Fatimah Sham Ismail

Optimization of electronics component placement design on PCB using self organizing genetic algorithm (SOGA)

The optimal placement of electronic components on a printed circuit board (PCB) requires satisfying multiple conflicting design objectives as most of the components have different power dissipation, operating temperature, types of material and dimension. In addition, most electronic companies are currently emphasizing on designing a smaller package electronic system in order to increase the system performance. This paper presents a new self organizing genetic algorithm (SOGA) method for solving this multi-objective optimization problem. The SOGA can be viewed as a cascade of two GAs which consists of two steps fitness evaluation process to ensure that the fitness of selected chromosomes for each iteration process is optimally selected. The algorithm is developed based on weighted sum approach genetic algorithm (WSGA) where an inner loop GA is used to optimize the selection of weights of the WSGA. Experiments are conducted to evaluate the performance of SOGA. Four objective functions are formulated in the experiments which are temperature of components, area of PCB, high power component placement and high potential critical components distance. Comparisons of the performance of SOGA are made with two well known methods namely fixed weight GA (FWGA) and random weighted GA (RWGA). The results show that the SOGA gives a better optimal solution as compared to the other methods.

Pump scheduling optimization model for water supply system using AWGA

The water supply system has a high operational cost associated with its operations. This is characteristically due to the operations of the pumps that consume significantly high amount of electric energy. In order to minimize the electric energy consumption and reduce the maintenance cost of the system, this paper proposes the use of an Adaptive Weighted sum Genetic Algorithm (AWGA) in creating an optimal pump schedule, which can minimize the cost of electricity and satisfy the constraint of the maximum and minimum levels of water in the reservoir as well. The Adaptive weighted sum GA is based on popular weighted sum approach GA for multi-objective optimization problem wherein the weights multipliers of the individual fitness functions are adaptively selected. The algorithm has been tested using a hypothetical case study and promising results have been obtained and presented.

Model-based fault detection and diagnosis optimization for process control rig

One of the challenges research on model based fault detection and diagnosis of a system is finding the accurate models. In this paper, fuzzy logic based model using genetic algorithm for optimizing the membership function is used in the development of fault detection and diagnosis of a process control rig. The model is used to generate various residual signals, which relate to the faults of the system. These residual signals are used by artificial neural networks to classify the respective faults and finally to determine the faults of the system. Comparisons of the fault classification technique are done for two different models of the process control rig that are the conventional fuzzy model and the optimized fuzzy-GA model. The results show that the fuzzy-GA model gives more accurate fault classifications as compared to the conventional fuzzy logic model.

Thermal optimization formulation strategies for multi-constraints electronic devices placement on PCB

This paper presents an algorithm for thermal optimization formulation strategies for multi-heat generation of integrated circuit (IC) on printed circuit board (PCB). Weighted-sum approach for multi-objective genetic algorithm (WMOGA) with formulated initial placement and multi-constraints parameters (FIPMCP) are presented. FIPMCP is used for the components selection and components to PCB placement mapping procedures for random initial population. The objectives are to optimize thermal distribution f(T) of electronic components on PCB and the PCB area f(A) needed simultaneously. For multi-objective optimization process, non-dominated optimal solutions and the best fitness WMOGA over iterations are plotted for both cases in order to obtain the best PCB optimal design solution. The results show that the best solution of f(T), f(A) and F(T, A) are minimized by 1.80%, 8.54% and 4.97% respectively.

A review on 3-D magnetic property testing system for measuring rotational core loss of soft magnetic materials

In todays world, the development of electromagnetic devices require the magnetic cores to be operated at higher frequency. Soft magnetic composite (SMC) materials are suitable for these applications because of their properties like high electrical resistivity which leads to the low eddy current loss, and 3-D magnetic isotropy which provides great design flexibility of various electromagnetic devices. On top of that, the prediction of core losses is very important in obtaining the optimum design of the electrical machines which is always aiming for high efficiency. This paper reviews the development of 3-D magnetic property testing system or 3-D tester in studying the rotational core loss of SMC materials based on the previous researches in the last decade.

Power Consumption Modeling for Indoor Environment Using Artificial Neural Network

In this paper, a new Artificial Neural Network (ANN) model that relates human comfort and electrical power consumption of a building with temperature, illumination and carbon dioxide (CO2) level inside the building is developed. The model has been developed using samples of simulated data representing the indoor environment variables. Results have shown that neural network with 14 hidden layer neurons produces outputs that is closest to the actual system outputs.

Multi-objective optimization problems: Method and application

Self organizing genetic algorithm (SOGA) is a class of heuristic multi-objective optimization method that has high capabilities for solving multiple conflicting objective functions. This paper presents an application of SOGA for optimizing multi-objectives components placement of multi voltage regulator (MVR) system on printed circuit board by considering multi-constraint parameters. The simulation results, which are developed based on experimental measurement, show that the SOGA can propose better optimal solution compared to the initial design.

Simulation and Segmentation Techniques for Crop Maturity Identification of Pineapple Fruit

Image segmentation is the most important steps in image processing process, especially in detecting and segmenting the main focus object from its background or others unwanted image. The objective of this paper is to develop a segmentation technique for pineapple fruit from crop background at the plantation level. Hue value is used to remove the ground and sky from the image. Then, Adaptive Red and Blue chromatic (ARB) is implemented to segmenting the pineapple fruit from the background such as leaves. In this case, the ARB method is still produced misclassifies error. Further segmentation uses Ellipse Hough Transform (EHT) for results enhancement, so that the fruit’s image is completely filtered from misclassify and background. The results obtained show that the proposed technique manages to identify the fruit from the background with better image output compared to conventional method.

Magnetic Force Model Approach with Path Finding Feature for an Improved Crowd Movement Simulation

Crowd model has been very important in the investigation and study of the dynamics of a crowd. Crowd analysis using simulation models such as the Social Force Model (SFM) in representing crowd dynamics is instrumental in this study where experiments with real humans are not practical. However, the SFM lacks features that can represent more detailed individual characteristics and realistic movement when dealing with multi-room environment. Therefore, in this paper, we propose some modifications to the original SFM with a magnetic model approach that also integrates a path finding feature to produce a more realistic simulation of individuals’ movements in the crowd. Results show that common collective crowd behaviours have been produced by the modified crowd model in a multi-room environment.

Thermal performance analysis for optimal passive cooling heat sink design

Recent advances in semiconductor technology show the improvement of fabrication on electronics appliances in terms of performance, power density and even the size. This great achievement however led to some major problems on thermal and heat distribution of the electronic devices. This thermal problem could reduce the efficiency and reliability of the electronic devices. In order to minimize this thermal problem, an optimal cooling techniques need to be applied during the operation. There are various cooling techniques have been used and one of them is passive pin fin heat sink approach. This paper focuses on inline pin fin heat sink, which use copper material with different shapes of pin fin and a constant 5.5W heat sources. The simulation model has been formulated using COMSOL Multiphysics software to stimulate the pin fin design, study the thermal distribution and the maximum heat profile.