39 research outputs found
Étude de filtres hyperfréquence SIW et hybride-planaire SIW en technologie LTCC
La maîtrise de la communication et de l'information est un atout primordial dans les stratégies de pouvoir, qu'elles soient militaires, politiques ou commerciales. Celui qui est capable de transmettre l'information plus vite prend l'avantage sur les autres. Tel est le moteur de la croissance et du progrès dans le domaine des télécommunications. L'omniprésence grandissante des dispositifs communicants témoigne de l'expansion exponentielle qu'a connu ce domaine depuis les premières communications sans fil. À l'époque du all-in-one, la multiplication des applications au sein d'un même appareil nécessite l'utilisation de composants toujours plus performants et petits . Au cœur de ces systèmes, les filtres ont une importance grandissante. Dans un environnement spatial, les contraintes de fiabilité et d'encombrement sont particulièrement drastiques. Le choix des matériaux est par ailleurs limité, ce qui réduit les possibilités d'innovation. Cependant, l'amélioration de la précision et de la fiabilité dans les technologies de fabrication ouvre de nouvelles perspectives d'innovation et d'amélioration des composants. Ces travaux ont ainsi été motivés par ce souci d'apporter toujours plus de performance et de fiabilité, pour un encombrement moindre en tirant profit du potentiel offert par l'association du concept SIW et de la technologie LTCC. Les résultats mettent à jour de sérieuses dispersions technologiques. Cependant, le potentiel de l'association SIW/LTCC est démontré, et les difficultés rencontrées sont surmontables. Les filtres SIW en technologie LTCC présentent donc des atouts pour s'imposer comme une alternative sérieuse aux solutions existantes.Control of communication and information is a key asset in the strategies of power, whether military, political or commercial. Whoever is able to transmit information faster takes advantage of others. This is the engine of growth and progress in the field of telecommunications. The growing ubiquity of communicating devices demonstrates the exponential growth experienced by this area since the first wireless communications. At the time of all-in-one, multiple applications within a single device requires the use of ever more powerful and small components. At the heart of these systems, filters are becoming increasingly important. In a space environment, reliability constraints and space are particularly dramatic. The choice of materials is also limited, which reduces the possibilities of innovation. However, the improvement of accuracy and reliability in manufacturing technologies opens new opportunities for innovation and improved components. This work has been motivated by the desire to bring more performances and reliability, a smaller footprint by taking advantage of the potential offered by combining the concept SIW and LTCC. The results update serious technological dispersions. However, the potential association SIW / LTCC is shown, and the difficulties are surmountable. SIW filters in LTCC therefore have advantages for itself as a serious alternative to existing solutions.BREST-SCD-Bib. electronique (290199901) / SudocSudocFranceF
Étude d'un filtre volumique SIW en technologie LTCC sur un substrat de forte permittivité en bande X
National audienceLa technologie SIW apporte un gain en terme de facteur de qualité par rapport aux technologies planaires. Sa facilité d'intégration avec ces dernières, ainsi que son coût de production sont autant d'atouts qui la rendent attractive. Son encombrement reste en revanche l'un de ses principal défaut. Ce document présente ici la combinaison de deux solutions pour y remédier : L'utilisation d'une technologie multicouche pour empiler les cavités et réduire ainsi l'empreinte. L'utilisation d'un substrat de haute permittivité afin de réduire les dimensions selon les 3 axes. Ces solutions sont testées ici sur un filtre d'ordre 6 en bande X
Design of hybrid-planar SIW High frequency filter in LTCC Technology
