497 research outputs found

    INAUT, a Controlled Language for the French Coast Pilot Books Instructions nautiques

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    We describe INAUT, a controlled natural language dedicated to collaborative update of a knowledge base on maritime navigation and to automatic generation of coast pilot books (Instructions nautiques) of the French National Hydrographic and Oceanographic Service SHOM. INAUT is based on French language and abundantly uses georeferenced entities. After describing the structure of the overall system, giving details on the language and on its generation, and discussing the three major applications of INAUT (document production, interaction with ENCs and collaborative updates of the knowledge base), we conclude with future extensions and open problems.Comment: 10 pages, 3 figures, accepted for publication at Fourth Workshop on Controlled Natural Language (CNL 2014), 20-22 August 2014, Galway, Irelan

    Fluorescence and Diffuse Reflectance Spectroscopy and Endoscopy for Tissue Analysis

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    Biophotonics techniques are showing great potential for practical tissue diagnosis, capable of localised optical spectroscopy as well as wide field imaging. Many of those are generally based on the same concept: the spectral information they enable to acquire encloses clues on the tissue biochemistry and biostructure and these clues carry diagnostic information. Biophotonics techniques present the added advantage to incorporate easily miniaturisable hardware allowing several modalities to be set up on the same systems and authorizing their use during minimally invasive surgery (MIS) procedures. The work presented in this thesis aims to build on these advantages to design biophotonics instruments for tissue diagnosis. Fluorescence and diffuse reflectance, the two modalities of interest in this work, were implemented in their single point spectroscopic and imaging declinations. Two “platforms”, a spectroscopic probe setup and an optical imaging laparoscope, were built; they included either one of the two aforementioned modalities or the two of them together. The spectroscopic probe system was assembled to detect lesions in the digestive tract. In its first version, the setup included a dual laser illumination system to carry out an ex vivo fluorescence study of non-alcoholic fatty liver diseases (NAFLD) in the mouse model. Outcomes of the study demonstrated that healthy livers could be distinguished from NAFLD livers with high classification accuracy. Then, the same fluorescence probe inserted in a force adaptive robotic endoscope was applied on a fluorescence phantom and a liver specimen to prove the feasibility of recording spectra at multiple points with controlled scanning pattern and probe/sample pressure (known to affect the spectra shape). This approach proposed therefore a convincing method to perform intraoperative fluorescence measurements. The fluorescence setup was subsequently modified into a combined fluorescence/diffuse reflectance spectroscopic probe and demonstrated as an efficient method to separate normal and diseased tissue samples from the human gastrointestinal tract. Following the single point spectroscopy work, imaging studies were conducted with a spectrally resolved laparoscope. The system, featuring a CCD/filter wheel unit clipped on a traditional laparoscope was validated on fluorescence phantoms and employed in two experiments. The first one, building on the spectroscopy study of the gastrointestinal tract, was originally aimed at locating tumour in the oesophagus but a lack of tissue availability prevented us from doing so. The system design and validation on fluorophores phantoms were nevertheless described. In the second one, the underarm of a pig was imaged after injection of a nerve contrast agent in order to test the feasibility of in vivo nerve delineation. Fluorescence was detected from the region of interest but no clear contrast between the nerve and the surrounding muscle tissue could be detected. Finally, the fluorescence imaging laparoscope was modified into a hyperspectral reflectance imaging laparoscope to perform tissue vasculature studies. It was first characterized and tested on haemoglobin phantoms with varying concentrations and oxygen saturations and then employed in vivo to follow the haemoglobin concentration and oxygen saturation temporal evolutions of a porcine intestine subsequently to the pig’s termination. A decrease in oxygen saturation was observed. The last experiment consisted in monitoring the tissue re-oxygenation of a rabbit uterus transplant on the recipient animal, a successful tissue re-perfusion after the graft was highlighted

    Impacts of The Radiation Environment At L2 On Bolometers Onboard The Herschel Space Observatory

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    We present the effects of cosmic rays on the detectors onboard the Herschel satellite. We describe in particular the glitches observed on the two types of cryogenic far- infrared bolometer inside the two instruments PACS and SPIRE. The glitch rates are also reported since the launch together with the SREM radiation monitors aboard Herschel and Planck spacecrafts. Both have been injected around the Lagrangian point L2 on May 2009. This allows probing the radiation environment around this orbit. The impacts on the observation are finally summarized.Comment: 8 pages, 13 figures, 2 images, Author Keywords: Bolometers, Infrared detectors, cryogenics, radiation effects, submillimeter wave technology IEEE Terms: Bolometers, Detectors, Instruments, Picture archiving and communication systems, Protons, Silicon, Space vehicles; Radiation and Its Effects on Components and Systems (RADECS), 2011 12th European Conference. Conference location: Sevilla. Date of Conference: 19-23 Sept. 2011. Session H: Radiation Environment: Space, Atmospheric and Terrestrial (PH2

