Papers by Mohammad Ahmadi
Journal of Agricultural Science and Technology, 2015
Movement of sediment in the river causes many changes in the river bed. These changes are called ... more Movement of sediment in the river causes many changes in the river bed. These changes are called bedform. River bedform has significant and direct effects on bed roughness, flow resistance, and water surface profile. Thus, having adequate knowledge of the bedform is of special importance in river engineering. Several methods have been developed by researchers for estimation of bed form dimensions. In this investigation, bedform has been estimated using Artificial Neural Network (ANN) and Support Vector Machine (SVM) methods. The results obtained from these two methods were compared with empirical formulas of Van Rijn. The accuracy of the model was evaluated using (RMSE), (MSRE), (CE), (R 2 ) and (RB) statistical parameters. Higher values of statistical parameters indicated that the SVM model with RBF kernel function predicted the bedform more accurately than the other method. The values calculated for R 2 , RMSE, MSRE, CE and RB parameters were 0.79, 0.024, 0.066, 0.786, -0.081, res...
Research Journal of Applied Sciences, Engineering and Technology, 2015
Recently, more and more researches have been conducted on the multi-robot system by applying bioi... more Recently, more and more researches have been conducted on the multi-robot system by applying bioinspired algorithms. Particle Swarm Optimization (PSO) is one of the optimization algorithms that model a set of solutions as a swarm of particles that spread in the search space. This algorithm has solved many optimization problems, but has a defect when it is applied on search tasking. As the time progress, the global searching of PSO decreased and it converged on a small region and cannot search the other region, which is causing the premature convergence problem. In this study we have presented a simulated multi-robot search system to overcome the premature convergence problem. Experimental results show that the proposed algorithm has better performance rather than the basic PSO algorithm on the searching task.
Uploads
Papers by Mohammad Ahmadi