Radio Cognitive (RC) is the new concept introduced to improve spectrum utilization in wireless communication and present important research field to resolve the spectrum scarcity problem. The powerful ability of CR to...Radio Cognitive (RC) is the new concept introduced to improve spectrum utilization in wireless communication and present important research field to resolve the spectrum scarcity problem. The powerful ability of CR to change and adapt its transmit parameters according to environmental sensed parameters, makes CR as the leading technology to manage spectrum allocation and respond to QoS provisioning. In this paper, we assume that the radio environment has been sensed and that the SU specifies QoS requirements of the wireless application. We use genetic algorithm (GA) and propose crossover method called Combined Single-Heuristic Crossover. The weighted sum multi-objective approach is used to combine performance objectives functions discussed in this paper and BER approximate formula is considered.展开更多
In this paper,we use Lyapunov approach to study the stability of an exploited fish population system.The model considered is structured in n age classes and includes a nonlinear polynomial stock-recruitment relationsh...In this paper,we use Lyapunov approach to study the stability of an exploited fish population system.The model considered is structured in n age classes and includes a nonlinear polynomial stock-recruitment relationship.Lyapunov candidate functions is investigated and sufficient conditions for global asymptotic stability of the studied polynomial system are proposed to allow computational implementation.The results obtained extend our previous study focusing on the solution to the same problem solved using other tools of control engineering.The advantage of the proposed approach is that the derived conditions proving the stability of the studied systems can be presented as in inequality in general and feasibility tests.The obtained results are tested by numerical examples.展开更多
文摘Radio Cognitive (RC) is the new concept introduced to improve spectrum utilization in wireless communication and present important research field to resolve the spectrum scarcity problem. The powerful ability of CR to change and adapt its transmit parameters according to environmental sensed parameters, makes CR as the leading technology to manage spectrum allocation and respond to QoS provisioning. In this paper, we assume that the radio environment has been sensed and that the SU specifies QoS requirements of the wireless application. We use genetic algorithm (GA) and propose crossover method called Combined Single-Heuristic Crossover. The weighted sum multi-objective approach is used to combine performance objectives functions discussed in this paper and BER approximate formula is considered.
文摘In this paper,we use Lyapunov approach to study the stability of an exploited fish population system.The model considered is structured in n age classes and includes a nonlinear polynomial stock-recruitment relationship.Lyapunov candidate functions is investigated and sufficient conditions for global asymptotic stability of the studied polynomial system are proposed to allow computational implementation.The results obtained extend our previous study focusing on the solution to the same problem solved using other tools of control engineering.The advantage of the proposed approach is that the derived conditions proving the stability of the studied systems can be presented as in inequality in general and feasibility tests.The obtained results are tested by numerical examples.
