valido strumento per studiare i meccanismi di trasduzione tra film organici e l'ambiente fisiologico. Quindi questo modello può essere uno strumento utile non solo per la caratterizzazione e l'analisi dei guasti dei dispositivi elettronici, come water-gated transistor, interfacce elettrofisiologiche, celle a combustibile e altri sistemi elettrochimici, ma anche nel caso in cui una soluzione è in intimo contatto con un altro materiale per determinare e/o quantificare se si verificano meccanismi indesiderati come percolazione e/o processi corrosivi. Infine, il bagaglio di conoscenze ottenuto studiando i dispositivi OFET e STACK è stato messo utillizato per realizzare dispositivi EGOFET. Abbiamo quindi sviluppato un modello per descrivere gli EGOFET come interfacce neurali. Abbiamo dimostrato che il nostro modello può essere applicato con successo per comprendere il comportamento di una classe più generale di dispositivi, compresi i transistor sia organici che inorganici. Abbiamo introdotto l'RL-EGOFET (reference-less EGOFET) e abbiamo dimostrato che questa struttura può essere utilizzata con successo come interfaccia neurale flessibile per il recording extracellulare in vivo senza la necessità di un elettrodo di riferimento, rendendo l'impianto meno invasivo e più facile da usare. I nostri risultati aprono la strada all'utilizzo e all'ottimizzazione di EGOFET e RL-EGOFET come interfacce neurali.

Natural ventilation is the dominating ventilation process in ancient buildings like churches, and also in most domestic buildings in Sweden and in the rest of the world. These buildings are naturally ventilated via air infiltration and airing. Air infiltration is the airflow through adventitious leakages in the building envelope, while airing is the intentional air exchange through large openings like windows and doors. Airing can in turn be performed either as single-sided (one opening) or as cross flow ventilation (two or more openings located on different walls). The total air exchange affects heating energy and indoor air quality. In churches, deposition of airborne particles causes gradual soiling of indoor surfaces, including paintings and other pieces of art. Significant amounts of particles are emitted from visitors and from candles, incense, etc. Temporary airing is likely to reduce this problem, and it can also be used to adjust the indoor temperature. The present study investigates mechanisms and prediction models regarding air infiltration and open-door airing by means of field measurements, experiments in wind tunnel and computer modelling. In natural ventilation, both air infiltration and airing share the same driving forces, i.e. wind and buoyancy (indoor-outdoor temperature differences). Both forces turn out to be difficult to predict, especially wind induced flows and the combination of buoyancy and wind. In the first part of the present study, two of the most established models for predicting air infiltration rate in buildings were evaluated against measurements in three historical stone churches in Sweden. A correction factor of 0.8 is introduced to adjust one of the studied models (which yielded better predictions) for fitting the large single zones like churches. Based on field investigation and IR-thermography inspections, a detailed numerical model was developed for prediction of air infiltration, where input data included assessed level of the neutral pressure level (NPL). The model functionality was validated against measurements in one of the case studies, indicating reasonable prediction capability. It is suggested that this model is further developed by including a more systematic calibration system for more building types and with different weather conditions. Regarding airing, both single-sided and cross flow rates through the porches of various church buildings were measured with tracer gas method, as well as through direct measurements of the air velocity in a porch opening. Measurement results were compared with predictions attained from four previously developed models for single‑sided ventilation. Models that include terms for wind turbulence were found to yield somewhat better predictions. According to the performed measurements, the magnitude of one hour single-sided open-door airing in a church typically yields around 50% air exchange, indicating that this is a workable ventilation method, also for such large building volumes. A practical kind of diagram to facilitate estimation of suitable airing period is presented. The ability of the IDA Indoor Climate and Energy (IDA-ICE) computer program to predict airing rates was examined by comparing with field measurements in a church. The programs’ predictions of single-sided airflows through an open door of the church were of the same magnitude as the measured ones; however, the effect of wind direction was not well captured by the program, indicating a development potential. Finally, wind driven air flows through porch type openings of a church model were studied in a wind tunnel, where the airing rates were measured by tracer gas. At single-sided airing, a higher flow rate was observed at higher wind turbulence and when the opening was on the windward side of the building, in agreement with field measurements. Further, the airing rate was on the order of 15 times higher at cross flow than at single-sided airing. Realization of cross flow thus seems highly recommendable for enhanced airing. Calibration constants for a simple equation for wind driven flow through porches are presented. The measurements also indicate that advection through turbulence is a more important airing mechanism than pumping.   The present work adds knowledge particularly to the issues of air infiltration and airing through doors, in large single zones. The results can be applicable also to other kinds of large single-zone buildings, like industry halls, atriums and sports halls.
