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101.
102.
Dense sub-graphs of sparse graphs (communities), which appear in most real-world complex networks, play an important role in many contexts. Most existing community detection algorithms produce a hierarchical structure of communities and seek a partition into communities that optimizes a given quality function. We propose new methods to improve the results of any of these algorithms. First we show how to optimize a general class of additive quality functions (containing the modularity, the performance, and a new similarity based quality function which we propose) over a larger set of partitions than the classical methods. Moreover, we define new multi-scale quality functions which make it possible to detect different scales at which meaningful community structures appear, while classical approaches find only one partition. 相似文献
103.
Dr. Lubomir L. Vezenkov Dr. Vincent Martin Dr. Nadir Bettache Dr. Matthieu Simon Alexandre Messerschmitt Dr. Baptiste Legrand Prof. Jean-Louis Bantignies Prof. Gilles Subra Dr. Marie Maynadier Dr. Virginie Bellet Dr. Marcel Garcia Prof. Jean Martinez Dr. Muriel Amblard 《Chembiochem : a European journal of chemical biology》2017,18(21):2110-2114
Different intracellular delivery systems of bioactive compounds have been developed, including cell-penetrating peptides. Although usually nontoxic and biocompatible, these vectors share some of the general drawbacks of peptides, notably low bioavailability and susceptibility to protease degradation, that limit their use. Herein, the conversion of short peptide sequences into poly-α-amino-γ-lactam foldamers that adopt a ribbon-like structure is investigated. This template is used to distribute critical cationic and/or hydrophobic groups on both sides of the backbone, leading to potent short, cell-permeable foldamers with a low positive-charge content. The lead compound showed dramatically improved protease resistance and was able to efficiently deliver a biologically relevant cargo inside cells. This study provided a simple strategy to convert short peptide sequences into efficient protease-resistant cell-penetrating foldamers. 相似文献
104.
Aurelia Muller Bradley Robertson-Welsh Patrick Gaydecki Matthieu Gresil Constantinos Soutis 《Applied Composite Materials》2017,24(2):553-573
This investigation aimed to adapt the total focusing method (TFM) algorithm (originated from the synthetic aperture focusing technique in digital signal processing) to accommodate a circular array of piezoelectric sensors (PZT) and characterise defects using guided wave signals for the development of a structural health monitoring system. This research presents the initial results of a broader study focusing on the development of a structural health monitoring (SHM) guided wave system for advance carbon fibre reinforced plastic (CFRP) composite materials. The current material investigated was an isotropic (aluminium) square plate with 16 transducers operating successively as emitter or sensor in pitch and catch configuration enabling the collection of 240 signals per assessment. The Lamb wave signals collected were tuned on the symmetric fundamental mode with a wavelength of 17 mm, by setting the excitation frequency to 300 kHz. The initial condition for the imaging system, such as wave speed and transducer position, were determined with post processing of the baseline signals through a method involving the identification of the waves reflected from the free edge of the plate. The imaging algorithm was adapted to accommodate multiple transmitting transducers in random positions. A circular defect of 10 mm in diameter was drilled in the plate, which is similar to the delamination size introduced by a low velocity impact event in a composite plate. Images were obtained by applying the TFM to the baseline signals, Test 1 data (corresponding to the signals obtained after introduction of the defect) and to the data derived from the subtraction of the baseline to the Test 1 signals. The result shows that despite the damage diameter being 40 % smaller than the wavelength, the image (of the subtracted baseline data) demonstrated that the system can locate where the waves were reflected from the defect boundary. In other words, the contour of the damaged area was highlighted enabling its size and position to be determined. 相似文献
105.
Eléonore Gueit Evelyne Darque-Ceretti Patrick Tintillier Matthieu Horgnies 《Journal of Coatings Technology and Research》2012,9(3):337-346
In addition to its remarkable mechanical properties, high-performance concrete (HPC) also exhibits a very smooth surface with
low porosity, which makes it particularly suitable for esthetic applications. Unfortunately, the constant environmental aggressions
to which the urban buildings are exposed (organic or inorganic particles, algae, micro-organisms, staining from various sources)
are a threat to their structural and esthetic durability. This article proposes an innovative method to protect HPC surfaces
based on Ca(OH)2 growth at the fresh concrete/formwork interface. With the adequate surfactants used as demolding agents, it is possible to
grow a continuous layer of Ca(OH)2 at the concrete surface which closes the porosity, reduces the water uptake, and gives the surface super-hydrophilic properties,
facilitating self-cleaning mechanisms. 相似文献
106.
