Publications Scientifiques

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End date: 2009Subject: search.filters.subject.Reliability

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Now showing 1 - 9 of 9
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    Bi-objective optimization algorithms for joint production and maintenance scheduling : application to the parallel machine problem
    (Springer, 2009) Berrichi, A.; Amodeo, L.; Yalaoui, F.; Châtelet, E.; Mezghiche, Mohamed
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    Reliability assessment and improvement of medium power induction motor winding insulation protection system using predictive analysis
    (Springer, 2009) Chafai, M.; Refoufi, L.; Bentarzi, Hamid
    This chapter presents a reliability assessment of a widely used protection system of medium-power squirrel cage induction motors. In conjunction with published field induction motors reliability data, this assessment effort is based on a predictive analysis integrating three predictive techniques: (1) a fault tree analysis (FTA) that allows to identify and then quantify the initiating events weighting factors; (2) an event tree analysis (ETA) that allows to predict the protection system probability outcomes following an external disturbance; and (3) a failure mode effect and criticality analysis (FMECA) that will help set the stage to develop a preventive maintenance program fit to keep up the induction motor protection system reliability at the required level with particular attention given to aggressive environmental factors such as found in cement plants
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    Reliability assessment and improvement of large power induction motor winding insulation protection system using predictive analysis
    (2008) Chafai, Mahfoud; Refoufi, Larbi; Bentarzi, Hamid
    The paper presents a reliability assessment of a widely used protection system of large power squirrel cage induction motors. In conjunction with published field induction motors Failure data this assessment effort is based on a integrated predictive analysis using three methods: (1) a Fault Tree Analysis (FTA) that allows to identify and then quantify the initiating failure cause weighting factors; (2) an Event Tree Analysis (ETA) that allows to predict the protection system probability outcomes following an external disturbance and (3) a Failure Mode Effect and Criticality Analysis (FMECA) that will help set the stage for developing a preventive maintenance program fit to keep up the induction motor protection system reliability at the required level with particular attention given to aggressive environmental factors such as found in cement plants
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    Optimization of the structures of the electric feeder systems of the oil pumping plants in Algeria
    (2007) Bouguerra, M.; Laaouad, F.; Habi, I.; Azaizia, Rachid
    In Algeria, now, the oil pumping plants are fed with electric power by independent local sources. This type of feeding has many advantages (little climatic influence, independent operation). However it requires a qualified maintenance staff, a rather high frequency of maintenance and repair and additional fuel costs. Taking into account the increasing development of the national electric supply network (Sonelgaz), a real possibility of transfer of the local sources towards centralized sources appears.These latter cannot only be more economic but more reliable than the independent local sources as well. In order to carry out this transfer, it is necessary to work out an optimal strategy to rebuilding these networks taking in account the economic parameters and the indices of reliability
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    Optimization of preventive repair in a dynamic system of machines
    (2009) Benmounah, A.; Hachemi, T.
    The determination of the number of preventive repair to make in a park of machines in a given period, in the majority of practical cases, is based on the knowledge of essential parameters obtained from the statistics such as: 1) Mean life duration of the equipment 2) Mean functioning duration until the first failure 3) Mean functioning duration between the failures 4) renewing intensity of the pa k of machines. However theses values cannot be taken as credible base data to be able to optimise the number of repair of machines in a dynamic exploitation system of a park of machines and obtain the wanted number of machines at the end of the planned period. The cited 4 parameters depend on 2 principal factors: • Evolution and importance of the park of machines (variable in time) • Exploitation methods in the park (repair quality and used means). The renewing intensity of the park of machines is a function of the demand and degradation intensity of machines. From another side, the repair duration depend on the functioning periodicity cited here, on their nature and their costs. These last influence, in a significant manner, the calculus results. It is then primordial to look for the solution of the problem by introducing the notion of parameters optimum values. In this paper is given a new approach of the problem, which studies the dependence of the cited parameters, of the exploitation time and of the importance of the park of machines always renewed. This has for effect to act directly on the costs due to this dependence that is: • The renewing costs (purchase of new machines and new repair means); • The exploitation and repair costs. This method permits to obtain optimal values: • Of the number of repairs; • Of the number of machines to purchase in the planned period; • Of the exploitation duration of every machine
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    Optimisation du réseau algérien de transport de brut et de condensat = optimization of the algerian crude and condensate network
    (2000) Smati, A.; Zeraibi, Noureddine; Touabti, M. C.
