Uniform stability of displacement coupled second-order equations

We prove that the uniform stability of semigroups associated to displacement coupled dissipator systems is equivalent to the uniform stability of velocity coupled dissipator systems. Using this equivalence, we give sufficient conditions for obtaining uniform stability and exact controllability of displacement coupled dissipator systems

On the stability of Timoshenko-type systems with internal frictional dampings and discrete time delays

International audienceIn this paper, we consider a vibrating system of Timoshenko-type in a bounded one-dimensional domain under Dirichlet-Dirichlet or Dirichlet-Neumann boundary conditions with one or two discrete time delays and one or two internal frictional dampings. First, we show that the system is well posed in the sens of semigroup theory. Second, we prove the exponential stability regardless to the speeds of wave propagation of the system if the weights of the time delays are smaller than the ones of the corresponding dampings, respectively. However, when the weight of one time delay is not smaller than the one of the corresponding damping, we prove the exponential stability in case of equal-speed wave propagation, and the polynomial stability in the opposite case

Stabilization Results of a Piezoelectric Beams with Partial Viscous Dampings and Under Lorenz Gauge Condition

In this paper, we investigate the stabilization of a one-dimensional piezoelectric (Stretching system) with partial viscous dampings. First, by using Lorenz gauge con- ditions, we reformulate our system to achieve the existence and uniqueness of the solution. Next, by using General criteria of Arendt–Batty, we prove the strong stabil- ity in different cases. Finally, we prove that it is sufficient to control the stretching of the center-line of the beam in x-direction to achieve the exponential stability. Numerical results are also presented to validate our theoretical result

Boundary Stabilization of Memory Type for the Porous-Thermo-Elasticity System

We consider the one-dimensional viscoelastic Porous-Thermo-Elastic system. We establish a general decay results. The usual exponential and polynomial decay rates are only special cases

Stabilization of a linear Timoshenko system with infinite history and applications to the Timoshenko-heat systems

In this article, we, first, consider a vibrating system of Timoshenko type in a one-dimensional bounded domain with an infinite history acting in the equation of the rotation angle. We establish a general decay of the solution for the case of equal-speed wave propagation as well as for the nonequal-speed case. We, also, discuss the well-posedness and smoothness of solutions using the semigroup theory. Then, we give applications to the coupled Timoshenko-heat systems (under Fourier's, Cattaneo's and Green and Naghdi's theories). To establish our results, we adopt the method introduced, in [13] with some necessary modifications imposed by the nature of our problems since they do not fall directly in the abstract frame of the problem treated in [13]. Our results allow a larger class of kernels than those considered in [28,29,30], and in some particular cases, our decay estimates improve the results of [28,29]. Our approach can be applied to many other systems with an infinite history

La diversité des formes de performance au travail : le rôle de la justice organisationnelle

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Exhaustion of Employees in SMEs: the role of Employability

International audienceIn a workplace, exhaustion/depletion, also known as burnout, may be a source of weakening and wearing of ‘vital’ energy of employees. Beyond the physical and psychological consequences for individuals, a company also suffers the costs of situations of depletion/exhaustion of employees. Drawing on Conservation of Resources theory, we argued that employability is an important personal resource that could help employees in reducing their feelings of being depleted. This study among 209 French employees working in the automotive sector examined the relationship between employability and depletion/exhaustion. Result indicated that two facets of employability (i.e. occupational expertise and balance) were negatively related to exhaustion. These findings suggest that organizations should build family friendly organizational environment, facilitate knowledge sharing, and focus on employees’ personal development to increase the well-being of employees. At the end, theoretical and practical implications are presented