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Delivering audiovisual content with MPEG-21-enabled cross-layer QoS adaptation

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第5期7卷 784-793页

作者： ahmed toufik DJAMA Ismail CNRS-LaBRI Laboratory University of Bordeaux-1.351 Cours de la Libération Talence F-33405 France

Future multimedia communication systems have to support the user’s needs, the terminal capabilities, the content specification and the underlying networking technologies. The related protocols and applications must be designed from this integration perspective in a cross-layer centric manner. In this paper, we propose an implementation of a streaming service (e.g., Television over IP service) with a unified QoS management concept that enables an IP driven integration of different system components (terminal, user, content, and network). The MPEG-21 framework is used to provide a common support for imple- menting and managing the end-to-end QoS. The main focus of this paper is on the architecture design, protocols specification and implementation evaluation. Performance evaluations using PSNR and SSIM objective video quality metrics show the benefit of the proposed MPEG-21-enabled cross-layer adaptation.

关键词： Cross-layer adaptation, MPEG-21 multimedia framework, Real-time streaming, QoS

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H2 sensing properties of modified silicon nanowires

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Progress in Natural Science:Materials International 2015年第2期25卷 101-110页

作者： Latefa Baba ahmed Sabrina Naama Aissa Keffous Abdelkader Hassein-Bey toufik Hadjersi Département de physique Université Saad Dahlab de Blidaroute de Soumaa B.P. 270Blida 09000 Algeria Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE) 2Bd.Frantz FanonB.P. 140 Alger-7 MerveillesAlgerAlgeria

It has been found that the silicon nanowires modified with noble metals can be used to fabricate an effective H2 gas sensor in the present *** preparation and surface modification of silicon nanowires(Si NWs) were carried out by chemical methods. The morphology of the silicon nanowires unmodified and modified with nanoparticles of platinum, palladium, silver and gold was investigated using scanning electron microscopy(SEM). The chemical composition of the silicon nanowire layers was studied by secondary ion mass spectroscopy(SIMS) and energy dispersive X-ray analysis(EDX). The structures of type metal/Si NWs/p-Si/Al were fabricated. The electrical characterization(I–V) was performed in primary vacuum and H2 at different concentrations. It was found that the metal type used to modify the Si NWs strongly influenced the I–V characteristics. The response of these structures toward H2 gas was studied as a function of the metal type. Finally, the sensing characteristics and performance of the sensors were investigated.

关键词： Electroless chemical etching Noble metal H2sensor Silicon nanowires Morphology

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Unsteady Heat Transfer in Bilayer,and Three-Layer Materials

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Fluid Dynamics & Materials Processing 2023年第4期19卷 977-990页

作者： toufik Sahabi Smain Balaska Physics Department Faculty of SciencesUniversity of Saida Dr.Moulay TaharSaida20000Algeria Theoretical Physics Laboratory University of Oran-1-Ahmed Ben BellaOran31000Algeria

The heat transfer equation is used to determine the heat flow by conduction through a composite material along the real *** analytical dimensionless analysis is implemented in the framework of a separation of variables method(SVM).This approach leads to an Eigenvalues problem that is solved by the Newton’s *** types of dynamics are found:An unsteady condition(in the form of jumps or drops in temperatures depending on the considered case),and a permanent equilibrium(tending to the ambient temperature).The validity and effectiveness of the proposed approach for any number of adjacent layers is also *** is shown that,as expected,the diffusion of the temperature is linked to the ratio of the thermo-physical properties of the considered layers and their number.

关键词： Heat transfer conduction eigen values composite materials thermo-physical properties

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