Salihatun Salleh

Modeling of Heat Exchanger by Using Bio-Inspired Algorithm

Modelling of heat exchanger helps to define the error that occurs during the operation. Hence by optimizing it using genetic algorithm and particle swarm optimization, the error that occurred could be minimized and compared between both algorithms. The primary objective of this study was to obtain structural model using ARMAX equation. In this study, data from heat exchanger experiment was used to determine the parameter of ARMAX equation. Using genetic algorithm and particle swarm optimization, ARMAX parameters are optimized. Hence, the transfer function represents the plant for modelling. Validation test used were autocorrelation and cross-correlation to validate between normalised data input and error. Based on the result obtained, for GA, the input parameters are-0.000214, -0.000728, -0.0020, and-0.000804 while the output parameters are-1.0000, -0.1783, -0.1473 and 0.3248. For PSO, the input parameters are 0.0104, -0.0122, -0.0067 and 0.0118 while the output parameters are-0.4274, -0.1256, -0.1865 and-0.2614. From validation test, GA produced smoother and effective result compared to PSO with less noise exists.

Parametric Modelling of a Flexible Plate Structure Using Artificial Immune System Algorithm

Parametric modelling of dynamic systems may benefit from advantages of biologically-inspired immune system, which maintains its own system against dynamically changing environments through the interaction between lymphocytes and/or antibodies. In this paper, artificial immune system with clonal selection algorithm and artificial immune network are used to identify the unknown parameters characterising a flexible plate system. The identification is performed on basis of minimising the mean-squared output error and is assessed with correlation tests and in time and frequency domains. The approach is tested with three different disturbance signals. Simulation results demonstrate the potential of artificial immune system as promising technique with fast convergence and less computational time in comparison to binary-coded genetic algorithm.

PSO-Based Parametric Modelling of a Thin Plate Structure

Parametric modelling of dynamic structure may benefits from features of particle swarm optimization (PSO), which robust and fast in solving nonlinear, non-differentiable, and multimodal problems. This paper presents the PSO approach which includes an improved algorithm to model a flexible plate structure parametrically. The introduction of a dynamic spread and momentum factor, both by modifying the inertial weight of each particle, solves the problem of getting stuck at local optima, preserves diversity and trades-off between exploration and exploitation. The identification is performed on basis of minimizing the mean-squared output error and is assessed with correlation tests and in time and frequency domains. It is shown input-output characterization in time and frequency domains that the improved algorithm possesses features of accuracy and quick convergence.

Modelling and Control of Fish Feeder System

Food and feeding become a major challenge in aquaculture development. The way adjustment of food delivery to pond is an important role to get the maximum return or profit to aquaculture entrepreneurs. This project presents an investigation about the fish feeding system, a system device to feed fish at predetermined amounts of food and time. Moreover, the system is designed with a computer monitored system in order to manage and control the system with simulation. This project is a simulation investigation into the development of PID controller using Matlab/Simulink software. The simulation development of the PID controller with the mathematical model of fish feeder system is done using trial and error method. The PID parameter is to be tested with a DC motor. As a result, the best value of PID controller is achieved when Kp = 100, Ki = 0.05 and Kd = 25.

Artificial immune network model based controller for vibration suppression of flexible structures

This paper presents a model based controller with immune inspired algorithm to suppress flexible plate vibration. Artificial immune network (AiNet) algorithm with real-valued random initialisation of antibodies is considered to optimise the system model for use in active vibration controller development in a single-input and multi-output (SIMO) configuration. The AiNet model based controller thus developed shows the capability of the approach with relatively better accuracy in comparison to using real-coded genetic algorithm. The simulation results also reveal improvement in vibration reduction and less computational time.

Active Vibration Control of a Flexible Plate Structure Using Ant System Algorithm

This paper presents investigations into modeling and active vibration control (AVC) of a flexible plate structure using continuous ant system algorithm (CASA) such structures. The optimization technique is utilized to obtain a dynamic model of a flexible plate structure based on auto-regressive with exogenous (ARX) input model structure. The flexible plate structure is subjected to two different disturbance signal types, namely random, and finite duration step. The fitness function for the CASA is the mean-squared error (MSE) between the measured and estimated outputs of the plate. The validation of the algorithm is presented in both time and frequency domains. The developed CASA modeling approach is used for AVC system design to suppress the vibration of the flexible plate. The performance of the controller is assessed in terms of level of attenuation achieved in the power spectral density of the observed signal.

