Kinematic analysis of complex gear mechanisms

This paper presents a general kinematic analysis method for complex gear mechanisms. This approach involves the null-space of the adjacency matrix associated with the graph of the mechanism weighted by complex coecients. It allows to compute the rotational speed ratios of all the links and the frequency of all the contacts in this mechanism(including roll bearings). This approach is applied to various examples including a two degrees of freedom car differential

Frequency of pattern occurrences in Motzkind words

In this work we show that the number of horizontal steps in a Motzkin word of length n, drawn at random under uniform distribution, has a Gaussian limit distribution. We also prove a local limit property for the same random variable which stresses its periodic behaviour. Similar results are obtained for the number of peaks in a word of given length drawn at random from the same language

Philosophie en pièces(s) : la poétique métaphysique dans Axël de Villiers de l’Isle-Adam

Si Platon a souvent été très critique à l’égard du théâtre et de la littérature en général, reprochant aux poètes d’introduire « un mauvais génie dans l’âme de chacun », le genre dramatique va revêtir, au XIXe siècle, une dimension philosophique nouvelle. À l’heure de la comédie de boulevard et de la « pièce bien faite », un théâtre d’idées commence à émerger et Villiers de l’Isle-Adam fait figure de précurseur de ce nouveau théâtre. Sa pièce Axël s’est rapidement imposée comme l’œuvre matricielle du drame symboliste. Dans ce mémoire, il s’agit d’étudier le caractère philosophique d’Axël, pièce publiée à titre posthume en 1891, et les procédés dramaturgiques employés par l’auteur pour revitaliser un genre littéraire qu’il jugeait lui-même en décrépitude. Dans ce travail, nous repérons les fragments des théories idéalistes de Hegel et Schopenhauer que Villiers réutilise dans sa pièce pour consacrer sa philosophie personnelle : l’illusionnisme. Nous nous intéressons aussi à la manière dont Villiers parvient, en renouvelant les canons de la dramaturgie classique, à insuffler le soupçon de vie nécessaire pour « faire d’une abstraction philosophique une réalité dramatique ». Finalement notre mémoire tend à vérifier l’hypothèse de Camille Dumoulié, exposée dans son essai Littérature et Philosophie, qui fait de la littérature l’Idée de la philosophie.If Plato often criticized theater and literature, faulting poets of “implanting an evil constitution in the soul of man”, theater dons, nonetheless, a new philosophical dimension in the 19th century. At a time of boulevard comedy and of “well-made play”, a theater of ideas begins to emerge. Villiers de l’Isle-Adam is a precursor of this new theater thanks to his play Axël, who quickly became the template of symbolist theater. In this thesis, we will study the philosophical features of this play, published posthumously in 1891, and the dramaturgical methods employed by the author to give a new life to this literary genre, which he himself considered as dying. In this work, we will find fragments and references to the idealist theories by Hegel and Schopenhauer, which Villiers used in his play to illustrate his personal philosophy: Illusionism. We will study the ways in which Villiers, by renewing the classical techniques of play writing, brings in the dialogues the new life necessary to “make of an abstract philosophy a tangible play”. Finally, this thesis, has a propensity to verify the hypothesis of Camille Dumoulié, exposed in his essay Littérature et Philosophie, which argues that literature is the idea of philosophy

Silicon dry oxidation kinetics at low temperature in the nanometric range: Modeling and experiment

Kinetics of silicon dry oxidation are investigated theoretically and experimentally at low temperature in the nanometer range where the limits of the Deal and Grove model becomes critical. Based on a fine control of the oxidation process conditions, experiments allow the investigation of the growth kinetics of nanometric oxide layer. The theoretical model is formulated using a reaction rate approach. In this framework, the oxide thickness is estimated with the evolution of the various species during the reaction. Standard oxidation models and the reaction rate approach are confronted with these experiments. The interest of the reaction rate approach to improve silicon oxidation modeling in the nanometer range is clearly demonstrated

Palaeohydrological changes over the last 50 ky in the central Gulf of Cadiz: complex forcing mechanisms mixing multi-scale processes