La maîtrise de la communication et de l'information est un atout primordial dans les stratégies de pouvoir, qu'elles soient militaires, politiques ou commerciales. Celui qui est capable de transmettre l'information plus vite prend l'avantage sur les autres. Tel est le moteur de la croissance et du progrès dans le domaine des télécommunications. L'omniprésence grandissante des dispositifs communicants témoigne de l'expansion exponentielle qu'a connu ce domaine depuis les premières communications sans fil. À l'époque du all-in-one, la multiplication des applications au sein d'un même appareil nécessite l'utilisation de composants toujours plus performants et petits . Au cœur de ces systèmes, les filtres ont une importance grandissante. Dans un environnement spatial, les contraintes de fiabilité et d'encombrement sont particulièrement drastiques. Le choix des matériaux est par ailleurs limité, ce qui réduit les possibilités d'innovation. Cependant, l'amélioration de la précision et de la fiabilité dans les technologies de fabrication ouvre de nouvelles perspectives d'innovation et d'amélioration des composants. Ces travaux ont ainsi été motivés par ce souci d'apporter toujours plus de performance et de fiabilité, pour un encombrement moindre en tirant profit du potentiel offert par l'association du concept SIW et de la technologie LTCC. Les résultats mettent à jour de sérieuses dispersions technologiques. Cependant, le potentiel de l'association SIW/LTCC est démontré, et les difficultés rencontrées sont surmontables. Les filtres SIW en technologie LTCC présentent donc des atouts pour s'imposer comme une alternative sérieuse aux solutions existantes.Control of communication and information is a key asset in the strategies of power, whether military, political or commercial. Whoever is able to transmit information faster takes advantage of others. This is the engine of growth and progress in the field of telecommunications. The growing ubiquity of communicating devices demonstrates the exponential growth experienced by this area since the first wireless communications. At the time of all-in-one, multiple applications within a single device requires the use of ever more powerful and small components. At the heart of these systems, filters are becoming increasingly important. In a space environment, reliability constraints and space are particularly dramatic. The choice of materials is also limited, which reduces the possibilities of innovation. However, the improvement of accuracy and reliability in manufacturing technologies opens new opportunities for innovation and improved components. This work has been motivated by the desire to bring more performances and reliability, a smaller footprint by taking advantage of the potential offered by combining the concept SIW and LTCC. The results update serious technological dispersions. However, the potential association SIW / LTCC is shown, and the difficulties are surmountable. SIW filters in LTCC therefore have advantages for itself as a serious alternative to existing solutions
Étude de filtres hyperfréquence SIW et hybride-planaire SIW en technologie LTCC
Control of communication and information is a key asset in the strategies of power, whether military, political or commercial. Whoever is able to transmit information faster takes advantage of others. This is the engine of growth and progress in the field of telecommunications. The growing ubiquity of communicating devices demonstrates the exponential growth experienced by this area since the first wireless communications. At the time of all-in-one, multiple applications within a single device requires the use of ever more powerful and small components. At the heart of these systems, filters are becoming increasingly important. In a space environment, reliability constraints and space are particularly dramatic. The choice of materials is also limited, which reduces the possibilities of innovation. However, the improvement of accuracy and reliability in manufacturing technologies opens new opportunities for innovation and improved components. This work has been motivated by the desire to bring more performances and reliability, a smaller footprint by taking advantage of the potential offered by combining the concept SIW and LTCC. The results update serious technological dispersions. However, the potential association SIW / LTCC is shown, and the difficulties are surmountable. SIW filters in LTCC therefore have advantages for itself as a serious alternative to existing solutions.La maîtrise de la communication et de l'information est un atout primordial dans les stratégies de pouvoir, qu'elles soient militaires, politiques ou commerciales. Celui qui est capable de transmettre l'information plus vite prend l'avantage sur les autres. Tel est le moteur de la croissance et du progrès dans le domaine des