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Talence, France

Chan Wai Po F.,CEA Grenoble | De Foucauld E.,CEA Grenoble | Morche D.,CEA Grenoble | Vincent P.,CEA Grenoble | Kerherve E.,IMS Laboratory
IEEE Transactions on Circuits and Systems I: Regular Papers | Year: 2011

We present a novel method simplifying matching network synthesis and design based on a tunable low-pass π matching network topology. This method exploits the Smith chart in a novel way. Analytic expressions for calculating the optimal matching network for automatically adapting the load to the source impedance are derived. This work is applied to a new antenna tuning unit concept able to calibrate the system in a single iteration process reducing strongly both the speed and the overall consumption of the antenna calibration module. The obtained matching network nodal and load quality factors are analyzed and the matching network efficiency is evaluated to highlight the impact of the imperfection in the design. The simulation and experimental results are presented to validate the proposed method and to evaluate the obtained matching efficiency. We perform reflection coefficients less than-dB, high efficiency matching networks with only 258 μs to calculate the proper state of the tunable matching network under a processor delivering 40 MIPS of performance. © 2011 IEEE. Source

Oyharcabal M.,INC Research | Olinga T.,INC Research | Foulc M.-P.,INC Research | Vigneras V.,IMS Laboratory
Synthetic Metals | Year: 2012

Electrically conductive composites based on epoxy resin, anhydride hardener and polyaniline (PANI) as conductive filler have been formulated and characterized. Standard PANI (Pani) and PANI/clay (PANICN) nanofillers were used to study the impact of filler morphology on the electrical properties of composites. Clay was used as a nanostructured template to increase the PANI aspect ratio (ratio of length to diameter or thickness). The use of PANICN reduces the electrical percolation threshold of composites from 4.5 vol.% to 1.3 vol.%. Moreover, the conductivity of composites containing PANICN is improved to values superior to 10 -3 S/cm. The effects of reagents and curing conditions were also evaluated. It was demonstrated that a classical alkaline curing accelerator, such as imidazole, exhibits chemical incompatibilities with the PANI conductive form, resulting in less conductive composites. Substituting the classical alkaline curing accelerator with a cationic accelerator, such as a Lewis acid, is a promising alternative to obtain conductive epoxy composites with a low content of PANI. © 2012 Elsevier B.V. All rights reserved. Source

Wannous H.,IMS Laboratory | Lucas Y.,University of Orleans | Treuillet S.,University of Orleans
IEEE Transactions on Medical Imaging | Year: 2011

With the widespread use of digital cameras, freehand wound imaging has become common practice in clinical settings. There is however still a demand for a practical tool for accurate wound healing assessment, combining dimensional measurements and tissue classification in a single user-friendly system. We achieved the first part of this objective by computing a 3-D model for wound measurements using uncalibrated vision techniques. We focus here on tissue classification from color and texture region descriptors computed after unsupervised segmentation. Due to perspective distortions, uncontrolled lighting conditions and view points, wound assessments vary significantly between patient examinations. The main contribution of this paper is to overcome this drawback with a multiview strategy for tissue classification, relying on a 3-D model onto which tissue labels are mapped and classification results merged. The experimental classification tests demonstrate that enhanced repeatability and robustness are obtained and that metric assessment is achieved through real area and volume measurements and wound outline extraction. This innovative tool is intended for use not only in therapeutic follow-up in hospitals but also for telemedicine purposes and clinical research, where repeatability and accuracy of wound assessment are critical. © 2010 IEEE. Source

Mangas A.,Institute of Neurosciences of Castilla and Leon INCYL | Covenas R.,Institute of Neurosciences of Castilla and Leon INCYL | Geffard M.,IMS Laboratory
Current Opinion in Neurology | Year: 2010

PURPOSE OF REVIEW: Multiple sclerosis (MS) is an autoimmune and inflammatory disease of the central nervous system (CNS) that causes neurological disability in young adults and that to date has no cure. Until now, expensive and only partially efficacious therapies have become available. For this reason, researchers, clinicians and pharmaceutical companies are currently investigating new drugs for the treatment of MS. Here, we review the most recent data on drug candidates for MS. RECENT FINDINGS: In the preclinical phase, such drug candidates have shown a beneficial effect on the onset of experimental autoimmune encephalomyelitis (microtubule-stabilizing drugs, MS14, Lithium, GEMSP⋯), a decrease in CNS cell infiltrates (recombinant T cell receptor ligand, lovastatin-rolipram, ribavirin, GEMSP⋯), prevention of demyelination (lovastatin-rolipram, calpain inhibitor, lithium⋯); and a reduction of axonal loss (phenytoin, lovastatin-rolipram, calpain inhibitor). In clinical trials, drug candidates against MS have shown safety (rituximab, ustekinumab, intravenous immunoglobulin, laquinimod, BHT-3009, fumarate, chaperonin 10, GEMSP⋯), an improvement of gadolinium-enhanced lesions (protiramer, fingolimod, laquinimod, BHT-3009, fumarate, daclizumab⋯), and an improvement of the relapse rate (fingolimod, fumarate⋯). SUMMARY: Future research into MS should focus on a combination of therapies and on the development of drugs directed against the remitting and progressive phases of the disease. In this sense, MS is a very complex multifactorial disease that requires treatment able to cover all the aspects of MS and not only the anti-inflammatory aspect. © 2010 Lippincott Williams & Wilkins. Source

Gheorghe A.,IMS Laboratory | Zolghadri A.,University of Bordeaux 1 | Cieslak J.,University of Bordeaux 1 | Goupil P.,Airbus | And 2 more authors.
IEEE Control Systems | Year: 2013

Many innovative solutions have been developed by the aeronautical sector toward achieving the future ?sustainable? aircraft that will be cleaner, quieter, smarter, and more affordable. Weight reduction is one of the most significant contributors to sustainability, as it improves aircraft performance (fuel consumption, noise, range) and consequently decreases its environmental footprint. Since the 1980s, the electrical flight controls system (EFCS), also known as fly-by-wire (FBW), introduced by Airbus on civilian aircraft [1], [2], has been a weight-saving technology in which the conventional heavy mechanical linkages between the pilot?s inputs and the control surface actuators were replaced by lighter electrical signal wires and digital flight control computers (FCCs). More recently, the electro-hydrostatic actuators introduced on the A380 [3] allowed the replacement of three conventional hydraulic circuits by two hydraulic circuits plus two electric layouts, which resulted in a weight savings of about 1 ton of mass for the aircraft. For future aircraft, the next important issue is the structural design optimization, which will result in lighter, and therefore greener, aircraft. However, this design improvement leads to increased interactions between EFCS failures and structural loads. Therefore, structural optimization must be properly accompanied by advanced fault detection and diagnosis (FDD) techniques for limiting the impacts of flight control system failures. Highlighting the link between aircraft sustainability and fault detection, it can be demonstrated that improving the performance of FDD allows designers to further optimize the aircraft structural design, which in turn leads to further weight reduction. © 1991-2012 IEEE. Source

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