A study on the impact of AL-FEC techniques on TV over IP Quality of Experience

Abstract In this contribution, an evaluation of the effectiveness of Application Layer-Forward Error Correction (AL-FEC) scheme in video communications over unreliable channels is presented. In literature, several AL-FEC techniques for reducing the effect of noisy transmission on multimedia communication have been adopted. Recently, their use has been proposed for inclusion in TV over IP broadcasting international standards. The objective of the analysis performed in this paper is to verify the effectiveness of AL-FEC techniques in terms of perceived Quality of Service (QoS) and more in general of Quality of Experience (QoE), and to evaluate the trade-off between AL-FEC redundancy and video quality degradation for a given packet loss ratio. To this goal, several channel error models are investigated (random i.i.d. losses, burst losses, and network congestions) on test sequences encoded at 2 and 4 Mbps. The perceived quality is evaluated by means of three quality metrics: the full-reference objective quality metric NTIA-VQM combined with the ITU-T Rec. G.1070, the full-reference DMOS-KPN metric, and the pixel-wise error comparison performed by using the PSNR distortion measure. A post-processing synchronization between the original and the reconstructed stream has also been designed for improving the fidelity of the performed quality measures. The experimental results show the effectiveness and the limits of the Application Layer protection schemes

A study on the impact of AL-FEC techniques on TV over IP Quality of Experience

Abstract In this contribution, an evaluation of the effectiveness of Application Layer-Forward Error Correction (AL-FEC) scheme in video communications over unreliable channels is presented. In literature, several AL-FEC techniques for reducing the effect of noisy transmission on multimedia communication have been adopted. Recently, their use has been proposed for inclusion in TV over IP broadcasting international standards. The objective of the analysis performed in this paper is to verify the effectiveness of AL-FEC techniques in terms of perceived Quality of Service (QoS) and more in general of Quality of Experience (QoE), and to evaluate the trade-off between AL-FEC redundancy and video quality degradation for a given packet loss ratio. To this goal, several channel error models are investigated (random i.i.d. losses, burst losses, and network congestions) on test sequences encoded at 2 and 4 Mbps. The perceived quality is evaluated by means of three quality metrics: the full-reference objective quality metric NTIA-VQM combined with the ITU-T Rec. G.1070, the full-reference DMOS-KPN metric, and the pixel-wise error comparison performed by using the PSNR distortion measure. A post-processing synchronization between the original and the reconstructed stream has also been designed for improving the fidelity of the performed quality measures. The experimental results show the effectiveness and the limits of the Application Layer protection schemes

Distributed averaging on digital erasure networks

International audience; Iterative distributed algorithms are studied for computing arithmetic averages over networks of agents connected through memoryless broadcast erasure channels. These algorithms do not require the agents to have any knowledge about the global network structure or size. Almost sure convergence to state agreement is proved, and the communication and computational complexities of the algorithms are analyzed. Both the number of transmissions and the number of computations performed by each agent of the network are shown to grow not faster than poly-logarithmically in the desired precision. The impact of the graph topology on the algorithms' performance is analyzed as well. Moreover, it is shown how, in the presence of noiseless communication feedback, one can modify the algorithms, significantly improving their performance versus complexity trade-off

Maxillo-Facial Morphology in Beckwith-Wiedemann Syndrome: A Preliminary Study on (epi)Genotype-Phenotype Association in Caucasians

Beckwith–Wiedemann syndrome (BWS) is a congenital overgrowth disorder caused by various (epi)genetic alterations affecting the expression of genes on chromosome 11p15. Cardinal features include abdominal wall defects, macroglossia, and cancer predisposition. Several (epi)genotype–phenotype associations were described so far, but specific studies on the evolution over time of maxillo-facial phenotype in the molecular subtypes still are scanty. The aim of this cross-sectional study was to associate maxillo-facial morphology and growth pattern with genoype in 25 Caucasian children with BWS and macroglossia. Twelve patients experienced a loss of metilation at imprinting center 2 (IC2-LoM), five had mosaic paternal uniparental isodisomy of chromosome 11 (UPD(11)pat), and eight were negative. A more marked tongue enlargement was detected in patients with IC2-LoM and negative genotype, while UPD(11)pat children showed mild macroglossia (p = 0.048). A cluster analysis did not demonstrate any specific relationship between (epi)genotype and maxillo-facial phenotype, but separated BWS patients based on their cephalometric characteristics. Children with IC2-LoM or negative genotype displayed hyperdivergence values > 30°, clockwise growth tendency, and skeletal class II into the same cluster. They had a negative prognostic score. These preliminary data suggest the need for developing individualized protocols for early monitoring of the craniofacial growth in such patients

Joint watermarking and encryption of color images in the Fibonacci-Haar domain

A novel method for watermarking and ciphering color images, based on the joint use of a key-dependent wavelet transform with a secure cryptographic scheme, is presented. The system allows to watermark encrypted data without requiring the knowledge of the original data and also to cipher watermarked data without damaging the embedded signal. Since different areas of the proposed transform domain are used for encryption and watermarking, the extraction of the hidden information can be performed without deciphering the cover data and it is also possible to decipher watermarked data without removing the watermark. Experimental results show the effectiveness of the proposed scheme

Human parechovirus type 5 neurological infection in a neonate with a favourable outcome: A case report

The majority of parechovirus A type 5 (PeV-A5) infections have been reported in patients with gastrointestinal syndromes. In contrast, a sepsis-like illness associated with PeV-A5 infection has been reported only anecdotally. Herein, we report the first case in Italy of a PeV-A5 neurological infection presenting in a neonate with a sepsis-like syndrome. The patient, a healthy male infant born at 41 weeks of gestation, was highly distressed and inconsolable, and had been crying persistently, with poor breastfeeding, since the previous day. From day 2 to day 4, the newborn was feverish with mild irritability; breastfeeding was preserved and regularly supported. His clinical condition progressively improved, with defervescence on day 4. He was discharged after 7 days, and neurological examination results indicated only mild impairment in visual fixation and vertical eye tracking and mild axial hypotonia. The Italian PeV-A5 strain was phylogenetically related to three strains detected in Denmark in 2012, as well as to one detected in Australia and one in Greece in 2015, with an average nucleotide identity of 97.9% (range 95.9–100.0%). Enterovirus/PeV infection in the newborn should be ruled out in cases of infants with unexplained fever and/or a sepsis-like syndrome and/or meningoencephalitis. An aetiological diagnosis is essential to avoid the unnecessary administration of antibiotics and to plan long-term follow-up until schooling. Keywords: Neonatal infections, Human parechovirus type 5, CSF, Molecular characterization, CNS infection, Phylogenetic analysi

The dynamic association between Frailty, CD4 and CD4/CD8 ratio in people aging with HIV

To investigate the association between current CD4+ T-cell count and CD4/CD8+ ratio with severity of frailty among people aging with HIV

Inferring Anomaly Situation from Multiple Data Sources in Cyber Physical Systems

AbstractCyber physical systems are becoming ubiquitous devices in many fields thus creating the need for effective security measures. We propose to exploit their intrinsic dependency on the environment in which they are deployed to detect and mitigate anomalies. To do so, sensor measurements, network metrics, and contextual information are fused in a unified security architecture. In this paper, the model of the proposed framework is presented and a first proof of concept involving a telecommunication infrastructure case study is provided