2,860 research outputs found
Un guide de bonnes pratiques managériales au secteur public marocain
Dans un contexte de concurrence au Cerner les concepts de Ìmanagement publicÌ n'en devient que plus nĂ©cessaire. En particulier, il importe de vĂ©rifier que le management public a bien des attributs propres par rapport au management «classique» ou gĂ©nĂ©ral. Dans son livre portant sur le management public, Annie Bartoli le dĂ©finit comme Ă©tant « Lâensemble des processus de finalisation, dâorganisation, dâanimation et de contrĂŽle des organisations publiques, visant Ă dĂ©velopper leur performance gĂ©nĂ©rale et piloter leur Ă©volution dans le respect de leur vocation ».Une vocation basĂ©e sur la production dâun service public destinĂ© aux citoyens, et sur lâintĂ©rĂȘt gĂ©nĂ©ral de la sociĂ©tĂ©. Elle ajoute aussi que le management public sâappuie sur un principe gĂ©nĂ©ral du management qui est celui de la contingence : en dâautres termes, il suppose une adaptation des mĂ©thodes de gestion Ă la diversitĂ© des situations et des enjeux. Plusieurs niveaux peuvent traduire ce champ, Le niveau « micro » qui sâintĂ©resse aux interactions entre les acteurs et les systĂšmes, selon un regard de psychosociologie .Le niveau « mĂ©so » qui touche aux processus de fonctionnement des unitĂ©s publiques, dans une optique gestionnaire.Lâobjectif dans ce papier est de prĂ©senter un Ă©tat de lieu sur le management public et un guide de pratiques managĂ©riales qui sont innovantes dans ce sens
Optimal Load Restoration in Active Distribution Networks Complying with Starting Transients of Induction Motors
Large horsepower induction motors play a critical role as industrial drives
in production facilities. The operational safety of distribution networks
during the starting transients of these motor loads is a critical concern for
the operators. In this paper, an analytical and convex optimization model is
derived representing the starting transients of the induction motor in a
semi-static fashion. This model is used to find the optimal energization
sequence of different loads (static and motor loads) following an outage in a
distribution network. The optimization problem includes the optimal control of
the converter-based DGs and autotransformers that are used for the induction
motor starting. These models together with the semi-static model of the
induction motor are integrated into a relaxed power flow formulation resulting
in a Mixed-Integer Second Order Cone Programming (SOCP) problem. This
formulation represents the transient operational limits that are imposed by
different protection devices both in the motor side and network side. The
functionality of the proposed optimization problem is evaluated in the case of
a large-scale test study and under different simulation scenarios. The
feasibility and accuracy of the optimization results are validated using I)
off-line time-domain simulations, and II) a Power Hardware-In-the-Loop
experiment
Stuctural And Magnetic Characterization Of CoxZn1-x/Cu Multilayers Obtained by Electrodeposition
We present the experimental results of (CoxZn1-x/Cu)n multilayers (3<x<10) grown using the electrochemical dual bath method. The X-ray diffraction patterns have shown that the CoZn structural lattice parameters are close to those of the monoclinic CoZn13 compound. We have developed an analytical model in the X-ray kinematical theory adapted to the electrodeposited (CoxZn1-x/Cu) multilayers. We have shown that the model can give interesting structural information about the multilayer components, and reproduces the position of the satellite peaks around the main diffraction peak. Thus we have deduced the multilayer period and performed comparison between experimental results and the analytical model. The magnetic properties at room temperature reveal both superparamagnetic and ferromagnetic features. The inclusion of Zn into the magnetic layer and the existence of CoZnCu based alloy at the interfacial regions explain the magnetic properties. The magnetoresistance (MR) loop displays a broad , rounded maximum and the saturation is not observed even at high applied fields. The MR(H) behaviour and its small ratio can be attributed to interfacial effects.We present the experimental results of (CoxZn1-x/Cu)n multilayers (3<x<10) grown using the electrochemical dual bath method. The X-ray diffraction patterns have shown that the CoZn structural lattice parameters are close to those of the monoclinic CoZn13 compound. We have developed an analytical model in the