Synthèse vocale et handicap

A text to speech synthesis system receives as its input textual information and produces a speech signal as an output message. In the area of multimodal interfaces, problems concerning assistive communication for handicapped people requires implementation of various technologies using the “text to speech synthesis” block. This use of vocal synthesis is aimed at users with visual deficiencies or with cerebral palsy. In this article we describe the major technical advancse producing speech from text.     

Homology modelling of rat kallikrein rK9, a member of the tissue kallikrein family: implications for substrate specificity and inhibitor binding

The rat kallikrein rK9 is one of the six members of the rattissue kallikrein family isolated to date. It is 84% identicalto rK2 (tonin), and both proteinases are thought to have vasoconstrictiveproperties. Recently we have shown that rK9 and rK2 have distinctsubstrate specificities and sensitivities to inhibitors, despitetheir similar sequences. Unlike all other mammalian kallikrein-relatedproteinases, rK9 is resistant to inhibition by aprotinin. Wehave developed a 3-D model of rK9, based on the known X-raystructures of rK2, porcine kallikrein and bovine trypsin, toidentify the structural features underlying this functionaldiversity. The final rK9 model is structurally similar to rK2,but variable regions surrounding the active site differ quitemarkedly from the reference proteins. The kallikrein loop, whichdiffers from that in porcine kallikrein by a seven-residue insertion,has been generated de novo and subjected to simulated annealingto assess its influence on the restricted substrate specificityof these proteinases. The proposed conformation of the specificitypocket in rK9 differs from that of other serine proteinases,but it can still accommodate both aromatic and basic amino acidside chains at the substrate P₁ position, thus explaining thedual chymotrypsin and trypsin-like activity of rK9. The electrostaticpotentials of rK9 and aprotinin were calculated using the finitedifference Poisson–Boltzmann method. They indicated alarge positive region near the active site of rK9 not foundin related proteinases because of positively charged residuesat positions 61 and 65 in rK9. They generate a positive region,which overlaps a positive region in aprotinin, and may preventaprotinin binding. A single mutation in aprotinin is suggestedthat might allow kallikrein rK9 inhibition by aprotinin. Thismodel contributes significantly to our understanding of thestructure-function relationships among proteinases of the tissuekallikrein family.     

Physical mapping of chromosomes VII and XV of Saccharomyces cerevisiae at 3.5 kb average resolution to allow their complete sequencing

The high resolution complete physical maps of chromosomes VII and XV were constructed to form the basis for sequencing these chromosomes as part of the European systematic sequencing programme of the yeast genome, using a unique cosmid library from strain FY1679, and an original top-down mapping strategy involving I-Sce I chromosome fragmentation. A total of 138 and 196 cosmid clones were used to construct the maps for VII and XV, respectively, forming two unique contigs that cover the entirety of chromosomes (1091 kb each), except the telomeric repeats. Colinearity of the cosmid inserts with yeast DNA was verified, and the physical maps were eventually compared with the independently generated genetic maps.     

Validation of BTRHEOM,the new rheometer for soft-to-fluid concrete

An investigation was performed on the objectivity of a new rheometer for soft-to-fluid concrete, called BTRHEOM. Firstly, the influence of concrete wall friction on the measurement of the Bingham constants was studied by finite-element simulations. It has been shown that this influence is limited, in particular on the measurement of shear yield stress. However, the quality of the estimate of plastic viscosity can be improved by applying a reduction of 10% to the bulk value. Secondly, a series of comparative tests was conducted with two other rheometers with different operating principles. The comparison with the intrinsic values as measured by a big coaxial-cylinder viscometer, the CEMAGREF-IMG rheometer, showed a satisfactory result for yield stress, but not for plastic viscosity, probably due to the segregation of the coarse aggregate in the CEMAGREF-IMG rheometer. For two concretes without segregation, the two rheometers yielded the same values. Another comparison with the LAFARGE rheometer (a modified version of Tattersall's two-point test) showed a good correlation between the measurements with the two instruments. Finally, the slump test was modelled by a simple numerical approach, from which a linear relation between slump and yield stress was derived. This relationship agrees with the experimental results.     

稳定度0.1℃的PWM温度控制器

本文给出TEC(热电冷却器)温度控制器设计,它能使激光功率二极管(或其他元件)温度稳定在0.1℃之内. 环境温度变化会对大多数电子系统的精度有影响.把关键元件(如高性能晶振、SAW滤波器、光放大器、激光二极管)的本机温度限制在窄范围内可提高电子系统的精度.     

Withholding information in semifree-ranging Tonkean macaques (Macaca tonkeana).

The ability of Tonkean macaques (Macaca tonkeana) to deceive partners about the location of hidden food was investigated in 4 males belonging to a group raised in a 2-acre park. Before releasing subjects in the search task, the experimenter prompted 1 of the subjects to observe where the bait was hidden. The authors found that when informed, higher ranking subjects did not significantly alter their search patterns whether tested alone or in pairs. The same held for subordinates belonging to pairs with weak dominance asymmetry. To the contrary, strongly dominated subordinates modified the number of pauses when searching in pairs. They used behavioral tactics such as avoiding being followed, stopping when being watched, or taking a wrong direction. Information withholding might be a common event in macaques. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative chunk strength in artificial grammar learning.

In 4 experiments, adherence to grammatical rules and associative chunk strength (including different measures, each calculated on the basis of the frequency with which bigrams and trigrams present in the test strings appeared in the learning strings) were manipulated independently in the test phase of an artificial grammar learning task. When participants learned few items of the grammar (Experiments 1A and 2A), the associated items were more often classified as grammatical than the nonassociated ones. On the other hand, when the learning phase included most of the grammatical items (Experiments 1B and 2B), the only effect observed was an effect of grammaticality. These results suggest that, depending on the specific constraints of the tasks, knowledge based on bigrams and trigrams and knowledge based on the abstraction of the grammatical structure can be used for the classification task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Robust real-time segmentation of images and videos using a smooth-spline snake-based algorithm.

This paper deals with fast image and video segmentation using active contours. Region-based active contours using level sets are powerful techniques for video segmentation, but they suffer from large computational cost. A parametric active contour method based on B-Spline interpolation has been proposed in to highly reduce the computational cost, but this method is sensitive to noise. Here, we choose to relax the rigid interpolation constraint in order to robustify our method in the presence of noise: by using smoothing splines, we trade a tunable amount of interpolation error for a smoother spline curve. We show by experiments on natural sequences that this new flexibility yields segmentation results of higher quality at no additional computational cost. Hence, real-time processing for moving objects segmentation is preserved.     

Surfing the brain.

In this paper, an overview with unification of techniques that deploy the wavelet transform in the spatial domain for the analysis of functional magnetic resonance imaging (fMRI) is presented.