Naturlig ventilation är den dominerande ventilationsprocessen i äldre byggnader såsom kyrkor, och även i de flesta småhus i Sverige och övriga delar av världen. Luftinfiltration och vädring utgör viktiga komponenter i naturlig ventilation, där luftinfiltration är luftflöde genom oavsiktliga läckage i byggnadsskalet, medan vädring är avsiktligt luftutbyte genom stora öppningar såsom fönster och dörrar/portar. Vädring kan i sin tur ske ensidigt (genom en öppning) eller som tvärdrag (genom två eller flera öppningar belägna på olika ytterväggar). Det totala luftutbytet påverkar värmeförluster och inomhusluftens kvalité. I kyrkor orsakar avsättning av luftpartiklar en gradvis nedsmutsning av invändiga ytor, inklusive väggmålningar och andra konstföremål. Betydande mängder partiklar avges från besökare, tända ljus, rökelse, o.d. Tillfällig vädring kan minska detta problem, men även användas för att justera innetemperaturen. Föreliggande studie analyserar mekanismer och predikteringsmodeller gällande luftinfiltration och dörrvädring genom fältmätningar, vindtunnelförsök och datorsimuleringar. Luftinfiltration och vädring har samma drivkrafter, d.v.s. vind och termik (inne‑ute temperaturskillnader). Båda dessa drivkrafter är svåra att predicera, särskilt vindinducerade flöden och kombinationen av termik och vind. Två av de mest etablerade modellerna för luftinfiltrationsprediktering i byggnader har utvärderats via mätningar i tre kulturhistoriska stenkyrkor i Sverige. En korrigeringsfaktor av 0,8 föreslås för bättre prediktion av den ena modellen (som gav bäst resultat) gällande höga en-zonsbyggnader såsom kyrkor. En detaljerad numerisk modell är utvecklad för luftinfiltrationsprediktering, där indata baseras på fältundersökningar, inkl. IR-termografering och uppmätt av neutrala tryckplanet (NPL). Modellens funktionalitet har validerats via mätningar i en av fallstudierna och pekar på tämligen god prediktionsprestanda. Vidare utveckling av modellen föreslås, inkl. ett mer systematiskt kalibreringssystem, för olika typer av byggnader och väderförhållanden. Gällande vädring mättes både ensidigt flöde och tvärdrag genom portar i olika kyrkobyggnader med hjälp av spårgas samt direkta lufthastighetsmätningar i portöppning. Mätresultaten jämfördes med erhållna prediktioner från fyra tidigare utvecklade modeller för ensidig ventilation. De modeller som tog hänsyn till vindturbulens gav något bättre resultat. Enligt utförda mätningar medför en timmes ensidig portvädring i en kyrka cirka 50 % luftutbyte, vilket indikerar att detta är en tillämpbar ventilationsmetod, även för så pass stora byggnadsvolymer. Ett särskilt vädringsdiagram presenteras, som syftar till att underlätta uppskattning av erforderlig vädringsperiod. Vidare studerades predikteringsprestanda hos IDA Indoor Climate and Energy (IDA-ICE) simuleringsprogram avseende vädring, där simuleringsdata jämfördes med fältmätningar i en kyrka. Programmets prediktion av ensidigt luftflöde genom en öppen kyrkport var av samma storlekordning som det uppmäta; dock klarade programmet inte av att hantera inverkan av vindriktning så väl, vilket pekar på en utvecklingspotential. Avslutningsvis undersöktes vinddrivet flöde igenom portöppningar i en kyrkmodell i vindtunnel, där luftomsättningen mättes med hjälp av spårgasmetoden. Vid ensidig vädring observerades högre flöde vid högre vindturbulens och när öppningen var på vindsidan av byggnaden, i överensstämmelse med fältmätningarna. Dessutom var vädringsflödet vid tvärdrag i storleksordningen 15 högre än det vid ensidig vädring. Det verkar alltså som att man kan öka vädringstakten avsevärt om man kan åstadkomma tvärdrag. Kalibreringskonstanter presenteras också för en enkel ekvation för vinddrivet flöde genom portar. Vindtunnelstudien indikerar vidare att advektion genom turbulens är en viktigare vädringsmekanism än pumpning. Föreliggande arbete bidrar med kunskap speciellt kring luftinfiltration och vädring genom portar i höga en-zonsbyggnader. Resultaten kan även vara tillämpliga på andra typer av höga en-zonsbyggnader såsom industrihallar, atrier/ljusgårdar och idrottshallar.
Church project