New dinoflagellate cyst (dinocyst) analyses were carried out at high resolution in core MD99-2339, retrieved from a contouritic field in the central part of the Gulf of Cadiz, for the Marine Isotope Stage (MIS) 3 interval, allowing for discussion of palaeohydrological changes over the last 50 ky in the subtropical NE Atlantic Ocean. Some index dinocyst taxa, according to their (palaeo) ecological significance, shed light on significant sea-surface changes. Superimposed on the general decreasing pattern of dinocyst export to the seafloor over the last 50 ky, paralleling the general context of decreasing aeolian dust fertilization, a complex variability in dinocyst assemblages was detected at the millennial timescale. Enhanced fluvial discharges occurred during Greenland Interstadials (GIs), especially GI 1, 8 and 12, while enhanced upwelling cell dynamics were suggested during the Last Glacial Maximum and Heinrich Stadials. Finally, during the early Holocene, and more specifically during the Sapropel 1 interval (around 7-9 ka BP), we evidenced a strong decrease in dinocyst fluxes, which occurred synchronously to a strong reduction in Mediterranean Outflow Water strength and which we attributed to an advection of warm and nutrient-poor subtropical North Atlantic Central Waters. Over the last 50 ky, our study thus allows for capturing and documenting the fine tuning existing between terrestrial and marine realms in North Atlantic subtropical latitudes, in response to not only the regional climate pattern but also monsoonal forcing interfering during precession-driven Northern Hemisphere insolation maxima. This mechanism, well expressed during the Holocene, is superimposed on the pervasive role of the obliquity as a first major trigger for explaining migration of dinocyst productive centres in the NE Atlantic margin to the subtropical (temperate) latitudes during glacial (interglacial) periods

AGMIAL: implementing an annotation strategy for prokaryote genomes as a distributed system

We have implemented a genome annotation system for prokaryotes called AGMIAL. Our approach embodies a number of key principles. First, expert manual annotators are seen as a critical component of the overall system; user interfaces were cyclically refined to satisfy their needs. Second, the overall process should be orchestrated in terms of a global annotation strategy; this facilitates coordination between a team of annotators and automatic data analysis. Third, the annotation strategy should allow progressive and incremental annotation from a time when only a few draft contigs are available, to when a final finished assembly is produced. The overall architecture employed is modular and extensible, being based on the W3 standard Web services framework. Specialized modules interact with two independent core modules that are used to annotate, respectively, genomic and protein sequences. AGMIAL is currently being used by several INRA laboratories to analyze genomes of bacteria relevant to the food-processing industry, and is distributed under an open source license

Deglacial laminated facies on the NW European continental margin: The hydrographic significance of British-Irish Ice Sheet deglaciation and Fleuve Manche paleoriver discharges

[1] We have compiled results obtained from four high sedimentation rate hemipelagic sequences from the Celtic sector of the NW European margin ( NE Atlantic) to investigate the paleoceanographic and paleoclimatic evolution of the area over the last few climatic cycles. We focus on periods characteristic of deglacial transitions. We adopt a multiproxy sedimentological, geochemical, and micropaleontological approach, applying a sampling resolution down to ten microns for specific intervals. The investigation demonstrates the relationships between the Bay of Biscay hydrography and the glacial/deglacial history of both the proximal British-Irish Ice Sheet (BIIS) and the western European continent. We identify recurrent phases of laminae deposition concurrent with major BIIS deglacial episodes in all the studied cores. Evidence for abrupt freshwater discharges into the open ocean highlights the influence of such events at a regional scale. We discuss their impact at a global scale considering the present and past key location of the Bay of Biscay versus the Atlantic Meridional Overturning Circulation (AMOC)

Assessment of sea surface temperature changes in the Gulf of Cadiz during the last 30 ka: Implications for glacial changes in the regional hydrography

New dinocyst analyses were conducted on core MD99-2339 retrieved from the central Gulf of Cadiz. Dinocyst and foraminiferal assemblages from this core are combined with existing data off SW Portugal and NW Morocco to investigate past hydrological and primary productivity regimes in the subtropical NE Atlantic Ocean over the last 30 ka. Our results have revealed highest upwelling intensity during Heinrich Stadial 1 (HS 1) and the Younger Dryas and weaker upwelling cells during the Last Glacial Maximum (LGM) and HS 2, off the SW Iberian and NW Moroccan margins. Similar assemblages between the Gulf of Cadiz and the NW Moroccan margin, and distinct species off Portugal, were observed during the cold climatic extremes that punctuated the last 30 ka. This pattern has been linked to the occurrence of a hydrological structure between SW Iberia and Cadiz during the last glacial period, perhaps similar to the modern Azores Front. This front was probably responsible locally for heterotrophic dinocysts found in the Gulf of Cadiz during the last glacial period, even if this sector is not conductive to upwelling phenomena by Ekman transport. Regional reconstructions of paleo-sea-surface temperatures (SSTs) using dinocyst and foraminiferal transfer functions, as well as alkenones, are also discussed and depict coherent scenarios over the last 30 ka. Seasonal reconstructions Correspondence to: A. Penaud ([email protected].) of LGM SSTs obtained with this multi-proxy panel are discussed jointly with model outputs in order to contribute to ongoing efforts in model-data comparisonC2007-FCT/319/2006info:eu-repo/semantics/publishedVersio