    Multispectral imaging of organ viability during uterine transplantation surgery in rabbits and sheep

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    Uterine transplantation surgery (UTx) has been proposed as a treatment for permanent absolute uterine factor infertility (AUFI) in the case of the congenital absence or surgical removal of the uterus. Successful surgical attachment of the organ and its associated vasculature is essential for the organ’s reperfusion and long-term viability. Spectral imaging techniques have demonstrated the potential for the measurement of hemodynamics in medical applications. These involve the measurement of reflectance spectra by acquiring images of the tissue in different wavebands. Measures of tissue constituents at each pixel can then be extracted from these spectra through modeling of the light–tissue interaction. A multispectral imaging (MSI) laparoscope was used in sheep and rabbit UTx models to study short- and long-term changes in oxygen saturation following surgery. The whole organ was imaged in the donor and recipient animals in parallel with point measurements from a pulse oximeter. Imaging results confirmed the re-establishment of adequate perfusion in the transplanted organ after surgery. Cornual oxygenation trends measured with MSI are consistent with pulse oximeter readings, showing decreased StO2 immediately after anastomosis of the blood vessels. Long-term results show recovery of StO2 to preoperative levels

    Optical security device for document protection using plasmon resonant transmission through a thin corrugated metallic film embedded in a plastic foil

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    The well known resonant or extraordinary transmission through an undulated metallic thin film embedded in a dielectric layer using the Plasmon modes excitation under normal incidence is industrially exploited for document protection applications. While the effect is very spectrally sensitive to the incidence angle in collinear incidence since it leads to a transmission peak separation in two peaks, it is very tolerant in conical incidence (incidence angle in the plan normal to the grating direction). This property is used to create color transmission effects by playing with the sample rotation in the two directions to enhance the contrast of such effect. Theoretical approach, modeling and experimental demonstration in the visible range on a flexible plastic foil are presented for a see-through window implemented in document security

    Émergence d'un leadership distribuĂ© pour la construction d'un enseignement

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    National audienceDuring the first year of the Bachelor degree in Mathematics and Computer Sciences at the University of Strasbourg, students discover computer science by attending a class named Algorithmics and Programming. The pedagogic team is composed of multiple teachers with various backgrounds. In this paper, we present the collective work the pedagogic team achieved to completely rework the curriculum, by switching to a new programming language and also changing the teaching method, using flipped classroom. We analyse the organization of this collective work, built by collaborative decisions, cooperative achievements and a distributed leadership. We discuss the efficiency of this organization, and the observed effects over several years.En premiĂšre annĂ©e de licence de mathĂ©matique et informatique, Ă  l’UniversitĂ© de Strasbourg, les Ă©tudiants dĂ©butent l’informatique en suivant un enseignement intitulĂ© « algorithmique et programmation ». L’équipe pĂ©dagogique est nombreuse, et constituĂ©e d’enseignants aux profils variĂ©s. Dans cette communication, nous prĂ©sentons le travail collectif rĂ©alisĂ© par l’équipe pĂ©dagogique pour remanier en profondeur l’enseignement, en changeant le langage de programmation et la mĂ©thode pĂ©dagogique (classe inversĂ©e). Nous analysons l’organisation de ce travail collectif, caractĂ©risĂ© par des dĂ©cisions collaboratives, des rĂ©alisations coopĂ©ratives et un leadership distribuĂ©. Nous discutons de l’efficacitĂ© de cette organisation, et des effets observĂ©s sur plusieurs annĂ©es

    Focal plane wavefront sensing on SUBARU/SCExAO

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    Focal plane wavefront sensing is an elegant solution for wavefront sensing since near-focal images of any source taken by a detector show distortions in the presence of aberrations. Non-Common Path Aberrations and the Low Wind Effect both have the ability to limit the achievable contrast of the finest coronagraphs coupled with the best extreme adaptive optics systems. To correct for these aberrations, the Subaru Coronagraphic Extreme Adaptive Optics instrument hosts many focal plane wavefront sensors using detectors as close to the science detector as possible. We present seven of them and compare their implementation and efficiency on SCExAO. This work will be critical for wavefront sensing on next generation of extremely large telescopes that might present similar limitations

    Angle Robust Reflection/Transmission Plasmonic Filters Using Ultrathin Metal Patch Array

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135614/1/adom201600397.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135614/2/adom201600397_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135614/3/adom201600397-sup-0001-S1.pd
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