télécommunications. L'omniprésence grandissante des dispositifs communicants témoigne de l'expansion exponentielle qu'a connu ce domaine depuis les premières communications sans fil. À l'époque du all-in-one, la multiplication des applications au sein d'un même appareil nécessite l'utilisation de composants toujours plus performants et petits . Au cœur de ces systèmes, les filtres ont une importance grandissante. Dans un environnement spatial, les contraintes de fiabilité et d'encombrement sont particulièrement drastiques. Le choix des matériaux est par ailleurs limité, ce qui réduit les possibilités d'innovation. Cependant, l'amélioration de la précision et de la fiabilité dans les technologies de fabrication ouvre de nouvelles perspectives d'innovation et d'amélioration des composants. Ces travaux ont ainsi été motivés par ce souci d'apporter toujours plus de performance et de fiabilité, pour un encombrement moindre en tirant profit du potentiel offert par l'association du concept SIW et de la technologie LTCC. Les résultats mettent à jour de sérieuses dispersions technologiques. Cependant, le potentiel de l'association SIW/LTCC est démontré, et les difficultés rencontrées sont surmontables. Les filtres SIW en technologie LTCC présentent donc des atouts pour s'imposer comme une alternative sérieuse aux solutions existantes
Analysis of specific water masses transports in the Western Mediterranean in the MEDRYS1V2 twenty-one-year reanalysis
We present an analysis of specific water masses fluxes in the Western Mediterranean Sea issued from a twenty years (1992-2013) reanalysis (MEDRYS1V2). Water masses are identified on the base of salinity and potential density properties and computes; the fractions of each water mass involved in total flux are computed under the hypothesis assumptions of mixing lines schemes. It was first designed in order to avoid rough truncations between water masses on the T-S diagram when using fixed thermo-haline properties thresholds. The method does not use the temperature marker due to its high seasonal variability in near surface waters (0-200 m) and we consider that potential density is a better marker to discriminate deep and intermediate water masses. The algorithm discriminates successively five different water masses : the Atlantic Water (AW) incoming from the Gibraltar strait (salinity between 36,1 and 38,45 PSU), the Levantine Intermediate Waters (LIW) incoming from the Tunisia-Sicily strait (salinity between 38,45 and 39.1 PSU), the Modified Atlantic Waters (MAW) defined as near-surface waters (potential density less than 28,9 kg m-3) that are neither AW or LIW, while Western Intermediate Waters (WIW) are those remaining until the σθ = 29,10 kg m-3 threshold for Western Mediterranean Deep Waters (WMDW) is reached. Such computed fractions of each water mass, whose sum is constrained to unity, are then used to compute their water masses transports all along over twenty years of the reanalysis. The transport are assessed across computed on key transects delimiting known sub-basin entities (Ligurian Sea, Gulf of Lion, Balearic Sea...), with total transports showing balanced mass budget. The such computed total transport reveal marked differences in their seasonal to interannual variability, while the analysis of the water mass transports allows to identify those which mainly implied induced these variability. The results first show a low seasonal and no significant interannual variability at the exit of the Alboran Sea that results from the balance between the eastward AW/MAW outflow and the westward WIW and WMDW inflows. The Corsican strait, the Ligurian Sea line and Tunisia-Sardinia straits show a marked seasonal variability (0,37-0,39 Sv) mainly driven by the AW/MAW. By contrast, a strong interannual variability dominates the seasonal one (-2 to 1 Sv) between the Algerian Basin and the northern basin, correlated to the WMDW formation. The analysis of each specific water masses transport pointed out that shows this marked variability to be first driven by the intermediate and deep water masses transports. Similarly the interannual variability of the AW and MAW transports in the central part of the Western Mediterranean suggests some coupling between the deep, intermediate and surface water masses, even through the shallower Balearic Sea
Analyse des transports spécifiques des masses d'eau en Méditerranée occidentale dans la réanalyse de vingt et un ans de MEDRYS1V2.