Inter-Cell Interference (ICI) will be one of main problems for degrading the performance of future wireless networks at cell edge. This adverse situation will become worst in the presence of dense deployment of micro and macro cells. In this context, the Coordinated Multi-Point (CoMP) technique was introduced to mitigate ICI in Next Generation Wireless Networks (NGWN) and increase their network performance at cell edge. Even though the CoMP technique provides satisfactory solutions of various problems at cell edge, nevertheless existing CoMP handover schemes do not prevent unnecessary handover initialisation decisions and never discuss the drawbacks of CoMP handover technique such as excessive feedback and resource sharing among UEs. In this research, new CoMP-based handover schemes are proposed in order to minimise unnecessary handover decisions at cell edge and determine solution of drawbacks of CoMP technique in conjunction with signal measurements such as Reference Signal Received Power (RSRP) and Received Signal Received Quality (RSRQ). A combination of calculations of RSRP and RSRQ facilitate a credible decision making process of CoMP mode and handover mode at cell edge. Typical numerical experiments indicate that by triggering the CoMP mode along with solutions of drawbacks, the overall network performance is constantly increase as the number of unnecessary handovers is progressively reduced.

Si la vidéo est d’un usage courant à la télévision et dans la pratique amateur depuis plusieurs décennies, sa mise en contact avec des films tournés sur pellicules 16 ou 35mm traditionnelles est plus occasionnelle, tout en offrant de nouvelles possibilités esthétiques. En conservant la texture particulière de la vidéo dans un mélange et une confrontation des formats, un effet peut se produire. La création de cet « effet vidéo » est l’objet de notre étude. Que peut l’apparition d’une image vidéo, définie et lisible comme telle, à l’intérieur d’une oeuvre de fiction ou de documentaire dont le support de référence est le celluloïd ? Nous examinerons ainsi certains films de [notamment] Robert Kramer, William Klein, Michael Haneke, Fritz Lang, Jean-Luc Godard, Atom Egoyan, David Cronenberg, David Lynch, Abbas Kiarostami, Abel Ferrara, Wim Wenders, Chris Marker ou Jean-Daniel Pollet. Ayant déterminé le support de référence, nous constaterons que ces images renvoient à un type particulier d’effet vidéo [télévisuel, de surveillance ou amateur-intime], pour étudier ensuite comment ces données peuvent être perverties. Nous analyserons comment la vidéo peut perdre toute justification narrative à l’intérieur de l’œuvre, et infléchir par sa seule texture l’émotion du spectateur, pour éventuellement « faire l’image » [pour reprendre l’expression de Samuel Beckett]. Enfin, en rendant sa nature instable, nous constaterons que l’effet vidéo peut permettre les écarts d’un souffle poétique
Video is currently used on television and as an amateur format, and has been for a few decades. But its mixing with feature movies shot on traditional 16 or 35 millimetres is more occasional, even if it can offer new aesthetical possibilities. By keeping the particular texture of video, in a mix and a confrontation of formats, an effect can occur. The creation of that “video effect” is the subject of this study. What can create a video image [defined and readable as video] when a fiction or a documentary’s reference of format is on celluloid? To that purpose, some films directed by Robert Kramer, William Klein, Michael Haneke, Fritz Lang, Jean-Luc Godard, Atom Egoyan, David Cronenberg, David Lynch, Abbas Kiarostami, Abel Ferrara, Wim Wenders, Chris Marker or Jean- Daniel Pollet will be investigated. These images determine a particular video effect [television, CCTV or amateur-intimate], and its constituting elements can be altered. Video can also lose all its narrative justification and influence the audience’s emotions only through its texture, in order to eventually « make the image » [in reference to Samuel Beckett’s short story]. Finally, by creating instability in the nature of its constitution, the video effect can contain the openness of a poetic whisper

