L’objectif de ma thèse est d’étendre les modèles électromagnétiques existants à l’Institut Fresnel pour les fréquences optiques vers le domaine des fréquences térahertz (THz), pour mieux comprendre les phénomènes physiques mis en jeu lors d’interaction onde-matière. Cette compréhension permettrait d’améliorer l’analyse des images THz acquises et de mieux définir les configurations des systèmes optiques utilisés. Ce travail est réalisé en comparant les résultats issus de la modélisation avec ceux provenant d’expériences menées par imagerie THz au sein de l’entreprise Terahertz Waves Technologies. Dans le futur, la modélisation pourrait devenir un outil prédictif pour la caractérisation de matériaux dans le domaine THz.Les ondes THz se situent entre l’infrarouge lointain et les micro-ondes dans le spectre électromagnétique allant de 0.01 mm à 3 mm (ou 100 GHz à 30 THz). Ces ondes bénéficient des avantages des ondes optiques et des micro-ondes dépendant des longueurs d’ondes utilisées. L’imagerie THz présente un fort potentiel pour la caractérisation de la matière, car ces ondes peuvent pénétrer beaucoup de matériaux qui sont opaques dans le visible et dans l’infrarouge. La détection de défauts, les délaminations, la présence d’humidité, etc…, sont un exemple des problématiques qui peuvent être investiguées grâce au rayonnement THz.Dans un premier temps, j’ai pu simuler la réponse optique d’échantillons polymères plans homogènes et isotropes avec de bons accords entre le calcul et la mesure. Ces résultats ont permis de réaliser de premières modélisations d’images en adéquation avec l’imagerie THz. L’étude est ensuite élargie aux matériaux anisotropes qui existent dans l’environnement industriel actuel ainsi qu’aux objets de forme cylindrique. Les modèles développés considèrent l’indice de réfraction complexe d’un échantillon et son épaisseur, c’est pourquoi un chapitre est dévolu à la méthode d’estimation de ces paramètres à partir de mesures issues de spectroscopie THz dans le domaine temporel mise en œuvre. / The aim of my thesis is to extend the electromagnetic models already existing at the Institut Fresnel for the optical frequencies towards the terahertz (THz) range, to have a better knowledge of the physical phenomena involved in THz light-matter interactions. This understanding would allow to improve the analysis of the THz images acquired and to have a better definition of the optical systems configurations that we use. To achieve this work, we compare the results coming from the model with those from the experiments led by THz imaging by Terahertz Waves Technologies. In the future, the modelling could become a predictive tool for the characterization of materials in the THz domain.THz waves are located between far infrared and microwaves in the electromagnetic spectrum going from 0.01 mm to 3 mm (or 100 GHz to 30 THz). These waves benefit from advantages of the optical waves and from microwaves depending on used frequencies. THz imaging presents a high potential one for the characterization on the material, because these waves can penetrate a lot of materials which are opaque in the visible and the infrared lights. Detection of defects, delaminations, the presence of humidity, etc…, are examples of the problems which can be investigated with THz light.At first, I was able to model the optical response of planar, homogenous, isotropic and polymeric samples with good agreements between the calculation and the measurement. These results allowed to realize first modellings of images which are consistent with THz imaging. Therefore, the study is enlarged to anisotropic materials which exist in the current industrial environment as well as the objects of full cylindrical shape. The developed models consider the complex refractive index of a sample and its thickness, that is why a chapter is devoted to the method of estimation of these parameters from measurements coming from THz Time-Domain Spectrocopy signals which was implemented.