International audienceWe present an analysis of specific water masses fluxes in the Western Mediterranean Sea issued from a twenty years (1992-2013) reanalysis (MEDRYS1V2). Water masses are identified on the base of salinity and potential density properties and computes; the fractions of each water mass involved in total flux are computed under the hypothesis assumptions of mixing lines schemes. It was first designed in order to avoid rough truncations between water masses on the T-S diagram when using fixed thermo-haline properties thresholds. The method does not use the temperature marker due to its high seasonal variability in near surface waters (0-200 m) and we consider that potential density is a better marker to discriminate deep and intermediate water masses. The algorithm discriminates successively five different water masses : the Atlantic Water (AW) incoming from the Gibraltar strait (salinity between 36,1 and 38,45 PSU), the Levantine Intermediate Waters (LIW) incoming from the Tunisia-Sicily strait (salinity between 38,45 and 39.1 PSU), the Modified Atlantic Waters (MAW) defined as near-surface waters (potential density less than 28,9 kg m-3) that are neither AW or LIW, while Western Intermediate Waters (WIW) are those remaining until the sigma(theta) = 29,10 kg m-3 threshold for Western Mediterranean Deep Waters (WMDW) is reached. Such computed fractions of each water mass, whose sum is constrained to unity, are then used to compute their water masses transports all along over twenty years of the reanalysis. The transport are assessed across computed on key transects delimiting known sub-basin entities (Ligurian Sea, Gulf of Lion, Balearic Sea...), with total transports showing balanced mass budget. The such computed total transport reveal marked differences in their seasonal to interannual variability, while the analysis of the water mass transports allows to identify those which mainly implied induced these variability. The results first show a low seasonal and no significant interannual variability at the exit of the Alboran Sea that results from the balance between the eastward AW/MAW outflow and the westward WIW and WMDW inflows. The Corsican strait, the Ligurian Sea line and Tunisia-Sardinia straits show a marked seasonal variability (0,37-0,39 Sv) mainly driven by the AW/MAW. By contrast, a strong interannual variability dominates the seasonal one (-2 to 1 Sv) between the Algerian Basin and the northern basin, correlated to the WMDW formation. The analysis of each specific water masses transport pointed out that shows this marked variability to be first driven by the intermediate and deep water masses transports. Similarly the interannual variability of the AW and MAW transports in the central part of the Western Mediterranean suggests some coupling between the deep, intermediate and surface water masses, even through the shallower Balearic Sea.Nous présentons une analyse des flux de masses d'eau spécifiques dans la mer Méditerranée occidentale issus d'une réanalyse sur vingt ans (1992-2013) (MEDRYS1V2). Les masses d'eau sont identifiées sur la base des propriétés de salinité et de densité potentielle et calculées ; les fractions de chaque masse d'eau impliquées dans le flux total sont calculées sous les hypothèses des schémas de lignes de mélange. Cette méthode a été initialement conçue pour éviter les troncatures grossières entre les masses d'eau sur le diagramme T-S lors de l'utilisation de seuils fixes de propriétés thermo-halines. La méthode n'utilise pas le marqueur de température en raison de sa grande variabilité saisonnière dans les eaux proches de la surface (0-200 m) et nous considérons que la densité potentielle est un meilleur marqueur pour discriminer les masses d'eau profondes et intermédiaires. L'algorithme discrimine successivement cinq masses d'eau différentes : les eaux atlantiques (AW) provenant du détroit de Gibraltar (salinité entre 36,1 et 38,45 PSU), les eaux intermédiaires du Levant (LIW) provenant du détroit de Tunisie-Sicile (salinité entre 38,45 et 39. 1 PSU), les eaux atlantiques modifiées (MAW) définies comme des eaux proches de la surface (densité potentielle inférieure à 28,9 kg m-3) qui ne sont ni AW ni LIW, tandis que les eaux intermédiaires occidentales (WIW) sont celles qui restent jusqu'à ce que le seuil sigma(theta) = 29,10 kg m-3 pour les eaux profondes de la Méditerranée occidentale (WMDW) soit atteint. Ces fractions calculées de chaque masse d'eau, dont la somme est contrainte à l'unité, sont ensuite utilisées pour calculer les transports de leurs masses d'eau tout au long des vingt années de la réanalyse. Les transports sont évalués à travers les calculs sur des transects clés délimitant des entités de sous-bassins connues (mer Ligure, golfe du Lion, mer Baléares...), avec des transports totaux montrant un bilan de masse équilibré. Les transports totaux ainsi calculés révèlent des différences marquées dans leur variabilité saisonnière et inter-annuelle, tandis que l'analyse des transports de masse d'eau permet d'identifier ceux qui ont principalement induit cette variabilité. Les résultats montrent d'abord une faible variabilité saisonnière et une variabilité inter-annuelle non significative à la sortie de la mer d'Alboran qui résulte de l'équilibre entre le flux sortant AW/MAW vers l'est et les flux entrants WIW et WMDW vers