Etude de circuits hyperfréquencés en utilisant la jonction inhomogène ligne à fente - ligne microruban. Application à l'interaction de filtres et de iplexeurs.

L'étude comporte quatre chapitres. Le premier permet de situer le sujet par rapport à la problématique de la miniaturisation des circuits électroniques dans le domaine des télécommunications hyperfréquences et d'exposer le cadre technologique de l'étude. L'association verticale des deux types de guidage (ligne microruban, ligne à fente) exploitée dans les chapitres suivants est abordée. Le deuxième chapitre est consacré à la modélisation des transitions entre ces deux types de lignes de transmission. La notion de jonction inhomogène permettant d'ajuster la bande passante de la transition est ainsi étudiée. La relation entre bande passante de la jonction et dimensionnement technologique des stubs est développée. Le troisième chapitre traite de la mise en oeuvre de méthode d'optimisation pour la conception de structures multicouches utilisant des jonctions inhomogènes. Une approche technologique des structures filtrantes est proposée et les outils logiciels d'aide à la conception développés dans le cadre d'une optimisation par la méthode des plans d'expérience sont présentés. Les performances du modèle proposé sont comparées à celles d'autres modèles ainsi qu'aux résultats disponibles dans la littérature. Enfin dans un dernier chapitre, des applications utilisant la jonction inhomogène permettent de valider les outils d'optimisation et de simulation développés. L'auteur traite successivement de la réalisation sur substrat d'alumine d'un filtre passe-bande (10-12GHz) puis développe plusieurs topologies de diplexeurs (voie basse : 8 - 10,8GHz et voie basse 11,2 - 14GHz). Les performances des circuits réalisés, en accord avec les spécifications initiales, permettent de valider l'approche de conception et d'optimisation. Pour finir une prospective en terme de filtre ajustable est suggérée.Four chapters compose this study. The first one situates the research subject into the high frequencies telecommunications domain with the links to the increasing of electronic circuits miniaturisation and the technological features used in the study. The vertical association of two types of wave guide lines (microstrip line and slot line) used in the following chapters is presented. The second chapter deals with the model of microstrip to slot line transition. This study is completed by a new inhomogeneous junction concept with tuneable bandwidth. The relationship between junction's bandwidth and technological dimensions of its stubs is developed. In the third chapter, an optimisation method for multi layer structures using inhomogeneous junction is developed. A technological approach of filtering structures is proposed and CAD (circuit aided design) tools based on DOE (design of experiment) optimisation method are presented. The model performances are compared to other models and literature results. Finally in a last chapter, structures using the inhomogeneous junctions validate the previous optimisation and simulation tools. The author treats successively several realisations on an alumina substrate: a band pass filter (10 - 12GHz) and several diplexer topologies (low frequencies way: 8 - 10.8GHz and high frequencies way: 11.2 - 14GHz). The features of these realisations, in conformity with the required specifications, validate the conception and optimisation approach. Finally, an expectation in terms of tuneable filter is planned

Assessing the ABL 500 blood gas analyser

The ABL 500 blood gas analyser from Radiometer has cordless electrodes and does not use a humidifier for calibrating gases. During the evaluation of the analytical performance of this instrument, the problem of p02 accuracy was approached by comparing the values obtained with two kinds of tonometry (film and bubble). An acceptable level of imprecision was demonstrated for all measured parameters. For within-run precision, with tonometry, coefficients of variation (CV) were ≆0.37% for pO2 and ≆0.52% for pCO2. A CV of 1.76% was found for day-to-day precision for both p02 and pCO2. In the linearity study, with both tonometry methods, and in the inter-instrument comparisons (the ABL was compared with the Ciba Corning 178), pO2 values obtained on the ABL 500 exhibited a slight overestimation above 150 mmHg (2.2-3.4% at 600 mmHg). This minor discrepancy is discussed with reference to the new design of the pO2 electrode, the algorithm for pO2 correction and the tonometry procedure. The results reported in this paper stress the importance of pO2 accuracy assessment for the evaluation of blood gas analysers

