No abstract

An adaptive multiagent reinforcement learning method for solving congestion control problems on dynamic high-speed networks is presented. Traditional reactive congestion control selects a source rate in terms of the queue length restricted to a predefined threshold. However, the determination of congestion threshold and sending rate is difficult and inaccurate due to the propagation delay and the dynamic nature of the networks. A simple and robust cooperative multiagent congestion controller (CMCC), which consists of two subsystems: a long-term policy evaluator, expectation-return predictor and a short-term rate selector composed of action-value evaluator and stochastic action selector elements has been proposed to solve the problem. After receiving cooperative reinforcement signals generated by a cooperative fuzzy reward evaluator using game theory, CMCC takes the best action to regulate source flow with the features of high throughput and low packet loss rate. By means of learning procedures, CMCC can learn to take correct actions adaptively under time-varying environments. Simulation results showed that the proposed approach can promote the system utilization and decrease packet losses simultaneously.

Abstract-This paper demonstrates the one-dimensional computational results of the propagation of Gaussian electromagnetic pulse through dielectric slabs of finite thickness with variation in permittivity. The numerical approach used is the characteristic-based method solving the time-domain Maxwell curl equations involved with nonuniform permittivity. In the numerical model, all dielectric slabs are assumed to be isotropic, lossless, and linear. The permittivity of dielectric slab may increase or decrease linearly or sinusoidally. The numerical permittivity is finely discretized such that the variation between two adjacent grids is so small that the non-uniform permittivity is assumed to be piecewise continuous and consequently can be modeled as an individual block. The numerical results of various electric fields, both in the time-and frequency-domain, are presented and compared based on the dielectric slab of constant permittivity for close investigating the effects of the non-uniform permittivity distribution on the electromagnetic fields. It is also shown that under certain arrangement of Gaussian electromagnetic pulse and dielectric slab thickness the pattern of field propagation, reflection and transmission, can be reproduced in different time scales and frequency ranges.

No abstract

No abstract