l'ouest. Le détroit de Corse, la ligne de la mer Ligure et les détroits de Tunisie et de Sardaigne présentent une variabilité saisonnière marquée (0,37-0,39 Sv) principalement due à l'AW/MAW. En revanche, une forte variabilité inter-annuelle domine la variabilité saisonnière (-2 à 1 Sv) entre le bassin algérien et le bassin nord, corrélée à la formation de l'WMDW. L'analyse de chaque transport spécifique de masses d'eau a montré que cette variabilité marquée est d'abord déterminée par les transports de masses d'eau intermédiaires et profondes. De même, la variabilité inter-annuelle des transports AW et MAW dans la partie centrale de la Méditerranée occidentale suggère un certain couplage entre les masses d'eau profondes, intermédiaires et de surface, même à travers la mer des Baléares, moins profonde
SHAPE: A temporal optimization model for residential buildings retrofit to discuss policy objectives
International audienceIn a context of massive renovation of residential buildings, stakeholders need decision-support models based on knowledge of the current building stock and accurate simulation of energy demand. This paper presents a new strategy for reducing energy consumption in the building sector, a key factor in combating climate change and promoting sustainability. We introduce an approach to (1) plan retrofits at community level, with a building resolution, for different years of an optimization period and (2) assist local authorities in selecting effective measures to improve the environmental performance of their building stock. The focus is on creating trajectory retrofit plans creation for a building stock with three main retrofit options: improving insulation, heating systems and hot water systems. We adapt a complex but linear approach, a type of problem-solving structure known as a multidimensional multiple-choice knapsack problem, which manages to handle a large number of possible retrofit combinations without becoming unwieldy. The planning process is streamlined as a single-objective optimization task that aims to reduce the total cost of retrofits by reducing their net present value.The efficiency of the model is demonstrated by simulating retrofit scenarios for 4,000 buildings in a French region to prove its ability to tackle large problems. France’s targets for decarbonizing the residential sector are taken into account, with a target of reducing GHG emissions by a factor of 10 and a building stock consuming 80kWhEP/m2/year. The results show that these plans are feasible, but that they will require 50% of all buildings to undergo major renovation with abatement costs of around €200/tGES. Our practical application to an actual community demonstrates the model’s ability to identify appropriate retrofitting measures and compile building data
VACUMM - A Python Library for Ocean Science
VACUMM is an open-source Python library for processing data from observations and numerical models. The library is now used for several years in
research and operational contexts, for instance for producing fi gures and reports, validating models, converting data, or making simple or advanced
diagnostics. In this paper, we introduce how the library is built, and we present two applications of its use: one in an operational context and one in a
research context
Characterization of fronts in the Western Mediterranean with a special focus on the North Balearic Front
We focus on the characterization of thermohaline fronts in the Western Mediterranean, with a particular focus on the North Balearic Front (NBF), separating the Atlantic Waters that spread into the Algerian Basin from the saltier and colder waters of the Liguro-Provençal area. We use a simple gradient-based method of front detection applied to a 20-year (from June 1993 to June 2013) reanalysis of the Mediterranean. Statistics of daily frontal indices are used to identify areas of recurrent fronts, i.e., frontal zones. Comparisons with data from glider transects and remotely sensed sea surface temperature and altimetry data have been used to validate our approach from daily to seasonal and interannual time scales. Our method yielded two co-existing frontal zones in the area of the NBF. One with an almost permanent haline surface frontal zone extending southeastward from the Balearic Islands to Sardinia, representing the northern limit of the fresher Atlantic Water that spreads via instabilities of the Algerian Current and associated Algerian Eddies. Between years, its position shifts by about 1° of latitude, possibly due to processes associated with both the deep water formation in the Provençal Basin and the spreading of southern Algerian Eddies. The second frontal zone is seasonal and thermally driven extending off the northeast of Menorca to the northwest of Corsica. The Pyrenees Front, a sharp thermal front off Cap de Creus which marks the boundary between the warm surface waters of the Balearic Sea and the cooler waters in the Gulf of Lion in late summer, appears to facilitate the formation of the aforementioned seasonal thermal front through the northeastward advection of its waters toward the West Corsican Current. The divergent eastward extensions of the two frontal zones, and their differences in nature, structure, and spatio-temporal variability, call for a revisit of the NBF appellation and a clarification of its dynamics