Stephane Villette

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In the near future, many conventional video applications are likely to be replaced by immersive video to provide a sense of ldquobeing there.rdquo This transition is facilitated by the recent advancement of 3D capture, coding, transmission, and display technologies. Stereoscopic video is the simplest form of 3D video available in the literature. ldquoColor(More)
Selenium (Se)-containing proteins have important roles in protecting cells from oxidative damage. This work investigated the effects of Se-depletion on the expression of the genes encoding selenoproteins in colonic mucosa from rats fed diets of different Se content and in human intestinal Caco-2 cells grown in Se-adequate or Se-depleted culture medium.(More)
GSM is the most wide spread mobile communications system in the world. However the security of the GSM voice traffic is not guaranteed especially over the core network. It is highly desirable to have end-to-end secure communications over the GSM voice channel. In order to achieve end-to-end security, speech must be encrypted before it enters the GSM(More)
Selenium (Se) is an essential micronutrient for human health. The biological roles of the essential micronutrient Se are attributed to its presence in a range of 20-30 selenoproteins including the cytosolic and phospholipid hydroperoxide glutathione peroxidases (GPX1 and GPX4). It has been suggested that GPX4 may play a role in regulation of leukotriene(More)
The intracellular distribution of micronutrients, as well as their uptake, is important for cell function. In some cases the distribution of micronutrients or their related proteins is determined by gene expression mechanisms. The 3' untranslated region (3'UTR) of metallothionein-1 mRNA determines localisation of the mRNA, and in turn intracellular(More)
Speech coding at very low bit rates has many applications such as answering machines, IP telephony, mobile communications, military communications etc. In this paper we describe a speech coder capable of operating at both 2.4 and 1.2kb/s, and produces good quality synthesised speech. The basic principle of the coder is based on frequency domain vocoding(More)
CELP coders, such as G.729, are often used in VoIP systems as they offer good speech quality in the absence of packet losses. However, their reliance on long-term prediction causes propagation of errors across speech frames, and therefore makes CELP coders more sensitive to packet losses. Sinusoidal coders on the other hand do not rely on long-term(More)
The European Telecommunications Standards Institute (ETSI) has launched a competition for a new mobile communications standard designed to provide better performance than the current GSM standard. This standard is to be called AMR for Adaptive Multi-Rate: the source and channel coding rates can be adapted depending on the state of the channel, thus(More)
An efficient method for quantising the magnitude of the LPresidual spectrum is proposed for high quality sinusoidal speech coding. It exploits the intra-frame perceptual preference of the magnitudes using mel-scale-based warping, and the inter-frame statistical correlation of the successive magnitude vectors using predictive coding. A switched quantiser(More)