Amirkabir University of Technology

About: Amirkabir University of Technology is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Nonlinear system & Fuzzy logic. The organization has 15254 authors who have published 31165 publications receiving 487551 citations. The organization is also known as: Tehran Polytechnic & Tehran Polytechnic University.

EEG classification of ADHD and normal children using non-linear features and neural network

Abstract: Attention-Deficit Hyperactivity Disorder (ADHD) is a neuro-developmental disorder that is characterized by hyperactivity, inattention and abrupt behaviors. This study proposes an approach for distinguishing ADHD children from normal children using their EEG signals when performing a cognitive task. In this study, 30 children with ADHD and 30 age-matched healthy children without neurological disorders underwent electroencephalography (EEG) when performing a task to stimulate their attention. Fractal dimension (FD), approximate entropy and lyapunov exponent were extracted from EEG signals as non-linear features. In order to improve the classification results, double input symmetrical relevance (DISR) and minimum Redundancy Maximum Relevance (mRMR) methods were used to select the best features as inputs to multi-layer perceptron (MLP) neural network. As expected, children with ADHD had more delays and were less accurate in doing the cognitive task. Also, the extracted non-linear features revealed that non-linear indices were greater in different regions of the brain of ADHD children compared to healthy children. This could indicate a more chaotic behavior of ADHD children while performing a cognitive task. Finally, the accuracy of 92.28% and 93.65% were achieved using mRMR method and DISR method using MLP, respectively. The results of this study demonstrate the ability of the non-linear features to distinguish ADHD children from healthy children.

Application of collar to control scouring around rectangular bridge piers

Abstract: Various methods have been attempted to control scouring around bridge piers, such as using riprap, slots through the pier, a group of small piles in front of the pier, and collars. Following successful application of collars on circular piers for reduction of scouring, in this work the effectiveness of collars on rectangular piers was tested. Experiments were carried out in the threshold of sediment motion with piers aligned and skewed at 5° and 10° to the flow, and with collars of different widths and at various elevations. It was found that wider collars at lower levels are more effective and that effectiveness of collars reduces by increasing the skewness of the pier. Maximum reduction of scouring was 74, 56 and 35% for a collar with a width equal to the pier width at streambed elevation when pier was aligned, skewed at 5° and skewed at 10° to the flow respectively.