Extending Coverage of High Definition TV Services over ADSL2 with Optimized Reception Quality using H.264/AVC Transrating

In this paper, we present a new Joint Source-Channel Coding (JSCC) architecture to extend the coverage of H.264/AVC High Definition (HD) video delivery over Digital Subscriber Line (DSL). The proposed solution combines low complexity H.264/AVC transrating as well as multi-carrier transmission and takes into account realistic ADSL2 specifications including all OSI layers. Both transrating and bit and power loading transmission parameters are automatically optimized in terms of end-user perceived quality, with respect to the characteristics of the given subscriber’s loop. Several originalities have been included: a new optimization algorithm has been developed, as well as a full rate-distortion modelling of the H.264/AVC transrater’s performances. Simulation results show that the proposed solution can extend the coverage area of HD video delivery up to more than one kilometre. It should allow the widespread distribution of HD video contents and increase the number of eligible subscribers.ADSL2, H.264/AVC, joint source channel coding, transrating, Quality of Experience (QoE

Comparative efficacy of two microdoses of a potentized homoeopathic drug, Cadmium Sulphoricum, in reducing genotoxic effects produced by cadmium chloride in mice: a time course study

BACKGROUND: Cadmium poisoning in the environment has assumed an alarming problem in recent years. Effective antimutagenic agents which can reverse or combat cadmium induced genotoxicity in mice have not yet been reported. Therefore, in the present study, following the homeopathic principle of "like cures like", we tested the efficacy of two potencies of a homeopathic drug, Cadmium Sulphoricum (Cad Sulph), in reducing the genotoxic effects of Cadmium chloride in mice. Another objective was to determine the relative efficacy of three administrative modes, i.e. pre-, post- and combined pre and post-feeding of the homeopathic drugs. For this, healthy mice, Mus musculus, were intraperitoneally injected with 0.008% solution of CdCl(2) @ 1 ml/100 gm of body wt (i.e. 0.8 mcg/gm of bw), and assessed for the genotoxic effects through such studies as chromosome aberrations (CA), micronucleated erythrocytes (MNE), mitotic index (MI) and sperm head anomaly (SHA), keeping suitable succussed alcohol fed (positive) and CdCl(2) untreated normal (negative) controls. The CdCl(2) treated mice were divided into 3 subgroups, which were orally administered with the drug prior to, after and both prior to and after injection of CdCl(2) at specific fixation intervals and their genotoxic effects were analyzed. RESULTS: While the CA, MNE and SHA were reduced in the drug fed series as compared to their respective controls, the MI showed an apparent increase. The combined pre- and post-feeding of Cad Sulph showed maximum reduction of the genotoxic effects. CONCLUSIONS: Both Cad Sulph-30 and 200 were able to combat cadmium induced genotoxic effects in mice and that combined pre- and post-feeding mode of administration was found to be most effective in reducing the genotoxic effect of CdCl(2) followed by the post-feeding mode

Mise en oeuvre d'architectures de transcodage vidéo H.264/AVC et SVC: application à la transmission optimisée de la vidéo haute définition

Thèse de doctorat en Electronique, Université de Valenciennes et du Hainaut-Cambrésis, 18 juilletThe works presented in this thesis are mainly part of the French ANR TOSCANE project which aims to optimize high definition video transmission. We propose two types of low complexity transrating architectures for H.264/AVC streams to adapt video bitrate to channel bandwidth. The first transrating architecture is based on frequency selectivity of residual coefficients from H.264/AVC streams. A comparison between this solution and the well known requantization processing in terms of bitrate reduction and video quality shows that our solution often gives better results. Then, our solution is included in a high definition video transmission scheme using power line communications. This type of channel can exhibit sudden changes states; as a consequence transmission needs a new channel estimation, bit and power allocation to guarantee quasi error free transmission. By means of a slight video distortion, transrating architecture is used to dynamically adapt video bitrate to channel one. The second transrating architecture is applied to H.264 SVC streams using spatial scalability. It consists in selectively removing residual coefficients of upper enhancement layer to obtain intermediate bitrates with upper spatial definition. This transrating solution is used in an ADSL transmission, allowing the extension of the area of eligibility for high definition video services while providing a progressive reduced video quality to subscribers.Les travaux présentés dans ce manuscrit de thèse se sont déroulés majoritairement dans le cadre du projet TOSCANE dont l’objectif était d’optimiser les transmissions de flux vidéo haute définition (HD). Pour cela, deux types d’architectures de transcodage à complexité réduite des flux H.264/AVC sont proposés afin d’adapter le débit vidéo à la bande passante du canal de transmission. La première architecture s’applique aux flux H.264/AVC et réalise une sélection fréquentielle des coefficients résiduels. Après comparaison en termes de réduction de débit et de qualité vidéo entre cette solution et celle par requantification, nous avons constaté que notre architecture donnait majoritairement de meilleurs résultats. Puis, cette solution est intégrée dans un scénario de transmission vidéo HD par courant porteur en ligne. Ce type de canal est soumis à des changements d’états fréquents nécessitant une nouvelle estimation du canal et allocation des bits et des puissances afin de garantir un débit quasiment sans erreur. Au prix d’une légère baisse de PSNR, les flux sont dynamiquement transcodés afin d’adapter leur débit à celui du canal et rendre la transmission possible. La seconde architecture s’applique aux flux H.264 SVC utilisant une échelonnabilité spatiale. Elle consiste à sélectionner par position fréquentielle les coefficients résiduels de la couche d’amélioration la plus haute afin d’obtenir des débits intermédiaires tout en restant dans la définition spatiale la plus élevée. Cette solution est mise en œuvre dans le cas d’une transmission ADSL, permettant d’augmenter la zone d’éligibilité des services vidéo HD et fournissant aux abonnés une qualité progressivement réduite