Matthieu Manceau Julien Gaume Agnès Rivaton Jean-Luc Gardette Guillaume Monier Luc Bideux 《Thin solid films》2010,518(23):7113-2281
X-ray photoelectron spectroscopy (XPS) was used to monitor the chemical changes resulting from irradiation (> 295 nm) in air of poly(3-hexylthiophene) (P3HT), polymer which is a good candidate for photovoltaic applications. The formation of carbonyl moieties and the stepwise oxidation of sulphur atoms were characterised. The oxidation and the cleavage of the hexyl side-chain was monitored. It is also shown that sulfur was first converted into sulfoxides, then into sulfones and finally into sulfinate esters. The formation of these ultimate degradation products provoked a disruption of π-conjugation in P3HT, leading to diminished visible absorbance. Based on these results, a mechanism of P3HT photooxidation is proposed. Comparison of XPS data with previously reported infrared and UV-visible spectral analysis showed that the information provided by these techniques is completely consistent. 相似文献
107.
108.
Matthieu Bamford Marcio Florian Gerard Louis Vignoles Jean-Christophe Batsale Carlos Alberto Alves Cairo L. Maillé 《Composites Science and Technology》2009,69(7-8):1131-1141
Two types of SiCf/SiC composites with different matrix quantities are prepared by CVR from pyrolyzed Carbon/resin composites. Experiments based on transient, space-resolved infrared thermography are developed; various assessment methods are implemented to measure simultaneously transverse and in-plane thermal diffusivities, globally and locally; the emphasis is set on the accuracy of the estimations. The material anisotropy is revealed and the influence of matrix volume fraction on the global thermal diffusivities is evaluated. Gradients of the properties are clearly visible in the samples, by use of the local analysis. The global heat conductivity values are discussed with respect to previous works. 相似文献
109.
Improving trochoidal tool paths generation and implementation using process constraints modelling 总被引:1,自引:0,他引:1
Matthieu Rauch Emmanuel Duc Jean-Yves Hascoet 《International Journal of Machine Tools and Manufacture》2009,49(5):375-383
With the emergence of high dynamic machine tools equipped with performing NC controllers, new types of strategies have risen to meet the demands associated to high-speed milling process. Among them, trochoidal tool paths are applied in rough machining applications. In this paper several improvements for their implementation are proposed. First, maximal radial depth of cut calculation according to tool path parameterization is made. Two interpolation models are tested and compared. The aim is to select the best tool path parameters according to the process constraints. Then, improved tool path generation for pocket milling applications is proposed. An experimental study is performed to validate the proposed approach and study the efficiency of trochoidal tool path implementation for pocket milling applications. The impact of the dynamics of the machine tool is evaluated in particular. The work presented here leads consequently to enhancement of implementation of trochoidal tool paths according to process constraints. 相似文献
110.
Michele Conti Matthieu De Beule Peter Mortier Denis Van Loo Pascal Verdonck Frank Vermassen Patrick Segers Ferdinando Auricchio Benedict Verhegghe 《Journal of Materials Engineering and Performance》2009,18(5-6):787-792
The widespread acceptance of carotid artery stenting (CAS) to treat carotid artery stenosis and its effectiveness compared with surgical counterpart, carotid endarterectomy (CEA), is still a matter of debate. Transient or permanent neurological deficits may develop in patients undergoing CAS due to distal embolization or hemodynamic changes. Design, development, and usage of embolic protection devices (EPDs), such as embolic protection filters, appear to have a significant impact on the success of CAS. Unfortunately, some drawbacks, such as filtering failure, inability to cross tortuous high-grade stenoses, malpositioning and vessel injury, still remain and require design improvement. Currently, many different designs of such devices are available on the rapidly growing dedicated market. In spite of such a growing commercial interest, there is a significant need for design tools as well as for careful engineering investigations and design analyses of such nitinol devices. The present study aims to investigate the embolic protection filter design by finite element analysis. We first developed a parametrical computer-aided design model of an embolic filter based on micro-CT scans of the Angioguard? XP (Cordis Endovascular, FL) EPD by means of the open source pyFormex software. Subsequently, we used the finite element method to simulate the deployment of the nitinol filter as it exits the delivery sheath. Comparison of the simulations with micro-CT images of the real device exiting the catheter showed excellent correspondence with our simulations. Finally, we evaluated circumferential basket-vessel wall apposition of a 4 mm size filter in a straight vessel of different sizes and shape. We conclude that the proposed methodology offers a useful tool to evaluate and to compare current or new designs of EPDs. Further simulations will investigate vessel wall apposition in a realistic tortuous anatomy. 相似文献