Le tungstène sera soumis à des conditions extrêmes de température et de bombardement de particules en tant que paroi des cibles du divertor dans le réacteur de fusion nucléaire ITER. De hauts flux d’ions légers impacteront la surface du tungstène et sont susceptibles de générer des défauts dans le cristal. Cette étude vise à étudier les premières étapes de la formation des défauts lacunaires dans le cristal de tungstène soumis à un faible flux d’ions de faible énergie afin de comprendre le rôle de l’accumulation de l’hélium, un des produits de la réaction de fusion du deutérium et du tritium. Pour cette étude, une source plasma ICP-RF a été développée et qualifiée afin de réaliser des implantations d’hélium dans des conditions parfaitement contrôlées. Les implantations d’hélium ont été réalisées pour plusieurs conditions de fluence, d’énergie et de température, sur des échantillons de tungstène polycristallins. La spectroscopie d’annihilation des positons a été utilisée pour caractériser les défauts lacunaires, les analyses par réactions nucléaires, pour quantifier l’hélium implanté et la spectrométrie de thermodésorption pour caractériser les interactions de l’hélium dans le cristal. Les résultats montrent que pour une énergie de 320 eV à température ambiante, une fluence incidente limite est atteinte à partir de laquelle une saturation de l’hélium implanté apparaît et la formation de lacunes de grande taille débute. L’étude de l’influence de l’énergie et de la température montre l’importance de la répartition de l’hélium en profondeur et de sa mobilité dans le cristal sur la taille et la diversité des défauts formés. Les implantations sont simulées par dynamique moléculaire. Les résultats obtenus par l’approche numérique sont comparés aux résultats expérimentaux afin de mieux comprendre les mécanismes élémentaires mis en jeu. / Tungsten will be exposed to severe plasma conditions such as high temperature and high particle bombardment as a target of the divertor in the nuclear fusion reactor ITER. High fluxes of light ions will impact its surface and can generate defects in the crystal. This study means to observe the first steps of the vacancy-type defects formation in the tungsten crystal subject to low ion flux of low kinetic energy in order to understand the influence of the accumulation of helium, one of the nuclear reaction products. For the experiments, an ICP-RF plasma source was developed and characterized to perform helium implantations under perfectly controlled conditions. Helium implantations were performed under various conditions of fluence, energy and substrate temperature on polycrystalline tungsten samples. Positron annihilation spectroscopy was used to characterize vacancy-type defects, nuclear reaction analysis to quantify implanted helium and thermal desorption spectrometry to characterize the interactions of helium in the crystal. Results show that, for a kinetic energy of 320 eV and at room temperature, a saturation of the helium implanted quantity is reached for a limit incident fluence and that large vacancy defects starts to form. Study of the kinetic energy and the surface temperature influences show the importance of the depth distribution and the mobility of the helium in the crystal on the size and the diversity of the generated defects. Implantations are performed by molecular dynamic simulations. Results obtained by the numerical approach are compared to experimental ones in order to get a better understanding of the atomic scale mechanisms.

Les choix et préférences des consommateurs pour les aliments sont largement conditionnés par leurs propriétés sensorielles, et notamment par les perceptions aromatiques dans le cas des boissons alcoolisées. Un des enjeux des industriels du secteur pour contrôler et développer les ventes des produits est de mieux comprendre les déterminants de la qualité sensorielle de ces produits. Les travaux réalisés dans le cadre de ce projet de thèse concernent les cognacs et visent à appréhender les liens entre la composition des produits, les étapes du processus d’élaboration, dont la phase de vieillissement, et leurs caractéristiques sensorielles finales. L’objectif est notamment de comprendre l’impact des constituants de la matrice des cognacs sur la libération et la perception des composés d’arôme. Pour répondre à cet objectif, une stratégie fondée sur des approches sensorielle et physicochimique a été mise en œuvre. Les travaux réalisés en évaluation sensorielle ont permis de montrer l’absence d’impact des constituants non-volatils et de réaffirmer l’importance des composés d’arôme dans la perception des différences sensorielles entre les cognacs. Le suivi des libérations de composés d’arôme par PTR-MS au cours de la consommation des cognacs a été possible par la mise au point de conditions opératoires compatibles avec la teneur élevée en éthanol des produits. Ces travaux ont montré que les composés d’arôme clés pour la perception des cognacs étaient libérés en plus grandes quantités dans les cognacs les plus âgés. En revanche, aucune différence entre les produits n’a été constatée au niveau de la temporalité de ces libérations. L’application des approches statistiques prédictives a finalement permis de montrer qu’il est possible de prédire les propriétés sensorielles des cognacs à partir de certaines de leurs caractéristiques physicochimiques, et que les corrélations établies entre les variables physicochimiques et sensorielles pouvaient être expliquées qualitativement grâce aux connaissances existantes dans la littérature et à celles des experts, notamment concernant leur processus d’élaboration. / Consumer’s choices and preferences for foods are widely influenced by their sensory properties, and especially by aromatic perceptions in the case of alcoholic beverages. One of the challenges of wine and spirit industries for controlling and developing product sales is to gain insights on the determinants of the sensory quality of their products. The work carried out during this PhD project concerns cognacs and aim to apprehend the links between product composition, the stages in their elaboration process, including maturation, and their final sensory properties. An important objective is to understand the impact of cognac matrix components on aroma compounds release and perception. To fulfill this objective, a strategy based on the use of physicochemical and sensory approaches was set up. Sensory evaluation enabled to highlight the absence of impact of non-volatile components and to reaffirm the essential effect of aroma compounds for the perception of sensory differences between cognacs. The monitoring of the release of aroma compounds by PTR-MS during cognac consumption has been possible by the setting up of operating conditions allowing the analysis of high ethanol-containing beverages. These works have shown that key aroma compounds for cognac perception were released in higher amounts in the oldest cognacs. However, no difference was observed concerning their temporality of release. The development of statistical approaches finally showed that it was possible to predict the sensory properties of cognacs from their physicochemical characteristics. Correlations between physicochemical and sensory variables could be qualitatively explained in reference to the knowledge on the elaboration process of cognac in the literature and held by experts.