Dans un contexte où les problématiques urbaines, les formes de l'action publique et les systèmes d'acteurs ont bouleversé ces dernières décennies les façons de fabriquer la ville, il s'agit de saisir les logiques d'action qui participent de la dynamique de transformation des espaces et des territoires contemporains. Elaboré sous l'angle de la sociologie urbaine, le modèle d'analyse repose sur trois grands processus interactifs. Un processus de cadrage dont le référentiel donne la mesure en termes de socle de représentations partagées. Un processus d'organisation complexe de ressources et d'hommes dont il faut coordonner et réguler les actions et les interventions au sein de dispositifs techniques , réglementaires et organisationnels spécifiques.Un processus de traduction spatiale, matérielle et formelle visant à la réalisation concrète sur des territoires privilégiés d'opérations, combinant sur la base des intentions initiales et dans le cadre d'un espace d'activités spécifique, autant d'objectifs économiques, sociaux, politiques et symboliques. La notion de projet urbain traduit le chaînage de ces trois processus qui à partir d'un enjeu défini en commun à l'échelle de la ville ou de l'agglomération génère en continuum sur une donnée donnée une activité collective, mobilisant et enrôlant à chaque étape et niveaux de responsabilité, une pluralité d'acteurs autour d'une série d'opérations urbaines et architecturales. Le cas de l'agglomération bordelaise et de ses transformations sur la période 1995-2007 sert de terrain de référence
In a context where urban problems forms of public action and systems of actors drastically change the ways to build the city these last decades, we must understand the logics of action that influence the dynamics of spatial and territorial changes. The analysis model is developed from the point of view of the urban sociology and is based on three important intercative processes. A strategic framing process whose reference system gives the standart in terms of a base of shared representations. A complicated organizational process (networking), involving ressources and persons whose actions and interventions need to be coordonated and controlled within a specifical technical, legal and organisatinal system (urban contracting owner). A process, of a precise, material and spatial translation aiming the concrete realization, on privileged territories of operations which on the basis of the initial intentions and within the framework of a space of specific activities, combine economic, political and symbolic objectives. The concept of urban project is the expression of the chaining of these three processes. Starting from a jointly defined issue on the scale of the city of agglomeration, it generates during a given time period a collective activity, mobilizes and recruits in each stage of all levels of responsabilities a plurality of actors around a serie of urban and architectural operations. The agglomeration of Bordeaux and its transformation over the period 1995-2006 is used as reference base

L'évolution issue du C. I. M. (computer integrated manufacturing) visant à considérer l'intégration de toutes les fonctions de l'entreprise opère une mutation qui l'a fait passer du traitement des données à la gestion des informations computer information management, puis de la communication syntaxique en termes de données à une communication des connaissances et propose ainsi la signification nouvelle de corporate information management pour l'acronyme C. I. M. Par rapport, à ce constat, nous proposons, autour du concept d'ingénierie concourante, la définition d'un référentiel commun pour les différents métiers concernés par un système de production, en réduisant ce domaine aux fonctions de gestion technique, de conception et d'exploitation pour les métiers de la mécanique et de l'automatique. L'architecture D. M. M. S. (design management and manufacturing system) ainsi définie permet à chaque pole de disposer de son propre référentiel métier en relation avec les autres via le poste de gestion technique. La modélisation de cette architecture nécessite la mise en œuvre d'environnements intégrés de production. Dans cette optique, nous présentons l'expérimentation de P. C. T. E. (portable commun tool environment), comme plate-forme d'intégration pour le génie productique. Cette modélisation doit tenir compte de la complexité des systèmes de production due principalement à la distribution de la connaissance tout au long du cycle de vie du produit. Pour ce faire, nous proposons, à l'aide d'un modèle de référence d'un système productique qui s'appuie sur le génie systématique, une méthodologie systémique permettant d'appréhender la complexité et la concourance des systèmes considérés

Thesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society, Technology and Policy Program, 2017.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 101-104).
