Specific surface area of some standard cotton fiber and its relation to physical properties

The specific surface area of 6 ICCS fibers, B-26, C-36, D-5, E-4, G-17 and I-26 was measured by means of methylene blue adsorption in liquid phase. The adsorption isotherm was hold at 25(C and during 24 hours. The concentration of methylene blue was in the range 0.004 - 0.18 g l-1 for each isotherm. The surface area of these standard cottons were found 32.32, 32.42, 34.48, 52.72, 43.96 and 29.91 m2 g-1 respectively. Physical properties of these cottons such as crystallinity (determined by X-ray diffractoin) and fineness (measured by gravimetric method, FMT 3 and AFIS) were measured in order to establish the relationships between the surface areas of six standard cottons and their physical properties. (Résumé d'auteur

Splitting heuristics for disjunctive numerical constraints

International audienceRatschan has recently proposed a general framework for first-order formulas whose atoms are numerical constraints. It extends the notion of consistency to logical terms, but little is done with respect to the splitting operation. In this paper, we explore the potential of splitting heuristics that exploit the logical structure of disjunctive numerical constraint problems in order to simplify the problem along the search. First experiments on CNF formulas show that interesting solving time gains can be achieved by choosing the right splitting points

Multi-non-binary turbo codes

International audienceThis paper presents a new family of turbo codes called multi-non-binary turbo codes (MNBTCs) that generalizes the concept of turbo codes to multi-non-binary (MNB) parallel concatenated convolutional codes (PCCC). An MNBTC incorporates, as component encoders, recursive and systematic multi-non-binary convolutional encoders. The more compact data structure for these encoders confers some advantages on MNBTCs over other types of turbo codes, such as better asymptotic behavior, better convergence, and reduced latency. This paper presents in detail the structure and operation of an MNBTC: MNB encoding, trellis termination, Max-Log-MAP decoding adapted to the MNB case. It also shows an example of MNBTC whose performance is compared with the state-of-the-art turbo code adopted in the DVB-RCS2 standard

The bit interleaved coded modulation module for DVB-NGH: enhanced features for mobile reception

International audienceThis paper describes the main features of the DVB-NGH Bit-Interleaved Coded Modulation (BICM) module. This latter is derived from a sub-set of DVB-T2 BICM components with additional features intended to first lower receiver complexity and power consumption and then to increase receiver robustness over mobile reception. Therefore, the long code block size was removed, a different range of coding rates was chosen, non-uniform constellations were adopted in order to provide shaping gain, and the principle of signal space diversity was extended to four-dimensional rotated constellations. Moreover the structure of the time interleaver offers the possibility to significantly increase the interleaving depth, a feature required for mobility over terrestrial and satellite links

High diversity multi-block space-time code for broadcasting applications

International audienceWe propose a STBC that calls for a 2 times 2x2 matrix seen as a two-block matrix. It enjoys a flexible transmission rate and a diversity order of 8 for a 2x2 MIMO system by exploiting additional time diversity. Its decoding complexity is only proportional to the power of four of the constellation size. The STBC parameters have been optimized to suit fading channels with and without erasure events. These events are typical of single frequency networks that are becoming a popular topology thanks to their low bandwidth requirements. Unlike state-of-the art quasi-orthogonal structures, the proposed multi-block STBC can be jointly optimized for shaping and coding gain

Intelligent Splitting for Disjunctive Numerical CSPs

International audienceDisjunctions in numerical CSPs appear in applications such as Design, Biology or Control. Generalized solving techniques have been proposed to handle these disjunctions in a Branch&Prune fashion. However, they focus essentially on the pruning operation. In this paper, we present experimental evidences that significant performance gains can be expected by exploiting the disjunctions in the branching operation

Fractoluminescence characterization of the energy dissipated during fast fracture of glass

Fractoluminescence experiments are performed on two kinds of silicate glasses. All the light spectra collected during dynamic fracture reveal a black body radiator behaviour, which is interpreted as a crack velocity-dependent temperature rise close to the crack tip. Crack velocities are estimated to be of the order of 1300 m.s$^{-1}$ and fracture process zones are shown to extend over a few nanometers.Comment: Accepted for publication in Europhysics Letters; 5 pages; 4 figure

On chip interconnects for multiprocessor turbo decoding architectures

International audienc