I dagens skola har det givits större plats till den laborativa matematikundervisningen för att minska den teoretiska tysta räkningen. Det här kommer studien att fördjupa sig igenom frågeställningarna:   ·      Vilka laborativa material använder lärare i grundskolans yngre åldrar i matematikundervisningen inom addition och subtraktion i Gävleområdet? ·      Vilka upplevelser har lärare i Gävleområdet av det laborativa arbetssättet i matematikundervisningen? Och vad deras upplevelser beror på? ·      På vilket sätt kan en lektion med ett laborativt material inom området addition och subtraktion, skapa a-didaktiska-situationer?   Två metoder kommer att användas för att samla in data för studien: två enkäter och en observation genom ett teoretiskt ramverk. Enkäterna visar vilka laborativa material som lärare använder i Gävleområdet, samt deras upplevelser kring materialet. Observationen är en fallstudie där eleverna får arbeta med laborativt material och resultatet visar att det laborativa materialet ökar elevernas kommunikation kring innehållet. Resultatet från undersökningarna stärks även av tidigare forskning som tyder på att laborativ undervisning har en positiv effekt på elevers kunskapsutveckling.

Low-loss waveguides with minimal dispersion are desired throughout the electromagnetic spectrum. These properties are difficult to achieve in the Terahertz (THz) region due to material and geometric constraints. This thesis focuses on the design, fabrication, and testing of waveguide-based devices using two promising technologies: the free-space metallic-slit waveguide (MSWG) and the coplanar strip (CPS) waveguide on a thin (1 um) commercial silicon nitride membrane. The work presented here differs from standard THz waveguide research which commonly uses the field radiated by a photoconductive antenna (THz optics) for excitation and detection. To improve upon system integration, a focus is placed on planar waveguide devices without refractive THz elements. Three main waveguide devices are investigated. First, an edge-coupled MSWG-based linear tapered slot antenna (LTSA) was used for THz-Time Domain Spectroscopy (TDS). This device functions as an alternative to a standard photoconductive switch coupled to a silicon lens and maintains comparable performance. Next an edge-coupled tapered MSWG was investigated. The MSWG conductor separation was increased to a low-loss configuration where the field propagated for 24 mm, after which the conductors were tapered to focus the field onto the receiving active region where a THz-bandwidth pulse was detected. Finally a CPS waveguide was fabricated on a thin silicon nitride membrane where a THz-bandwidth pulse was detected after propagating for 10 mm. The active regions for this device were fabricated using a unique method. This method results in the creation of thousands of small (40 um x 20 um) active regions (from a 4 mm x 4 mm host substrate) which can be placed anywhere for THz excitation and detection. The small active regions in conjunction with the CPS waveguide on the silicon nitride membrane provide an excellent platform for THz system testing. A single membrane can host many THz circuits which can be made ``active" by the placement of a few thin-film photoconductive devices. Main potential future applications include waveguide-based spectroscopy and coherent THz-bandwidth circuit analysis. / Graduate

