An improved grey wolf optimizer with hyperbolic tangent updating mechanism for solving optimization problems

The original algorithm of Grey Wolf Optimizer (GWO) has a common problem which is too soon to trap in local optima. This paper presents the Improved Grey Wolf Optimizer (IGWO) by modifying the updating mechanism of the original GWO. The main idea of the new improvement is by introducing a nonlinear updating mechanism based on the hyperbolic tangent function to improve the efficiency of the exploration and the exploitation phase and to decrease the probability of trapping in local optima. The effectiveness of the new approach is evaluated on 30 well-known benchmark functions, and the results are compared with the original GWO. The preliminary findings show that the IGWO algorithm is able to obtain very competitive results in terms of objective functions minimization compared to original GWO algorithms

EEG alpha oscillation: Handwriting behavior toward working memory performance of normal children using correlation analysis

This study is mainly focused on the Electroencephalography (EEG) of alpha oscillation of normal children's handwriting behaviour and its correlation towards working memory performance. The assessment was presented to five left-handed and five right-handed children who have no records of working memory disability. The EEG signals are recorded using Neurofax-EEG 9200 (taken at channel F7, C3, F4, F8, and C4) during two assessments: Task 1 and Task 2. Raw EEG data is analysed using Discrete Wavelet Transform (DWT) which decomposes signals into different frequency bands. Correlation analysis and T-test are used to statistically identify significant interaction which occurs. The voltage activity mean value for Task 1 is 9.664 μV while Task 2 is 5.666 μV. Results showed that there is no significant difference between the working memory average means of left and right handed children. Besides that, there is no significant sensory motor performance difference between the average means of left and right handed children when carrying out the assessments. In conclusion, this study proposed that handwriting behaviour (right-handed and left-handed) does not affect the memory performance of normal children

Identification of retina image size in relation to electrooculography signal

The aim of this study is to identify retina image size relation to Electrooculography signal. USB Digital Microscope is the process to find the diameter pupil. Other than that, EEG machine Neurofax 9200 was used to acquire the EOG signal acquisition when eye move up, down, right and left. MATLAB is used to analyze the image and measure the diameter of pupil image and implement the signal acquisition that presented in the EEG machine. The image was lay emphasis on their edges, therefore easier to realize with our naked eyes. The nature of the sharpening is prejudiced by the blurring radius using difference pixel. Several approaches have been substantiated to measure the diameter of pupil such as edge detection, active contour, binarization and others. Aiming at the signal acquisition the methods that being used is Second Order Butterworth filter and frequency domain. The visual effects to form image appear sharper, the original image which is in RGB or true color that comprise a lot of noise was produced by program design using MATLAB. Base on both results, the relation between size of pupil and EOG signal can be obtained and identified

The direct strain feedback with PID control approach for a flexible manipulator: experimental results

Flexible manipulator (FM) is a robotic arm that can accomplish different tasks and the arm is a lightweight type, which means at least one dimension of their cross section is relatively small compared to their length. This project presents the development of direct strain feedback (DSFB) with PID controller for vibration control of a FM system. Strain gauge is the main sensor used as a strain measurement for giving a feedback to the system. The strain measurement also has been used as a displacement sensor at the endpoint of the link. The displacement was used to observe the performance of the system. The performances of the controllers are assessed in terms of the input tracking capability (desired position) and vibration reduction as compared to original system. Finally, the DSFB with PID has been implemented to achieve the desired performance

Universal Impulse Noise Suppression Using Extended Efficient Nonparametric Switching Median Filter

This paper presents a filtering algorithm called extended efficient nonparametric switching median (EENPSM) filter. The proposed filter is composed of a nonparametric easy to implement impulse noise detector and a recursive pixel restoration technique. Initially, the impulse detector classifies any possible impulsive noise pixels. Subsequently, the filtering phase replaces the detected noise pixels. In addition, the filtering phase employs fuzzy reasoning to deal with uncertainties present in local information. Contrary to the existing conventional filters that only focus on a particular impulse noise model, the EENPSM filter is capable of filtering all kinds of impulse noise (i.e. the random-valued and/or fixed-valued impulse noise models). Extensive qualitative and quantitative evaluations have shown that the EENPSM method performs better than some of the existing methods by giving better filtering performance

Convergence and diversity evaluation for vector evaluated particle swarm optimization

Multi-objective optimization can be commonly found in many real world problems. In computational intelligence, Particle Swarm Optimization (PSO) algorithm has increasing popularity in solving optimization problems. An extended PSO algorithm called Vector Evaluated Particle Swarm Optimization (VEPSO) has been introduced to solve multi-objective optimization problems. However, VEPSO quantitative performance measure has not been investigated. Hence, in this study, the performance of VEPSO algorithm is investigated by measuring the convergence and diversity by using standard test functions. In addition, comparisons with other optimization algorithms are also conducted. The results show that the VEPSO algorithm performs weakly in solving problems with concave, mixed, and disconnected Pareto frontier and performs badly in solving multi-modal problems

A study of the contribution of nearest-neighbour thermodynamic parameters to the DNA sequences generated by ant colony optimisation

The process of designing a set of good DNA sequences is an essential problem and one of the most practical and important research topics in DNA-based computing and the DNA nanotechnology area. In this field of research, a DNA sequence design problem is defined as a multi-objective problem, and it is evaluated using four objective functions, h-measure, similarity, continuity and hairpin. In addition, two constraints, GC content and melting temperature (Tm), are used to maintain uniform chemical characteristics of the sequences. In the authors' previous research, an ant colony system (ACS) was proposed to solve the DNA sequence design problem based on nearest neighbour. The Watson-Crick base pair ΔGo37 was used as the distance between nodes for the thermodynamic parameters in the problem models for the heuristic approach in the ACS algorithms. In the current study, a non-heuristic approach and four new models using the heuristic approach are proposed, and results from the models are compared

The direct strain feedback with PID control approach for a flexible manipulator: experimental results

Flexible manipulator (FM) is a robotic arm that can accomplish different tasks and the arm is a lightweight type, which means at least one dimension of their cross section is relatively small compared to their length. This project presents the development of direct strain feedback (DSFB) with PID controller for vibration control of a FM system. Strain gauge is the main sensor used as a strain measurement for giving a feedback to the system. The strain measurement also has been used as a displacement sensor at the endpoint of the link. The displacement was used to observe the performance of the system. The performances of the controllers are assessed in terms of the input tracking capability (desired position) and vibration reduction as compared to original system. Finally, the DSFB with PID has been implemented to achieve the desired performance