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.

Maximizing Lifetime of Data-Gathering Trees With Different Aggregation Modes in WSNs

Abstract: We study the problem of maximizing the network lifetime of a data-gathering tree in a wireless sensor network (WSN). Both data routing and data aggregation are considered at the same time to improve the energy efficiency for data collection in WSNs. With different data-aggregation methods, three aggregation modes are studied: full aggregation, non-aggregation, and a hybrid partial-aggregation using compressive sensing. The full aggregation means that an intermediate sensor node will aggregate all the received data from its children and its own generated data into one data unit and then send it to its parent. If no aggregation is used, an intermediate sensor node will forward all the received data units plus its own data separately. For the hybrid partial-aggregation, once the number of incoming data units is bigger than a compression threshold, they will be compressed into a constant size for transmission. For each mode, an exact solution based on mixed-integer linear programming (MIP) is proposed to find the optimal data-gathering tree with the maximum network lifetime. Although non-linear relations exist between the lifetime of a sensor node and the number of data units received or transmitted, we succeed to express it by a set of linear equations. The correctness of the MIP models is proven formally. Simulation results demonstrate that the network lifetime can be increased tenfold by changing the compression threshold from five to one, which is, however, at the expense of bigger end-to-end delay and lower data accuracy. Thus, this compression threshold should be properly chosen for real applications.

Towards Multi-metric Cache Replacement Policies in Vehicular Named Data Networks

Abstract: Vehicular Named Data Network (VNDN) uses NDN as an underlying communication paradigm to realize intelligent transportation system applications. Content communication is the essence of NDN, which is primarily carried out through content naming, forwarding, intrinsic content security, and most importantly the in-network caching. In vehicular networks, vehicles on the road communicate with other vehicles and/or infrastructure network elements to provide passengers a reliable, efficient, and infotainment-rich commute experience. Recently, different aspects of NDN have been investigated in vehicular networks and in vehicular social networks (VSN); however, in this paper, we investigate the in-network caching, realized in NDN through the content store (CS) data structure. As the stale contents in CS do not just occupy cache space, but also decrease the overall performance of NDN-driven VANET and VSN applications, therefore the size of CS and the content lifetime in CS are primary issues in VNDN communications. To solve these issues, we propose a simple yet efficient multi-metric CS management mechanism through cache replacement (M2CRP). We consider the content popularity, relevance, freshness, and distance of a node to devise a set of algorithms for selection of the content to be replaced in CS in the case of replacement requirement. Simulation results show that our multi-metric strategy outperforms the existing cache replacement mechanisms in terms of Hit Ratio.

Anatomical and biochemical trait network underlying genetic variations in tomato fruit texture

Abstract: Firmness is an indicator of fruit freshness and a main component of tomato (Solanum lycopersicum) fruit texture. In this work, the genetic variability in fruit firmness and stiffness was analyzed in pre- and postharvest periods and underlying anatomical and biochemical traits were identified. Three tomato contrasted parental lines and six derived quantitative trait loci (QTL)-NILs harboring texture QTL on chromosome 4 (QTL4) and 9 (QTL9) were analyzed; the seasonal variability was assessed on two distant trusses. Firmness and stiffness were measured by compression and puncture tests at harvest and after 7-day storage at 20 °C. QTL4 poorly influenced the textural variables, on the contrary to QTL9 which increased firmness measured by puncture test and had similar effects in the two genetic backgrounds. According to this test, firmness increased along the season, but ranks among genotypes and QTL effects were hardly affected. Only some of the QTL effects were still significant after storage and firmness losses were not predicted by firmness at harvest. Fruit firmness and stiffness measured by puncture tests correlated with both morphological (locular number, R = −0.89), histological (cell size, R 0.82) and soluble sugar content (R < −0.74)) fruit traits. In contrast, compression test values hardly correlated with any of the measured traits. This work provided an original comprehensive approach to analyse fleshy fruit firmness and paves the way for a future predictive model.

Vinylcatechin dimers are much better copigments for anthocyanins than catechin dimer procyanidin b3.

Abstract: The binding constants (K) for the interaction of three copigments (CP), two epimeric vinylcatechin dimers (CP1 and CP2), and catechin dimer B3 (CP3) with two pigments, malvidin-3-glucoside (oenin) and malvidin-3,5-diglucoside (malvin), were determined. The K values clearly show that both vinylcatechin dimers have much higher affinity for oenin and malvin than dimer B3: KCP2 > KCP1 ≫ KCP3. Quantum mechanics and molecular dynamics calculations were also performed to interpret the binding data and specify the relative arrangement of the pigment and copigment molecules within the complexes.

Towards efficient disaster management: 5G and Device to Device communication

Abstract: Recent events of multiple earthquakes in Nepal and resulting loss of life and resources bring our attention to the ever growing significance of disaster management, especially in the context of large scale nature disasters such as earthquake and Tsunami. In this paper, we focus on how disaster management can benefit from recent advances in wireless communication technologies and protocols, especially mobile technologies and devices. The paper provides an overview of how the new generation of telecommunications and technologies such as 5G, Device to Device, 4G/LTE, and software defined radio can improve the potential of disaster management networks. Our survey is different from existing surveys in that we focus on recent advances and ongoing research directions in disaster management with the focus being on the use of ubiquitous mobile devices and applications.