Notre recherche porte sur la question de l'enseignement de l'algèbre linéaire au niveau universitaire, plus précisément sur les applications linéaires en Classes Préparatoires aux Grandes Écoles. La théorie des situations didactiques avec la sémiotique de Peirce fournissent le cadre principal de nos travaux et nous permettent d'analyser les raisonnements produits par les étudiants en situation d'interrogation orale. Nous proposons dans un premier temps des éléments d'analyse épistémologique concernant le rôle des applications linéaires dans l'émergence de l'algèbre linéaire. Puis nous présentons dans une optique d'analyse didactique les principaux éléments de la sémiotique de Peirce et son algébrisation par le treillis des classes de signes. Nous complétons alors le modèle d'analyse des raisonnements de Bloch et Gibel et proposons un outil d'analyse sémiotique, le diagramme sémantique. Nous utilisons cet outil pour une analyse sémiotique locale a priori d'une situation mathématique. Cette analyse met en évidence le lien entre les premiers signes et premières actions de la situation et la sémiose qui en découle. Nous procédons ensuite à une analyse des raisonnements produits par des étudiants en situation d'interrogation orale, dite « classique ». Cette analyse confirme le lien entre l'absence de niveaux de milieu adidactiques et la difficulté sémantique d'organiser les objets en situation de preuve. Puis, nous expérimentons une situation d'interrogation orale de telle sorte que les niveaux de milieu adidactiques soient riches et stabilisés. L'analyse des raisonnements produits dans cette situation nous permet de montrer que les étudiants sollicitent un point de vue sémantique sur les objets utile lors de leurs validations et contrôles. Ces trois moments de notre travail confirment l'importance du discours et des pratiques heuristiques dans le cadre de l'algèbre linéaire. / Our research is concerned with the teaching of linear algebra at the university level. More precisely, it focuses on the teaching of linear transformations in Classes Préparatoires aux Grandes Écoles. The theory of didactical situations, jointly with Peirce’s semiotics, constitute the main theoretical framework of our works and allow us to analyse student’s reasoning in situations of oral evaluation. Firstly, we put forward some epistemological aspects highlighting the links between linear transformations and the emergence of linear algebra. Then, with a didactical objective, we outline the main features of Perice’s semiotics and its algebraization with the treillis of sign’s categories. Hence, we can enhance the model of analysis for reasoning processes of Bloch and Gibel and build a tool for semiotic analysis called semantic diagram. We illustrate the use of this tool by conducting a local semiotic a priori analysis of a mathematical situation. This analysis highlight the link between the first signs and actions of the situation and the resulting semiosis. Next, we analyse some students’ reasonings produced during oral evaluations said « classical ». This analysis confirms the link between the lack of an adidactical milieu and the semantic difficulty to organize and articulate the objects and signs in a proof situation. Then we experiment a situation of oral evaluation in which the adidactical milieus are rich enough and stabilized. The analysis of the reasoning process conducted in this experimental situation allows us to show that, in this case, the students rely on a semantic point of view on the objects to produce their validations and controls their productions. These three different moments of our research attest the importance of the heuristic practices and discourse in the field of linear algebra.

Developments in semiconductor and laser technologies have facilitated development of terahertz (THz)-frequency (˜2-200 cm-1) technologies. Results published in the literature as far back as the early 20th century demonstrate the utility of this frequency range for myriad applications, but the improved performance of modern THz technologies has renewed interest in THz-frequency analysis. Material presented in this dissertation focuses on three applications of terahertz time-domain spectroscopy (THz-TDS): quantitation of gas-phase molecular species, analysis of polymeric materials, and investigation of dental tissue/composite structures. Gas phase species were quantified individually at concentrations ranging from several parts per million to several parts per thousand using various chemometric methods. Quantitative model robustness was evaluated by comparison of model precision, and partial least-squares (PLS) regressions provided the greatest precision. Species were quantified in mixtures using PLS with errors of prediction below the permissible exposure limits (PELs) set by the Occupational Safety and Health Administration. The effect of spectral broadening as a result of overall sample pressure was investigated, and species were analyzed in mixtures at various overall pressures. Errors of prediction were again near or below the PELs, demonstrating the utility of this method for atmospheric analysis. Chemical selectivity available in THz spectral features was evaluated and compared to selectivity available in infrared frequencies. Spectral parameters measured in the THz frequency range also provide insight into structural properties of polymeric materials. In some cases, spectral peaks may be used to identify the temperature at which phase changes occur within these materials. THz refractive index spectra were found to be a sensitive and non-destructive tool for identification of phase transition temperatures. The time-resolved measurement of THz-TDS makes it particularly useful for rapid, non-destructive analysis of layered structures. Ordinarily, the strength of bonds between dental tissues and composite materials are evaluated in the laboratory using destructive failure analyses. Transparency of dental tissues and composite materials used for restorative procedures to THz pulses allows investigation of interfaces between these materials. Refractive index spectra indicate locations in which delamination has occurred between bonded layers. These results provide an overview of unique capabilities of the THz-TDS method in real-life spectral analyses.

