2,937 research outputs found
Equicontinuous factors, proximality and Ellis semigroup for Delone sets
We discuss the application of various concepts from the theory of topological
dynamical systems to Delone sets and tilings. We consider in particular, the
maximal equicontinuous factor of a Delone dynamical system, the proximality
relation and the enveloping semigroup of such systems.Comment: 65 page
Application d'un "Leap Motion" Ă l'apprentissage de trajectoires
Le but de ce travail est de capturer les mouvements de la main au moyen d'un «Leap Motion Controller» et de reproduire ses gestes en direct ou en différé sur un bras robot TX60 de Stäubli
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Feature contingencies when reading letter strings.
Many models posit the use of distinctive spatial features to recognize letters of the alphabet, a fundamental component of reading. It has also been hypothesized that when letters are in close proximity, visual crowding may cause features to mislocalize between nearby letters, causing identification errors. Here, we took a data-driven approach to investigate these aspects of textual processing. Using data collected from subjects identifying each letter in thousands of lower-case letter trigrams presented in the peripheral visual field, we found characteristic error patterns in the results suggestive of the use of particular spatial features. Distinctive features were seldom entirely missed, and we found evidence for errors due to doubling, masking, and migration of features. Dependencies both amongst neighboring letters and in the responses revealed the contingent nature of processing letter strings, challenging the most basic models of reading that ignore either crowding or featural decomposition
Real-Time analysis and visualization for single-molecule based super-resolution microscopy
Accurate multidimensional localization of isolated fluorescent emitters is a time consuming process in single-molecule based super-resolution microscopy. We demonstrate a functional method for real-time reconstruction with automatic feedback control, without compromising the localization accuracy. Compatible with high frame rates of EM-CCD cameras, it relies on a wavelet segmentation algorithm, together with a mix of CPU/GPU implementation. A combination with Gaussian fitting allows direct access to 3D localization. Automatic feedback control ensures optimal molecule density throughout the acquisition process. With this method, we significantly improve the efficiency and feasibility of localization-based super-resolution microscopy
: Contextes, enjeux, objectifs
Synthèse issue d'un rapport de 264 pages remis au Conseil de Développement du Pays Asses, Verdon, Vaïre, Var (A3V) en février 2012Cette synthèse est issue du rapport produit par le CERAMAC au terme de deux années d'une recherche prospective, appliquée et participative, sous convention avec le Conseil de Développement du Pays A3V et en accord avec le Comité de Pays dans le cadre du contrat Pays / Région. Après un diagnostic des principales problématiques relatives à l'évolution des espaces de ces vallées des Alpes du Sud, ce document présente les enjeux majeurs du territoire, les processus en cours, et les scénarios possibles d'évolution à l'horizon 2040. Une stratégie adaptée au deuxième scénario, retenu par les acteurs locaux, a été proposée
Food Security Survey: Phase I, Agricultural Production and Land Use Season 2000A
REPUBLIC OF RWANDA, MINISTRY OF AGRICULTURE, ANIMAL RESOURCES, AND FORESTRY, Food Security Research Project (FSRP) and Division of Agricultural Statistics (DSA)food security, food policy, Rwanda, agricultural production, land use, Food Security and Poverty, Q18,
Experimental investigation of a two-stage oil-free domestic Air/Water heat pump prototype powered by an oil-free high-speed twin-stage radial compressor rotating on gas bearings
Domestic heat pumps have been identified as a key-technology to decrease the energy consumption of the domestic sector, which represents 29% of the world final energy consumption. Space & water heating represent more than two third of the domestic sector energy consumption in many countries. Next generation domestic heat pumps powered by oil-free high-speed radial compressors are expected to (a) be more efficient at rating operating points and in partial loads, (b) to match better the energy demand characteristics, (c) to be more compact and lighter, (d) more silent, and (e) to need lower refrigerant charges. As a first step towards the development of such advanced heat pumps, an oil-free twin-stage Air/Water domestic heat pump prototype powered by an oil-free high-speed twin-stage radial compressor has been developed and tested. The heat pump layout corresponds to a two-stage heat pump cycle with an open economizer. The two main functions of the economizer are (a) to separate the liquid from the gas before the second stage compressor inlet and offer a proper mixing process, and (b) to store the liquid refrigerant not located in the heat exchangers at a given time. This key-component has been coupled with the compression unit and improved through incremental experimental steps. The heat pump driven by an oil-free twin-stage radial compressor has been successfully tested at the rating operating point A-7/W35. The performance reached with the prototype is considered very promising and constitutes a breakthrough in the domain. This article describes the experimental setup, the Operating Point (OP) A-7/W35, the methodology applied for data analysis, followed by the results. The issues limiting the performance of the prototype are also identified and briefly documented
PMMA cementoplasty in symptomatic metastatic lesions of the S1 vertebral body
We describe a lateral transiliac direct puncture approach to the SI vertebral body for polymethylmethacrylate (PMMA) cernentoplasty of painful metastatic lesions. This approach was performed using a 15-cm-long trocar needle with 3-mm outer diameter, introduced under general anesthesia and fluoroscopic control. A lateral projection was used to center the needle just in front of the spinal canal and subjacent to the superior plate of the S1 vertebral body. Needle progression was controlled using anteroposterior and lateral fluoroscopic projections alternately with a needle course parallel to an axial plane, avoiding conflict with the S1 foramen. After needle tip placement in the center of the S1 vertebral body, diluted PMMA with a setting time of 8 min was delivered. Ipsilateral lesions of the lateral sacral compartment were filled with the same needle by stepwise withdrawal and continuous PMMA injectio
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