La nature comme principe dans le Traité des sensations de Condillac : des premiers motifs de l’analyse à la constitution des corps

Le Traité des sensations de Condillac, à travers la fiction d’une statue constituée comme nous dont on activerait successivement les sens, doit manifester la genèse de toutes nos facultés et connaissances à partir de la seule sensation qui se transforme différemment. Or, cette genèse semble s’adosser à une nature, comprise comme la conformation de nos organes, fournissant à la fois un moteur et un ordre à cet apprentissage. Cette notion de nature semble ainsi constituer un résidu d’innéité au cœur de l’entreprise génétique radicale de Condillac

Quelles sont les représentations des femmes enceintes de l'arrière-pays niçois concernant la coordination des soins de leur suivi de grossesse ?

Introduction : <br>Depuis 2007, la HAS préconise le suivi de la grossesse normale par une sage-femme et/ou un médecin généraliste. Sur le terrain, le suivi reste majoritairement assuré par les gynécologues-obstétriciens. Pour explorer cet écart aux recommandations, cette étude a choisi d’étudier un territoire fragile en démographie de soins. L’objectif principal était d’explorer les représentations des femmes enceintes de l'arrière-pays niçois concernant la coordination des soins de leur suivi de grossesse. L’objectif secondaire était d’identifier la place du carnet de maternité dans ces représentations.Méthodes : <br>Une étude qualitative exploratoire a été réalisée par entretiens semi-dirigés individuels en 2014 et 2015 auprès de femmes ayant mené leur grossesse dans l’arrière-pays niçois. Les entretiens ont été filmés, retranscrits verbatim et analysés par théorisation ancrée approchée à l’aide du logiciel Nvivo®. <br>Résultats : <br>Un échantillon varié de 12 femmes a permis la saturation théorique des données. Parmi elles, 75% étaient suivies par un gynécologue-obstétricien, 25% par une sage-femme. Les principaux critères de choix du professionnel étaient : compétence, disponibilité et confiance. Les femmes étaient majoritairement satisfaites de leur suivi de grossesse et envisageaient le même suivi en cas de grossesse ultérieure. Elles regrettaient le manque d’information sur les structures existant localement. Les femmes ne se sentaient pas concernées par la communication entre les professionnels et faisaient souvent l'intermédiaire car un support écrit était rarement utilisé. Le médecin généraliste était insuffisamment impliqué dans le suivi de grossesse du fait de la pudeur des femmes et de leur méconnaissance en ses capacités à suivre les grossesses. <br>Conclusion : <br>Notre étude confirme l’écart aux recommandations et suggère que cela convient aux femmes des territoires étudiés malgré une ambivalence entre un désir de suivi de grossesse de proximité et une surveillance échographique régulière

Microborings in mid Cretaceous fish teeth

Fish teeth and other remains from the British Cretaceous contain abundant evidence for post-mortem colonization by endolithic organisms. The borings are here recognised as occurring in three morphotypes, including a flask-shaped form not previously recorded. There is strong evidence to suggest that each of these boring types shows a strong preference for a particular substrate histology. The damage and destruction of vertebrate remains by microborings is here considered to exert a major taphonomic control on microvertebrate assemblages. The relationships between the intensity of colonization of vertebrate material by endolithic organisms and palaeoenvironment have implications for using these bone microborings as palaeoenvironmental indicators

Achieving privacy and accountability in traceable digital currency

Several Central Bank Digital Currency (CBDC) projects are considering the development of a digital currency that is managed on a permissioned blockchain, i.e. only authorized entities are involved in transactions verification. In this paper, we explore the best possible balance between privacy and accountability in such a traceable digital currency. Indeed, in case of suspicion of fraud or money laundering activity, it is important to enable the retrieval of the identity of a payer or a payee involved in a specific transaction. Based on a preliminary analysis of achievable anonymity properties in a transferable, divisible and traceable digital currency systems, we first present a digital currency framework along with the corresponding security and privacy model. Then, we propose a pairing-free traceable digital currency system that reconciles user\u27s privacy protection and accountability. Our system is proven secure in the random oracle model