筆記型電腦由於本身產品的生命週期短，技術淘汰率高、製程組裝不易、市場反應快速、原料價值變動大以及競爭性高的特性，客製化生產CTO (Configure To Order)生產模式成為筆記型電腦廠商的核心競爭能力，關係著未來的競爭優勢，因此我國各大筆記型電腦生產廠商莫不積極開發建立CTO生產模式。 　　研究者作為國內電子業廠商推動CTO工作的實務工作者，以1999年突破接單內兩天生產挑戰的個案公司為個案，在遵守商業倫理的必要限制下，以個人實際開創CTO生產流程之實務經驗敘述為主，撰寫研究報告，探討筆記型電腦產業CTO的生產流程作業，分析關鍵因素，據以提出生產管理與控制CTO的運作模式與建議，提供相關產業參考。 　　本研究主要研究目的分述如下： 　　　一、CTO生產模式之意義、功能與限制。 　　　二、探究CTO生產模式各流程之主要內涵。 　　　三、就個案公司實例分析CTO生產模式之關鍵因素。 　　　四、就個案公司之經驗，探討CTO生產模式台灣經驗移植至大陸的可行性與限制，提供建議與我國資訊產業實施參考。 　　討論部分，研究者針對政府ABCDE計畫對CTO生產模式的影響、OEM大廠對BTO/CTO的要求、CTO生產模式的構建成本與其所帶來附加價值以及CTO生產模式的應用範圍與移植大陸的可行性，做了詳盡的論述。最後研究者分別針對相關產業以及後續研究者提出建議，以供參考。 / Notebook computer is a short life, high technology, difficult assembly, fast marketing change, fluctuated material pricing and highly competed product. CTO (Configure To Order) manufacturing capability becomes Notebook PC manufacturers' core competence. All Taiwan Notebook PC manufacturers aggressively make a lot of efforts to build up CTO process capability. 　　The researcher has CTO process establishment experience. The established CTO process has achieved 2 days delivery after receipt of the orders. The researcher is willing to share his CTO process experience with public under business morality constraint. The analysis includes CTO process flow, the key success elements, CTO operation model and production control for associated industry's reference. 　　The purpose for this search is as follows: 　　　1). The meaning, function and limitation of CTO process. 　　　2). CTO process flow content 　　　3). CTO process key success elements 　　　4). The feasibility and constraint to transfer CTO process to China 　　With regard to the discussion that covers several areas: 1) How did government “ABCDE” project affect CTO process? 2) Major OEM customers' such as Compaq & Dell requirement in terms of BTO/CTO process, 3) The cost to build up CTO process and the added value CTO process may generate, 4) The suitable products to use CTO process and the feasibility to transfer CTO process to China. At last, the researcher made some suggestion to the associated industry and the follow-up researchers.

In this thesis, we describe the development of a time-domain terahertz (THz) spectrometer driven by two different laser sources: an Er-doped femtosecond fiber laser and a mode-locked Ti:Sapphire laser. The resulting THz electromagnetic radiation was generated and detected using photoconductive antenna detection methods in both systems. In these experiments we characterized the THz power output for both the fiber laser driven system and the Ti:Sapphire laser driven system. Emphasis is given throughout this thesis on understanding the working principles behind time-domain terahertz spectroscopy, applications of THz radiation and terahertz generation as well as terahertz detection methods. We calculated the THz power output using two different methods. By using the &ldquo / Hertzian Dipole&rdquo / method we estimated the generated THz power after the generation photoconductive antenna. Using this method, we showed that the v generated power is on the order of milliwatts, which is far larger than the expected power typical for these systems. The second, &ldquo / Open-Circuit Voltage&rdquo / method, allowed us to calculate the received power on the detection photoconductive antenna. Using this method we were able to show that the THz power generated and detected in these systems is on the order of microwatts. For the mode-locked fiber laser driven spectrometer we obtained on average a ~ 4 ps (0.25 THz) pulse length which corresponded to an average power in the range of 71.8 nW - 70.54 &amp / #956 / W on a dipole antenna with a 6 &amp / #956 / m dipole gap and 44 &amp / #956 / m dipole length. Using the mode-locked Ti:Sapphire laser driven spectrometer we observed a ~ 2 ps (0.5 THz) pulse length and average power in the range of 0.54 nW &ndash / 5.12 &amp / #956 / W on a different dipole antenna with a 5 &amp / #956 / m gap and 40 &amp / #956 / m dipole length. Since these values agree with expected values for these systems we believe the &ldquo / Open-Circuit Voltage&rdquo / method is appropriate when trying to calculate the THz power.

This thesis is on the topic of investigation of the characteristics of DC Glow Discharge plasmas. Emphasis is given on characterizing the plasma electron density. The methods of generating and detecting THz pulses are described. THz transmission spectroscopy and plasma emission spectroscopy is examined. Transmission spectrum is taken for Air, gaseous Nitrogen and Argon plasmas. Moreover, emission spectrum of Air, N2 and Ar plasma analysis were done respectively. It was found that the transmission of terahertz pulses through nitrogen plasma was considerably affected compared to that of the argon plasma. Initially Drude model theory of electron conduction is employed to analyze the plasma density.