Abstract The on line behavior of the flight vehicle can be described via nonlinear simulation of the equations of motions. Where, from the control point of view, this needed to test the trajectory performance before real flight. In this article, the simulation is carried out in order to design the suitable model for a desired nominal angle of attack trajectory, which... The on line behavior of the flight vehicle can be described via nonlinear simulation of the equations of motions. Where, from the control point of view, this needed to test the trajectory performance before real flight. In this article, the simulation is carried out in order to design the suitable model for a desired nominal angle of attack trajectory, which satisfies some typical burnout parameters in active flight phase, and to test the robust performance of the longitudinal Autopilot when the moment of inertia dynamics are considered. Moreover, the nonlinearity due to saturation limits of actuator deflections is investigated. Simulation results are presented at the end of this paper, to show the effectiveness of nonlinear fuzzy Autopilot by comparing to the classical design approach, when the coupling uncertainty is considered. Read More Read Less

Abstract Wireless mesh networks have seen a real progress because of their implementation at a low cost. Thus, the planning of such networks presents many challenges for network operators. Our aim in this paper is to provide a new solution for relays placement problem using a multi-objective optimization approach.... Wireless mesh networks have seen a real progress because of their implementation at a low cost. Thus, the planning of such networks presents many challenges for network operators. Our aim in this paper is to provide a new solution for relays placement problem using a multi-objective optimization approach. Read More Read Less

Abstract In this paper we propose a hardware implementation of a regular (3,6) LDPC decoder. Two processing units corresponding respectively to the variable and Check Node are designed in order to be used in Low Density Parity Check (LDPC) decoding by the Min-Sum Algorithm (MSA). These Units are fully parallel and flexible to be used for different block length when a... In this paper we propose a hardware implementation of a regular (3,6) LDPC decoder. Two processing units corresponding respectively to the variable and Check Node are designed in order to be used in Low Density Parity Check (LDPC) decoding by the Min-Sum Algorithm (MSA). These Units are fully parallel and flexible to be used for different block length when a regular (3, 6) LDPC codes are required. The two proposed units have been first designed and implemented in software by using the high level methodology Simulink tool following a modular design approach. In a second step, these blocks were wired in order to construct a decoder block for the LDPC code (10,5). These units are also described and simulated using Very High Speed integrated circuits Hardware Description Language (VHDL). These three kinds of implementations show that the proposed high level approach is efficient for testing and validating digital circuits before being implemented on desired Field Programmable Gate Array (FPGA) device. Read More Read Less

Abstract With the emergence of wireless networking paradigm, several optimization problems are showing their usefulness to the efficient design of such networks. These problem are related, among others, to optimizing network connectivity, coverage and stability. The resolution of these problems turns out to be crucial for optimized network performance. In the case of Wireless Sensor Networks (WSN), such problems include computing... With the emergence of wireless networking paradigm, several optimization problems are showing their usefulness to the efficient design of such networks. These problem are related, among others, to optimizing network connectivity, coverage and stability. The resolution of these problems turns out to be crucial for optimized network performance. In the case of Wireless Sensor Networks (WSN), such problems include computing placement of sensors, so that network performance is optimized. However, most optimization problems formulated for WSNs are variations of NP-hard optimization problems and are thus unlikely to be solvable in polynomial time. For instance, deployment of wireless sensor networks, to achieve a desired degree of coverage, are known for their hardness to solve to optimality. Therefore heuristics methods are used to near-optimally solve such problems. In this work we present the multiple coverage optimization problems in WSNs and a new algorithm methods based on the paradigm of constraint optimization problem (COP) for solving them optimally. We formulate the optimization problems using multi-objective optimization models. Thus, for the sensors placement, the multiobjective optimization problem is obtained consisting in the maximization of the number of sensors that monitor each point of the target area. We also present experimental results in order to evaluate the effectiveness of our approach for solving optimization problems in WSNs. Read More Read Less