679 research outputs found
Lean Normalization and Organizational Stress Test: a New Approach for Quality Management System
International audienceIn this paper, the concept of " Lean Normalization " is proposed. This concept is a new way of tackling the implementation of the ISO Standard in a company. The " Lean Normalization " is composed of 6 steps inspired by the " Lean Management ". We explain every single step in this paper. We also open new horizons for this method with a new approach of the audit called the organizational stress test.Dans cet article, le concept de « Lean Normalization » est présenté. Ce concept propose une nouvelle façon d'aborder la mise en oeuvre des normes ISO dans une entreprise, avec 6 étapes inspirées du "Lean Management". Nous développerons chaque étape dans cet article. Nous ouvrons également de nouveaux horizons en proposant une approche différente de l'audit basée sur le stress test organisationnel
Joint Exploitation of Residual Source Information and MAC Layer CRC Redundancy for Robust Video Decoding
International audienceThis paper presents a MAP estimation method allowing the robust decoding of compressed video streams by exploiting the bitstream structure (i.e., information about the source, related to variable-length codes and source characteristics) together with the knowledge of the MAC layer CRC (here considered as additional redundancy on the MAC packet). This method is implemented via a sequential decoding algorithm in which the branch selection metric in the decoding trellis incorporates a CRC-dependent factor, and the paths which are not compatible with the source constraints are pruned. A first implementation of the proposed algorithm performs exact computations of the metrics, and is thus computationally expensive. Therefore, we also introduce a suboptimal (with tunable complexity) version of the proposed metric computation. This technique is then applied to the robust decoding of sequences encoded using the H.264/AVC standard based on CAVLC, and transmitted using aWiFi-like packet structure. Significant link budget improvement results are demonstrated for BPSK modulated signals sent over AWGN channels, even in the presence of channel coding
Robust MAC-Lite and soft header recovery for packetized multimedia transmission
International audienceThis paper presents an enhanced permeable layer mechanism useful for highly robust packetized multimedia transmission. Packet header recovery at various protocol layers using MAP estimation is the cornerstone of the proposed solution. The inherently available intra-layer and inter-layer header correlation proves to be very effective in selecting a reduced set of possible header configurations for further processing. The best candidate is then obtained through soft decoding of CRC protected data and CRC redundancy information itself. Simulation results for WiFi transmission using DBPSK modulated signals over AWGN channels show a substantial (4 to 12 dB) link budget improvement over classical hard decision procedures. We also introduce a sub-optimal and hardware realizable version of the proposed algorithm
Multivariate approach for brain decomposable connectivity networks
International audienceThis paper deals with the analysis of brain functional network using fMRI data. It recapitulates the concept of decomposable connectivity graph. Graphs are a usual tool to represent complex systems behavior, although edge strength estimation issues have not yet received a universally adopted solution. In the framework of linear Gaussian instantaneous exchanges, the well known partial correlation is usually introduced. However its estimation remains a challenge for highly connected or dense systems. Here, we propose to combine a wavelet decomposition and a graphical Gaussian model approach relying on decomposable graphs. This is shown to improve the estimations of brain function networks in the presence of long range dependence; the results are compared to those obtained with classical partial correlation estimators
Petrology, Geochemistry and Geodynamic Significance of the Mafic and Ultramafic Rocks of the Akou (Okondja Basin, Gabon)
The Akou section (Okondja in the Francevillian Basins, Gabon) has a set of mafic and ultrmafic magmatic rocks with various deposit patterns; interbedded basaltic flows, sills and small intrusive bodies within the formations FB francevillian series. The succession of these rocks pyroxenites, gabbros and basalts characterizes the oceanic crust. These rocks mainly consists of olivine, pyroxene, amphibole and biotite. This mineralogical continuation shows that these rocks result from process of split crystallization of an ultramafic magma. The geochemical analyses reveal the major elemental composition such as Na2O (0.24-3.47) and K2O (0.04-3.95). These values indicate that these series are originated from the alkaline magma, which is associated with within plate oceanic volcanicity
Graphe de connectivité cérébrale et longue dépendance
National audienceIn this communication, a decomposable graph based partial correlation matrix estimator is proposed for the analysis of time series exhibiting long memory properties. The estimator is derived from the set of wavelet coefficients computed at a given scale; the obtained coefficient are asymptotically uncorrelated, thus avoiding to introduce bias in the estimation. Decomposability of the graph leads to derive an explicit formulation of the maximum likelihood estimation of the partial correlation matrix; however, some spurious links must be introduced in order to insure graph decomposability. Surrogate data that mimik fMRI records are used to illustrate the pertinence and accuracy of the proposed approach. The simulations show that even for small size samples, the proposed methods outperforms the classical approaches. Furthermore, the added links do not affect the quality of the estimation. An appealing feature of decomposabilty resides in the possibility to account for conditional dependences through a clique based approach
Quantification of the pile-up effect for improving inverse mechanical analysis by means of nanoindentation
This paper deals with the identification of elastic-plastic material properties by means of nanoindentation. A dimensional analysis leads to the identification of a specific parameter based on the estimation of the pile-up effect. This parameter may be used in an inverse analysis. Theoretical aspects and experimental issues are discussed
An MDP model-based initial strategy prediction method for LoRaWAN
As one of the technologies in the wide-area network category, LoRaWAN provides a wireless network with a large capacity of end devices (ED) in long-range. With a pure Aloha protocol implemented into its MAC layer, LoRaWAN can reduce its power consumption. Besides, some orthogonal transmission parameters give LoRaWAN capability to avoid collision and packet loss. Thus, allocating transmission parameters to increase the network performance becomes a challenging issue for LoRaWAN. Some dynamic Spreading Factor (SF) allocation strategies are studied in this paper. A distributed Markov Decision Process (MDP) model is constructed for the uplink transmission of the class-A device in LoRaWAN. The model is also solved and implemented to the algorithms for the initial strategy prediction. Analytical results show that the MDP model increases the performance of the studied algorithms on the transmission of the packet
BMJ Open
OBJECTIVES: The aim of the study was to estimate the association between self-esteem and subsequent self-rated health during college years, taking into account a wide range of potential confounders. DESIGN: Prospective longitudinal study. SETTING: The French i-Share cohort. PARTICIPANTS: The sample consisted of 1011 college students. PRIMARY AND SECONDARY OUTCOME MEASURES: The association between self-esteem and later self-rated health was evaluated using multivariate modelling.Data regarding self-rated health, global self-esteem and demographic, educational, social, behavioural, environmental and financial characteristics were collected through an internet-based questionnaire. RESULTS: The 1011 participants had a median age of 21.9 years and 79% (795/1011) were females. Self-rated health was assessed a median of 8 months after the self-esteem measurement. Twenty per cent of the students declared average to very poor health (203/1011). Students with higher levels of self-esteem were more likely to declare good or very good self-rated health (adjusted OR=1.40, 95% CI 1.15 to 1.72, p value=0.001). Other factors associated with good or very good self-rated health were low body mass index, a comfortable financial situation during childhood and three personality traits (low persistence and harm avoidance and high cooperativeness). CONCLUSIONS: This study offers novel findings on the impact of self-esteem on self-rated health among college students. Interventions targeting self-esteem should be experimented during university years in order to improve health outcomes
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