Impacto dos acordos comerciais do Brasil : aplicação do modelo gravitacional

Tese (doutorado)—Universidade de Brasília, Departamento de Economia, Brasília, 2017.Com o rápido crescimento no número de acordos comerciais a partir da década de 1990, surge a necessidade de ferramentas que permitissem avaliar os impactos econômicos e comerciais desses acordos. Para suprir essa necessidade, desenvolve-se uma ampla literatura de métodos de avaliação de impactos de acordos comerciais. Ao revisar a aplicação desses métodos para o caso brasileiro, percebe-se uma concentração de trabalhos que procuraram investigar os efeitos da criação do Mercosul para a economia brasileira. Todavia, um exame dos acordos comerciais do Brasil mostra que, atualmente, estão em vigor acordos de livre comércio com sete países, além daqueles que originalmente integram o Mercosul: Chile, Bolívia, Peru, Colômbia, Equador, Venezuela e Israel. O objetivo desse trabalho será, portanto, avaliar os efeitos de criação e o desvio de comércio dos acordos do Brasil com cada um desses sete países. Para tanto, revisamos a literatura sobre avaliação de acordos comerciais e verificamos que o modelo gravitacional é a ferramenta mais utilizada para avaliações ex post. Em seguida, aprofundamos a teoria que embasa o modelo gravitacional e as questões metodológicas para sua aplicação a fim de identificar o melhor método para estimação da equação gravitacional. Os resultados mostraram que, no caso de Peru e Colômbia, houve criação de comércio, enquanto que, para Chile, Bolívia e Colômbia, houve desvio de comércio. Para os demais casos, os coeficientes estimados não foram significativos, não permitindo identificar criação ou desvio de comércio. Conclui-se, portanto, que nem todos os acordos assinados pelo Brasil surtiram efeito sobre os fluxos comerciais bilaterais.With the rapid growth in the number of trade agreements since the 1990s, emerges the need for tools to assess the economic and trade impacts of these agreements. To address this necessity, a broad literature on methods of assessing the impact of trade agreements is developed. When reviewing the application of these methods to the Brazilian case, a concentration of works that sought to investigate the effects of the creation of Mercosur for the Brazilian economy is noticed. However, Brazil currently has free trade agreements with seven countries, in addition to those in Mercosur: Chile, Bolivia, Peru, Colombia, Ecuador, Venezuela and Israel. The aim of the present work is to evaluate the effects of trade creation and trade diversion resulting from the aforementioned agreements. In order to do so, we review the literature on the impact assessment of trade agreements and verify that the gravity model is the most used tool for ex post evaluations. Next, we deepen the theory that bases the gravitational model and the methodological questions for its application in order to identify the best method for estimation of the gravity equation. The results showed that, in the case of Peru and Colombia, there was trade creation, while for Chile, Bolivia and Colombia there was trade diversion. For the remaining cases, since the estimated coefficients were not significant, it was not possible to identify trade creation or trade diversion. Therefore, the conclusion is that not all agreements signed by Brazil have had an effect on bilateral trade flows

Artificial intelligence and thyroid disease management: considerations for thyroid function tests

Artificial intelligence (AI) is transforming healthcare and offers new tools in clinical research, personalized medicine, and medical diagnostics. Thyroid function tests represent an important asset for physicians in the diagnosis and monitoring of pathologies. Artificial intelligence tools can clearly assist physicians and specialists in laboratory medicine to optimize test prescription, tests interpretation, decision making, process optimization, and assay design. Our article is reviewing several of these aspects. As thyroid AI models rely on large data sets, which often requires distributed learning from multi-center contributions, this article also briefly discusses this issue