Although there have recently been many significant digital and technical advances in the electric power industry, rural electrification remains a pressing issue in the developing countries around the world. The International Energy Agency estimates that there are 1.2 billion people globally who lack access to electricity. Planning electrical networks to provide energy access to these primarily rural consumers is complicated by the lack of accurate data by electric utilities in these areas and the increased prevalence of microgrids and low-cost individual energy systems which challenges the traditional definition of energy services. Advanced computational planning tools can allow planners and policymakers to take resource constraints, environmental considerations, interactions between off-grid and traditional grid extension projects, and many other factors into account when designing rural electrification policies and plans. The goal of this thesis is to contribute to the development and application of the Reference Electrification Model (REM), a decision support tool which can help planners design optimal electrical networks for rural electrification purposes. In this thesis, I develop the functionalities of REM through several case studies. I also address the topics of estimating the electrification status of buildings and calculating the cost of upstream network reinforcements due to new load additions in the system. This research emphasizes the need for computational tools like REM to develop both feasible network designs as well as viable energy policies and regulations in order to advance efforts related to rural electrification and energy access around the world.
by Turner Cotterman.
S.M. in Technology and Policy

Depuis les années 20 du siècle précédent, les recherches effectuées dans le champ de la didactique des langues non maternelles ont enregistré l’apparition d’un public spécifique demandeur de formations en langue à des fins spécifiques. Cela a donné lieu à un domaine qui se distingue par la grande diversité de ses contextes ainsi que de ses publics, un domaine qui porte sur un jeu de désignations ou sur une jungle d’appellations qui se confondent pratiquement toutes. C’est dans le but de faire acquérir à ces publics des compétences langagières spécifiques utiles dans la pratique de leur travail qu’enseignants et chercheurs sont appelés à créer des démarches méthodologiques spécifiques.Cette thèse cherche, plus particulièrement, à apporter des éléments de réponse aux demandes des étudiants de la faculté des sciences de la santé, en Syrie, qui ont besoin d’apprendre le français médical et non le français général pour s’en servir plus tard dans leur profession. L’objectif principal de ce travail est, d’une part, d’identifier les besoins réels de ces apprenants en prenant en compte les spécificités de leur domaine et d’autre part, de concevoir un référentiel de formation FOS susceptible de contribuer au développement d’une compétence de communication spécifique appropriée aux exigences de leur terrain socioprofessionnel
Research performed since the twenties in the field of didactics of foreign languages, helped the rise of a certain audience with specific requests in professional language. That gave rise to a domain, which is composed of an important diversity of contexts and publics called "French for Specific Purposes". Teachers and researchers are brought to create specific methodological approach, to help this audience gain specific linguistic skills.This thesis aims at bringing elements of answer to the students of the syrian scientific colleges, particularly to those of the Faculty of Health Sciences. Our purpose is to identify the real needs of the latter, taking into account peculiarities of their domain and to conceive teacher-training frame of reference allowing them to develop oral and written comprehension and expression skills

