70 research outputs found

    Autologous adipocyte graft in endoscopic treatment of vesico-renal reflux in children: a preliminary study

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    No bulking agent is ideal for endoscopically treating vesico-renal reflux in children. Many teams have tried to find a safe and efficient material, ideally an autologous material. We describe here a protocol for the use of autologous viable fat in the treatment of primary vesico-renal reflux in children aged from 3 to 15 years. Fat harvesting was done from the medial side of the thigh by manual aspiration. Samples were centrifuged to purify the graft from blood and lipid. Lastly fat was injected beneath the pathologic ureter by a conventional endoscopic technique. A voiding cystourethrography (VCUG) closed the procedure. Follow-up included renal ultrasonography the day after surgery, and one and three months later. A VCUG was performed systematically at three months and, in cases of acute pyelonephritis, during the survey

    SDN Controlled mmWave Massive MIMO Hybrid Precoding for 5G Heterogeneous Mobile Systems

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    In 5G mobile network, millimeter wave (mmWave) and heterogeneous networks (Hetnets) are significant techniques to sustain coverage and spectral efficiency. In this paper, we utilize the hybrid precoding to overcome hardware constraints on the analogonly beamforming in mmWave systems. Particularly, we identify the complicated antenna coordination and vast spatial domain information as the outstanding challenges in mmWave Hetnets. In our work, we employ software defined network (SDN) to accomplish radio resource management (RRM) and achieve flexible spacial coordination in mmWave Hetnets. In our proposed scheme, SDN controller is responsible for collecting the user channel state information (CSI) and applying hybrid precoding based on the calculated null-space of victim users. Simulation results show that our design can effectively reduce the interference to victim users and support high quality of service

    A Quality of Service Driven Approach for Clustering in Mobile Ad hoc Networks Based on Metrics Adaptation: Looking Beyond Clustering

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    Recently, research topics are focusing on clustering approaches for Ad hoc networks due to their effectiveness in building a virtual backbone formed by a set of suitableclusterheads (CH) to guarantee the communications acrossclusters. In this paper, we propose a clustering approach to elect suitable nodes’ representatives and to store minimum topology information by reducing the propagation of routing information which facilitates the spatial reuse of resource and increase the system capacity. The clusters must adapt dynamically to the environment changes, we also propose a distributed maintenance procedure that allows managing nodes’ adhesion, nodes’ handoff and CHs’ re-election. Based on our analytical model used to estimate the quality of service (QoS) parameters, we implement an admission control algorithm to determine the number of members inside a cluster that can be accommodated while satisfying the constraints imposed by the current applications. This might effectively drive congestion avoidance on the CH andinterclusters load-balancing to achieve better network resource utilization. The obtained results will help us to readjust the clustering algorithm metrics in order to provide better maintenance and QoS guarantees depending on the used applications. Through numerical analysis and simulations, we have studied the performance of our model and compared it with that of other existing algorithms. The results demonstrate better performance in terms of number of clusters, number of handoffs, number of transitions (state change) on CHs, QoS parameters, load balancing and scalability. We also observed how the connectivity and the stability are maximized when the number of nodes increases in presence of the mobility

    Protocoles et réseaux locaux: l'accès internet

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