Reliability of a k-out-of-n: G System Subjected to Marshall-Olkin Type Shocks Concerning Magnitude

In this paper the reliability of a k-out-of-n: G system under the effect of shocks having the Marshall-Olkin type shock models, is studied. The magnitudes of the shocks are considered. The system contains n components and only functions when at least k of these components function. The system is subjected to (n + 1) shocks coming from (n + 1) different sources. The shock coming from the it h source may destroy the it h component, i = 1, . . . , n, while the shock coming from the (n + 1)t h source may destroy all components simultaneously. A shock is fatal, destroys a component (components), whenever its magnitude exceeds an upper threshold. The system reliability is obtained by considering the arrival time and the magnitude of a shock as a bivariate random variable. It is assumed that the bivariate random variables representing the arrival times and the magnitudes of the shocks are independent with non-identical bivariate distributions. Since the computation of the reliability formula obtained is not easy to handle, an algorithm is introduced for calculating the reliability formula. The reliability of a k-out-of-n: G system subjected to independent and identical shocks is obtained as a special case, as well as the reliabilities of the series and the parallel systems. As an application, the bivariate exponential Gumbel distribution is considered. Also, numerical illustrations are performed to highlight the results obtained

Un déterminant de l'innovation technique en agriculture : les coordinations sur le travail dans la production bananière

The growth of the international market of the horticultural products is made possible by the globalization of an intensive mode of production in synthetic products which mobilizes salaried workers. In the Antilles changes in technological trajectories enables the consideration of other modes of production. This article brings to light how the technical innovation allowing a decrease in the necessity to use pesticides is dependent on an adaptation of the coordination in the mobilization of the salaried work. For this purpose we compare two systems of the use of manual labour between Martinique and Guadeloupe by widening on certain aspects in the transnational. The comparison is based on the characterization of these systems in which manual labour is used and the indicators of performance of the sectors of banana as well as on the adaptation of the technical changes. ...French Abstract : La croissance du marché international des produits horticoles se réalise par la globalisation d'un mode de production intensif en produits de synthèses qui mobilise une main d'oeuvre salariée. Dans les Antilles des changements de trajectoires technologiques permettent d'envisager d'autres modes de production. Cet article met en évidence comment l'innovation technique permettant de diminuer le recours aux pesticides est tributaire d'une adaptation des coordinations dans la mobilisation du travail salarié. Pour cela nous caractérisons les systèmes d'emploi de la main d'oeuvre salarié entre différentes origines et leurs impact sur des indicateurs de performance des filières de banane et d'adaptation des changements techniques.BANANA; WORK; INNOVATION; PESTICIDE; ANTILLES

Dimension dependent hypercontractivity for Gaussian kernels

We derive sharp, local and dimension dependent hypercontractive bounds on the Markov kernel of a large class of diffusion semigroups. Unlike the dimension free ones, they capture refined properties of Markov kernels, such as trace estimates. They imply classical bounds on the Ornstein-Uhlenbeck semigroup and a dimensional and refined (transportation) Talagrand inequality when applied to the Hamilton-Jacobi equation. Hypercontractive bounds on the Ornstein-Uhlenbeck semigroup driven by a non-diffusive L\'evy semigroup are also investigated. Curvature-dimension criteria are the main tool in the analysis.Comment: 24 page

A Prospective Cohort Study on IRS Gene Polymorphisms in Type 2 Diabetes Mellitus Patients during Severe/Acute Hyperglycemia Phase 1: Association with Insulin Resistance

Purpose: To investigate the genetic polymorphisms that may contribute to the worsening of insulin resistance in type 2 diabetes mellitus (T2DM) with severe or acute hyperglycemia.Methods: This is a prospective cohort study involving 156 T2DM patients with severe or acute hyperglycemia from all medical wards of the National University of Malaysia Medical Centre (UKMMC) that were placed on insulin therapy. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to determine the genetic association of insulin receptor substrate (IRS) gene with insulin resistance. Insulin resistance status was determined using the homeostatic model assessment for insulin resistance (HOMA-IR) index.Results: IRS1 polymorphisms were associated with increased insulin resistance (X2 = 5.09, p = 0.023) in T2DM patients with severe/acute hyperglycemia. IRS2 polymorphisms were not associated with insulin resistance (X2 = 0.69, p = 0.406) in this group of patients.Conclusion: IRS1 genetic factor alone may be a significant genetic determinant for insulin resistance in T2DM patients during severe/acute phase hyperglycemia.Keywords: Insulin receptor substrate, Genetic, Polymorphism, Diabetes, Insulin resistance, Hyperglycemia, IRS1, IRS

Weighted norm inequalities, off-diagonal estimates and elliptic operators. Part IV: Riesz transforms on manifolds and weights

This is the fourth article of our series. Here, we study weighted norm inequalities for the Riesz transform of the Laplace-Beltrami operator on Riemannian manifolds and of subelliptic sum of squares on Lie groups, under the doubling volume property and Gaussian upper bounds.Comment: 12 pages. Fourth of 4 papers. Important revision: improvement of main result by eliminating use of Poincar\'e inequalities replaced by the weaker Gaussian keat kernel bound

On the dynamical behavior of the ABC model

We consider the ABC dynamics, with equal density of the three species, on the discrete ring with $N$ sites. In this case, the process is reversible with respect to a Gibbs measure with a mean field interaction that undergoes a second order phase transition. We analyze the relaxation time of the dynamics and show that at high temperature it grows at most as $N^2$ while it grows at least as $N^3$ at low temperature