Spatial collaboration refers to collaboration activities involving physical space. It occurs every day as people work together to solve spatial problems, such as rearranging furniture or communicating about an environmental issue. In this work, we investigate how to support spatial collaboration when the collaborators are not colocated. We propose using shared, interactive representations of the space to support distributed, spatial collaboration. Our study examines viewpoint constraint techniques, which determine how the collaborators individually view the representation, and awareness techniques, which enable the collaborators to maintain an understanding of each other's work efforts. Our work consists of four phases, in which we explore a design space for interactive representations and examine the effects of different viewpoint constraint and awareness techniques. We consider situations where the collaborators use the same viewpoints, different viewpoints, and have a choice in viewpoint constraint techniques. In phase 1, we examine current technological support for spatial collaboration and designed two early prototypes. Phase 2 compares various two-dimensional map techniques, with the collaborators using identical techniques. Phase 3 focuses on three-dimensional virtual environment techniques, comparing similar and different frames of reference. The final phase reuses the favorable techniques from the previous studies and presents a novel prototype that combines both two-dimensional and three-dimensional representations. Each phase of this research is limited to synchronous communication activities and non-professional users working together on everyday tasks. Our findings highlight the advantages and disadvantages of the different techniques for spatial collaboration solutions. Also, having conducted multiple evaluations of spatial collaboration prototypes, we offer a common set of lessons with respect to distributed, spatial collaboration activities. This research also highlights the need for continued study to improve on the techniques evaluated and to consider additional spatial collaboration activities.
Ph. D.

De nombreux procédés de fabrication thermomécanique comme le laminage, le soudage ou encore l’usinage mettent en jeu soit des sollicitations mobiles par rapport à la matière fixe, soit de la matière mobile par rapport à des sollicitations fixes. Dans tous les cas, après un régime transitoire en général assez court, les champs thermiques, métallurgiques et mécaniques associés à ces procédés atteignent un état stationnaire. La recherche de ces états stationnaires à l’aide de la méthode des éléments finis classique nécessite de mettre en œuvre des modèles complexes et couteux où les sollicitations se déplacent par rapport à la matière (ou l’inverse). La recherche directe des états stationnaires a fait l’objet de nombreux travaux de recherche ces trente dernières années. Des méthodes sont aujourd’hui disponibles et pour certaines sont proposées dans des codes de calcul du commerce. Ainsi, une option de calcul dite repère mobile proposée par différents auteurs est disponible dans le logiciel SYSWELD. Cette méthode permet de calculer les états thermique, métallurgique et mécanique stationnaires associés à un procédé de soudage, en résolvant un problème de diffusion-convection en thermique et en intégrant, en mécanique, les équations constitutives du comportement du matériau le long des lignes de courant. Si cette méthode a été utilisée avec succès dans de nombreuses applications, elle présente néanmoins quelques limitations. Ainsi le maillage doit être structuré et la convergence des calculs est en général assez lente. Nous proposons dans cette thèse de résoudre le problème mécanique dans un repère lié aux sollicitations, en nous appuyant sur une méthode de calcul par éléments finis reposant sur l’intégration nodale et la technique SCNI (Stabilized Conforming Numerical Integration). Cette méthode permet l’utilisation de maillages en tétraèdres (ou triangles en 2D) sans rencontrer de problème de verrouillage volumique résultant de l’incompressibilité plastique associée au critère de plasticité de von Mises. Plutôt que de rechercher directement l’état stationnaire, l’idée générale est ici de construire l’état stationnaire à partir d’une analyse transitoire en faisant entrer pas à pas la matière par l’amont et en la faisant sortir par l’aval d’un maillage fixe par rapport aux sollicitations et de taille limitée. L’état stationnaire n’est donc atteint qu’au bout d’un certain temps d’analyse. Après une introduction générale (Chapitre 1) et un état de l’art sur les méthodes existantes (Chapitre 2), nous présentons une approche de simulation du mouvement de matière dans le cadre de la méthode des éléments finis classique sur un problème de soudage (Chapitre 3). Nous y proposons également des conditions aux limites thermiques pertinentes pour calculer directement la distribution de températures en régime stationnaire. La méthode des éléments finis reposant sur l’intégration nodale est ensuite décrite au Chapitre 4. Les avantages