    Le diagnostic et l'extension optimale du réseau algérien de transport de brut et de condensat, en liaison avec l'intensification des rythmes de production, nécessitent la mise au point de procédures systémiques de modélisation. Dans ce contexte, le pompage par batch est représenté par des bi-flots. L'arsenal de la théorie des graphes et le problème du flot maximal, associé à un modèle de fiabilité, sont ensuite mis à contribution. Le modèle global peut alors être utilisé comme stand d'expérimentation où l'impact de chaque décision ou événement est dégagé par simulation. Cependant, en raison de la non-linéarité des coûts, l'extension optimale du réseau est soumise à la résolution d'un modèle de programmation non linéaire
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    Markovian approach of safety engineering of a machines system
    (2009) Benmounah, A.
    To manage exploitation of a system of machine intended to complete a given work is to guarantee the possibility of having this system in operating condition for one determined duration before preventive repair with a given reliability. It is also to have with the availability of the repair service the quantity of parts necessary for this repair in order to the minimum reduce the time of the forced stopping of the engines. The number of machines (elements) depends especially of the repair quality, the strategy of maintenance and of the repair shop importance. The purpose of the study consists, by using the theory of renewal, the graphs of Markov, and that of the queues while passing from a state to another, to find the dependence between the number of machines to be put in redundancy and the importance of the workshop (stands of repair) and thus to have the sufficient number in order to have an availability guaranteeing the correct operation of the company
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    Improvement of the reliability of the industrial electric networks
    (2007) Bouguerra, M.; Habi, I.
    The continuity in the electric supply of the electric installations is becoming one of the main requirements of the electric supply network (generation, transmission, and distribution of the electric energy). The achievement of this requirement depends from one side on the structure of the electric network and on the other side on the avaibility of the reserve source provided to maintain the supply in case of failure of the principal one. The avaibility of supply does not only depends on the reliability parameters of the both sources (principal and reserve) but it also depends on the reliability of the circuit breaker which plays the role of interlocking the reserve source in case of failure of the principal one. In addition, the principal source being under operation, its control can be ideal and sure, however, for the reserve source being in stop, a preventive maintenances which proceed on time intervals (periodicity) and for well defined lengths of time are envisaged, so that this source will always available in case of the principal source failure. The choice of the periodicity of preventive maintenance of the source of reserve influences directly the reliability of the electric feeder system In this work and on the basis of the semi- markovian’s processes, the influence of the time of interlocking the reserve source upon the reliability of an industrial electric network is studied and is given the optimal time of interlocking the reserve source in case of failure the principal one, also the influence of the periodicity of the preventive maintenance of the source of reserve is studied and is given the optimal periodicity
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    Determination of the optimal preventive maintenance of the reserve source in the industrial electric network
    (2006) Bouguerra, M.; Meglouli, H.; Habi, I.
    The great majority of the electric installations belong to the first and second category. In order to ensure a high level of reliability of their electric system feeder, two power supply sources are envisaged, one principal , the other of reserve, generally a cold reserve (electric diesel group). The principal source being under operation, it’s control can be ideal and sure, however for the reserve source being in stop, a preventive maintenance’s which proceed on time intervals (periodicity) and for well defined lengths of time are envisaged, so that this source will always available in case of the principal source failure. The choice of the periodicity of preventive maintenance of the source of reserve influences directly the reliability of the electric feeder system. On the basis of the semimarkovians processes, the influence of the periodicity of the preventive maintenance of the source of reserve is studied and is given the optimal periodicity