University of Avignon

About: University of Avignon is a education organization based out in Avignon, Provence-Alpes-Côte-d'Azur, France. It is known for research contribution in the topics: Population & Speaker recognition. The organization has 1526 authors who have published 3766 publications receiving 88928 citations.

An Energy-Efficient Routing Scheduling based on Fuzzy Ranking Scheme for Internet of Things (IoT)

Abstract: Internet of Things (IoT) is a wireless network of various battery-powered sensing units. Due to the limited battery capacity, the non-accessible/abandoned nodes demand more energy to be reached or re-integrated to keep the network connected. When a specific tree topology for routing, called Destination Oriented Directed Acyclic Graphs (DODAG) is used, isolated nodes spend maximum energy on the assigned task during data transformation from the sensor field to the DODAG root. The nodes closer to the DODAG root need to rely on faraway nodes and resource-burden constrained nodes to lead to the quick energy drain. It brings an idea of IoT network nodes in which an extra amount of energy provide to the longer-time alive nodes. This paper proposes an ARFOR-Adaptive ranking fuzzy-based energy-efficient opportunistic routing protocol for sustainable IoT applications. The proposed protocol consists of Parent Node (PN) that acts as a head node in a cluster to aggregate the packets to DODAG root; and Volunteer Node (VN) acts as a forwarder to transfer the packets to PN with threshold energy limits to increase network lifetime during transmission cycle. The proposed VN selection is based on fuzzy parameters such as Canberra distance, residual energy, and threshold. The simulation outcomes depict that the ARFOR fairly justifies the network timeline requirement with maximum percentage area coverage. The percentage gain in terms of network lifetime is comparatively significant for a lower number of VN.

Unsupervised face identification in TV content using audio-visual sources

Abstract: Our goal is to automatically identify faces in TV content without pre-defined dictionary of identities. Most of methods are based on identity detection (from OCR and ASR) and require a propagation strategy based on visual clusterings. In TV content, people appear with many variation making the clustering very difficult. In this case, identifying speakers can be a reliable link to identify faces. In this work, we propose to combine reliable unsupervised face and speaker identification systems through talking-faces detection in order to improve face identification results. First, OCR and ASR results are combined to extract locally the identities. Then, the reliable visual associations are used to propagate those identities locally. The reliable identified faces are used as unsupervised models to identify similar faces. Finally speaker identities are propagated to the faces in case of lip activity detection. Experiments performed on the REPERE database show an improvement of the recall of +5% compared to the baseline, without degrading the precision.

Role of the Five RNA Helicases in the Adaptive Response of Bacillus cereus ATCC 14579 Cells to Temperature, pH, and Oxidative Stresses

Abstract: In this study, growth rates and lag times of the five RNA helicase-deleted mutants of Bacillus cereus ATCC 14579 were compared to those of the wild-type strain under thermal, oxidative, and pH stresses. Deletion of cshD and cshE had no impact under any of the tested conditions. Deletion of cshA, cshB, and cshC abolished growth at 12°C, confirming previous results. In addition, we found that each RNA helicase had a role in a specific temperature range: deletion of cshA reduced growth at all the tested temperatures up to 45°C, deletion of cshB had impact below 30°C and over 37°C, and deletion of cshC led mainly to a cold-sensitive phenotype. Under oxidative conditions, deletion of cshB and cshC reduced growth rate and increased lag time, while deletion of cshA increased lag time only with H2O2 and reduced growth rate at a high diamide concentration. Growth of the ΔcshA strain was affected at a basic pH independently of the temperature, while these conditions had a limited effect on ΔcshB and ΔcshC strain growth. The RNA helicases CshA, CshB, and CshC could participate in a general adaptation pathway to stressful conditions, with a stronger impact at low temperature and a wider role of CshA.

Myocardial function at the early phase of traumatic brain injury: a prospective controlled study

Abstract: The concept of brain-heart interaction has been described in several brain injuries. Traumatic brain injury (TBI) may also lead to cardiac dysfunction but evidences are mainly based upon experimental and clinical retrospective studies. We conducted a prospective case-control study in a level I trauma center. Twenty consecutive adult patients with severe TBI were matched according to age and gender with 20 control patients. The control group included adult patients undergoing a general anesthesia for a peripheral trauma surgery. Conventional and Speckle Tracking Echocardiography (STE) was performed within the first 24 post-traumatic hours in the TBI group and PRE/PER-operative in the control group. The primary endpoint was the left ventricle ejection fraction (LVEF) measured by the Simpson’s method. Secondary endpoints included the diastolic function and the STE analysis. We found similar LVEF between the TBI group and the PER-operative control group (61 % [56–76]) vs. 62 % [52–70]). LV morphological parameters and the systolic function were also similar between the two groups. Regarding the diastolic function, the isovolumic relaxation time was significantly higher in the TBI cohort (125 s [84–178] versus 107 s [83–141], p = 0.04), suggesting a subclinical diastolic dysfunction. Using STE parameters, we observed a trend toward higher strains in the TBI group but only the apical circumferential strain and the basal rotation reached statistical significance. STE-derived parameters of the diastolic function tended to be lower in TBI patients. No systematic myocardial depression was found in a cohort of severe TBI patients. STE revealed a correct adaptation of the left systolic function, while the diastolic function slightly impaired. NCT02380482