et inconvénients de la méthode sont discutés. La méthode est validée sur une application en grandes déformations élastoplastiques, un problème de flexion et une simulation thermomécanique de soudage. La méthode des éléments finis reposant sur l’intégration nodale est alors développée pour prendre en compte un mouvement de matière (Chapitre 5). Trois types de mouvement sont considérés : en translation, circulaire et en hélice. Différentes méthodes de transport de champ sont abordées et discutées ainsi que le couplage thermomécanique. Des perspectives à ce travail sont proposées au Chapitre 6. Les perspectives envisagées visent d’une part à améliorer la méthode proposée et d’autre part, à développer la méthode pour simuler d’autres procédés. Une première application de la méthode à la simulation de la coupe orthogonale y est présentée
In the numerous thermomechanical manufacturing processes such as rolling, welding, or even machining involve either moving loads with respect to the fixed material or moving material with respect to fixed loads. In all cases, after a transient regime which is generally quite short, the thermal, metallurgical, and mechanical fields associated with these processes reach a steady state. The search for these stationary states using the classical finite element method requires the implementation of complex and expensive models where the loads move with respect to the material (or vice versa). The steady-state simulation in one increment has been the subject of much researches over the past thirty years. Methods are now available and some are integrated into calculation codes commercial. Thus, a so-called Moving Reference Frame method proposed by various authors is available in the SYSWELD software. This method makes it possible to calculate the steady-state of thermal, metallurgical, and mechanical states associated with a welding process, by solving a thermal diffusion-convection problem in thermal-metallurgy and by integrating, in mechanics, the constitutive equations of the material along the streamline. Moreover, this method has been used successfully in many applications, it nevertheless has some limitations. Thus the mesh must be structured and the convergence of computations is generally quite slow. In this thesis, we propose to solve the mechanical problem in a frame linked to the solicitations, by relying on a finite element calculation method based on nodal integration and the SCNI (Stabilized Conforming Numerical Integration) technique. This method allows the use of tetrahedron meshes (or 2D triangles) without encountering a locking problem resulting from the plastic incompressibility associated with the von Mises plasticity criterion. Rather than directly calculating the steady-state, the general idea here is to construct the steady-state from a transient analysis by bringing material step by step upstream and by making it exit downstream of a fixed mesh related to the solicitations and of the limited mesh size. The steady-state is therefore only achieved after certain steps of analysis. Apart from a general introduction (Chapter 1) and a state of the art on the existing methods (Chapter 2), we present an approach of simulation of the movement of material within the framework of the classical finite element method on a welding problem (Chapter 3). We also provide relevant thermal boundary conditions for directly calculating the steady-state of temperature distribution. The finite element method based on the nodal integration technique is then described in Chapter 4. The advantages and disadvantages of the method are discussed. The nodal-integration-based finite element is validated by comparing its simulation results with classical finite element methods in large elastoplastic strains, a bending problem, and a thermomechanical simulation of welding. The nodal-integration-based finite element is then developed and applied to simulate material motion (Chapter 5). Three types of movement are considered: translational, circular, and helical. Different methods of field transport are approached and discussed as well as thermomechanical coupling. Perspectives for this work are presented in Chapter 6. The envisaged perspectives aim, on the one hand, to improve the proposed method and on the other hand, to develop the method to simulate other processes. A first application of the material motion method to the simulation of the orthogonal cut is presented there