This paper presents a full-wave method to calculate the resonant characteristics of rectangular microstrip antenna with and without dielectric cover, to explain the difference of performance with temperature between superconducting and normal conducting antenna. Especially the characteristics of high temperature superconducting (HTS) antenna were almost ideal around the critical temperature (Tc). The dyadic Green’s functions of the considered structure are efficiently determined in the vector Fourier transform domain. The effect of the superconductivity of the patch is taken into account using the concept of the complex resistive boundary condition. The computed results are found to be in good agreement with results obtained using other methods. Also, the effects of the superstrate on the resonant frequency and bandwidth of rectangular microstrip patch in a substrate–superstrate configuration are investigated. This type of configuration can be used for wider bandwidth by proper selection of superstrate thickness and its dielectric constants.

  The numerical homogenization technique is used in order to compute the effective elastic properties of heterogeneous random 2-phase composites.Differents microstructures are considered with different volume fraction.microstructure with random distribution of identical non-overlapping phases inclusions based on the Poisson process.(PBC), boundary conditions are applied on the representati ve volume element, RVE, of microstructures, for elastic modeling by finite element method. The aim of the work was to examine how spatial distribution and particles volume fraction influences the elastic  propertiesof the composite material. The results were compared to various analytical model

The paper proposes a new reliable fault-tolerant scheduling algorithm for real-time embedded systems. The proposed algorithm is based on static scheduling that allows to include the dependencies and the execution cost of tasks and data dependencies in its scheduling decisions. Our scheduling algorithm is dedicated to multi-bus heterogeneous architectures with multiple processors linked by several shared buses. This scheduling algorithm is considering only one bus fault caused by hardware faults and compensated by software redundancy solutions. The proposed algorithm is based on both active and passive backup copies to minimize the scheduling length of data on buses. In the experiments, the proposed methods are evaluated in terms of data scheduling length for a set of DSP benchmarks. The experimental results show the effectiveness of our technique.

Mobile ad hoc networks are characterized by infrastructure less, dynamic topology, without any centralized administration, and limited resources witch make more difficult the stream of multimedia applications over wireless networks. Providing Quality of Service for video streaming is an important challenge. In this paper, firstly, we have reviewed many issues and different coding techniques for video streaming over MANET and secondly we propose to study two routing protocols (AODV and DSDV) to evaluate witch of them can improve QoS for real-time multimedia applications. Results show that AODV protocol performs better than DSDV in terms of throughput and network load with high mobility, but roles are reversed in terms of bit rate, loss rate and network load for large-scale networks.

Multi-Gate Junctionless MOSFETs are promising devices to overcome the undesired short channel effects for low cost nanoelectronic applications. However, the high series resistance associated to the source and drain extensions can arise as a serious problem when dealing with uniformly doped channel, which leads to the degradation of the device performance. Therefore, in order to obtain a global view of Double-Gate Junctionless (DGJ) MOSFET performance under critical conditions, new designs and models of nanoscale DGJ MOSFET including analog performance are important for the comprehension of the fundamentals of such device characteristics. In the present paper, a numerical investigation for the drain current and small signal characteristics is conducted for the DGJ MOSFET by including highly doped extension regions. The proposed approach, which is from a practical viewpoint a feasible technique by introducing only one ion implantation step, provides a good solution to improve the drain current, small signal parameters, analog/RF behavior and linearity of DGJ MOSFET for high performance analog applications. In this context, I–V and analog characteristics of the proposed design are investigated by 2-D numerical modeling and compared with conventional DGJ MOSFET characteristics.

The influence of gate dielectric materials on the performance of a carbon nanotube field-effect transistor has been studied by a numerical simulation model. This model is based on a two-dimensional nonequilibrium Green’s function formalism performed with the self-consistent solution of the Poisson and Schrödinger equations. The device performance is investigated in terms of leakage current, on-state current, ION/IOFF current ratio, subthreshold slope, drain-induced barrier lowering, as well as transconductance, drain conductance, and intrinsic gate delay. This study is carried out over a wide range of dielectric permittivities at low temperatures ranging from room temperature down to 100 K.