Preliminary assessment of Salvadora persica whitening effects on extracted stained teeth

The roots, twigs and stems of Salvadora persica (S. persica) also known as miswak have been used for centuries as oral hygiene tools. The cleansing efficacy of S. persica is thought to be attributed to the mechanical effects of its fibres. However, there is no study focus on S. persica whitening behaviour. Therefore, this study is conducted to preliminarily assess the whitening effects of S. persica on coffee and tea stained teeth. The bark of S. persica stems were peeled off and the pulps were dried and ground to produce powder. Scanning Electron Microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX) were carried out to study the properties of S. persica fibre. SEM revealed the presence of crystals of various shapes and sizes that act as natural abrasive agents and might contribute to its whitening effects while EDX identified that these minerals constitute of O (43.44 wt%), C (31.2 wt%), S (11.7 wt%), Ca (11.2 wt%), Na (1.3 wt%) and K (1.04 wt%). The powder later formulated into paste of various concentrations; 0.3%, 0.4%, 0.5% (w/w). Extracted permanent premolar teeth were cleaned and stained with tea and coffee solutions. Formulations of S. persica fiber paste were then used to brush the teeth and being compared to commercial whitening toothpaste. The teeth shade changes were evaluated using VITAPAN® Classical Shade. After brushing under standardized condition using a brushing simulator machine, it was found that the staining of teeth buccal surface was reduced at least one tone of shade according to the VitaPan® shade.

Effect of triggering angles on the crushing mechanisms of hybrid woven kenaf/aluminum hollow cylinders

This paper presents the effect of triggering angles constructed on the top of hybrid woven kenaf/aluminium hollow cylinders on the energy absorption performances. The crushing performances of aluminium tubes can be found widely in open literature. However, lack number of work on the hybridizing the aluminium tubes with woven kenaf fibre is found. Woven kenaf mats are produced and bathed with polymeric resin before they are wrapped around the aluminium tubes twice. Different fibre orientations, +-θ° are used where θ = 0, 15, 30 and 45. Once the hybrid composite hardened, one of their end are chamfered using different angles of 0o, 30o, 45o and 60o. The tubes are quasi-statically compressed in order to obtain their force-displacement responses and crashworthiness parameters are extracted and discussed with the relation of fibre orientations and chamfering angles. It is found that the chamfering angles are only affected the force-displacement curves during the first stage of elastic deformation whereas there is no obvious effect in the second stage. However, varying the fibre orientations are slightly increased the force-displacement curves especially when the fibre is orientated with 30o. Based on the fracture mechanism observations, most of composite experienced large fragmentation indicating that the composites absorbed the crushing energy ineffectively.

Technology Model of Aquaculture Production System

The high market demand has led to the rapid growth in fish farming. The young generation are inexperienced in determining the estimated results of fish farming and the preparation of fish pond during the period of fish farming. These need a complete guide as their reference which includes the knowledge of fish farming. The main objective of this project is to develop a practical design of real pond appropriate with aquaculture technology and fish farming production. There are three parts of study in this project which include fish farming cage, growth of fish and water quality of fish farming pond. Few of experiments were carried out involved the collection data in terms of growth of fish and parameters of water quality.

Improvement of automatic fish feeder machine design

Nation Plan of action for management of fishing is target to achieve an efficient, equitable and transparent management of fishing capacity in marine capture fisheries by 2018. However, several factors influence the fishery production and efficiency of marine system such as automatic fish feeder machine could be taken in consideration. Two latest fish feeder machines have been chosen as the reference for this study. Based on the observation, it has found that the both machine was made with heavy structure, low water and temperature resistance materials. This researchs objective is to develop the automatic feeder machine to increase the efficiency of fish feeding. The experiment has conducted to testing the new design of machine. The new machine with maximum storage of 5 kg and functioning with two DC motors. This machine able to distribute 500 grams of pellets within 90 seconds and longest distance of 4.7 meter. The higher speed could reduce time needed and increase the distance as well. The minimum speed range for both motor is 110 and 120 with same full speed range of 255.