X-ray kinematical theory adapted to the electrodeposited (CoxZn1-x/Cu) multilayers. We have shown that the model can give interesting structural information about the multilayer components, and reproduces the position of the satellite peaks around the main diffraction peak. Thus we have deduced the multilayer period and performed comparison between experimental results and the analytical model. The magnetic properties at room temperature reveal both superparamagnetic and ferromagnetic features. The inclusion of Zn into the magnetic layer and the existence of CoZnCu based alloy at the interfacial regions explain the magnetic properties. The magnetoresistance (MR) loop displays a broad , rounded maximum and the saturation is not observed even at high applied fields. The MR(H) behaviour and its small ratio can be attributed to interfacial effects
Tilt order parameters, polarity and inversion phenomena in smectic liquid crystals
The order parameters for the phenomenological description of the smectic-{\it
A} to smectic-{\it C} phase transition are formulated on the basis of molecular
symmetry and structure. It is shown that, unless the long molecular axis is an
axis of two-fold or higher rotational symmetry, the ordering of the molecules
in the smectic-{\it C} phase gives rise to more than one tilt order parameter
and to one or more polar order parameters. The latter describe the indigenous
polarity of the smectic-{\it C} phase, which is not related to molecular
chirality but underlies the appearance of spontaneous polarisation in chiral
smectics. A phenomenological theory of the phase transition is formulated by
means of a Landau expansion in two tilt order parameters (primary and
secondary) and an indigenous polarity order parameter. The coupling among these
order parameters determines the possibility of sign inversions in the
temperature dependence of the spontaneous polarisation and of the helical pitch
observed experimentally for some chiral smectic-{\it } materials. The
molecular interpretation of the inversion phenomena is examined in the light of
the new formulation.Comment: 12 pages, 5 figures, RevTe
Diagnostic et traitement de la Maladie du charbon Ă localisation palpĂ©brale: Ă propos dâun cas et revue de littĂ©rature
LŽanthrax est une zoonose causée par le Bacillus anthracis. les humains contractent généralement cette maladie dans des régions endémiques, par contact direct avec des animaux infectés ou avec leurs produits contaminés. Les localisations palpébrales sont rares dans la pratique clinique et posent des problÚmes de diagnostic différentiel. Les auteurs rapportent l'observation d'un patient admis dans un tableau de cellulite préseptale, avec escarre noirùtre étendue de la paupiÚre supérieure et oedÚme extensif de lŽhémiface, faisant suspecter une localisation palpébrale de la maladie du charbon. L'examen bactériologique a permis de confirmer le diagnostic. Le patient a bénéficié dŽune antibiothérapie à base de pénicilline G avec une bonne évolution.Key words: Maladie du charbon, oeil, oedÚme, blépharoplasti
Service Restoration in DG-Integrated Distribution Networks Using an Exact Convex OPF Model
The ever-increasing requirements for reliability and quality of supply suggest to enable the self-healing features of modern distribution networks. Within the context of Active Distribution Networks (ADNs), new, fast and efficient restoration strategies can be developed relying not only on switching devices to realize load transfer operation, but also on the contribution of Distributed Generators (DGs) while controlling their set points. In this paper, a global optimization method is proposed for the restoration problem in a DG-integrated distribution network. The objective is to restore a maximum of loads with a minimum number of switching operations. In order to check the technical constraints of the resulting configuration (ex., line current and bus voltage constraints), a recently published method for exact convex formulation of the OPF problem is incorporated making the restoration problem robust particularly in the case of high nodal injections. The proposed restoration model is formulated as a mixed-integer second-order cone programming (MISOCP) problem. Two test cases are used to quantify the DG effects on the quality of the restoration strategy and to demonstrate the feasibility of the identified solution in cases where general relaxation methods for OPF problem leads to inexact solutions
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