Mohd Zamri Hasan

Analysis the Condition of RazakSAT Based on Attitude Sensor of Atttitude Determination System Data

Attitude determination system (ADS) is a process to control the orientation of the satellite to make sure that the orientation is relative to inertial references frame such as Earth. ADS is consists of mathematical algorithm and sensor as a references measurement to determine attitude of satellite. Since RazakSAT in the orbit, the sensor such as sun sensor, magnetometer and gyroscopes are used to control angular rotation and prevent high spin rates that can damage the satellite. This paper presents the analysis on sensor of attitude determination system based on RazakSAT data. Matlab was used to analyze the X,Y and Z axis of the sensor to determine the condition of the satellite.

A study on correlation between ECI and satellite’s velocity based on RazakSAT data

This paper presents the analyzed on Earth Centered Inertial (ECI) of Attitude Determination System (ADS) and satellite velocity data of RazakSAT by using analysis method. ADS are one sub-system in satellite as function to control the orientation of satellite relative with inertial references frame. ECI is one of inertial references frame of RazakSAT with three dimension axis. ECI and velocity of satellite data of RazakSAT are analyzed with normality test by using Minitab software. The results show ECI and velocity data of RazakSAT are non-normal distribution, and correlation between ECI and satellite velocity is ellipse shape.

A double layer neural network for solving mixed-integer quadratic optimization problems

The main aim of this paper is to propose a double layer neural network (DLNN) for solving a class of mixed-integer quadratic optimization problems. It is proven that the DLNN is globally stable in the sense of Lyapunov and the output of the proposed neural network converged globally to an optimal solution. Compared with conventional Boltzmann Machine (BM) neural networks, the proposed neural network has a very small model size owing to its double layer structure. Furthermore, an application to power system showed that DLNN is effective. Numerical results shows that the DLNN is reduced by up to one-fifth compared to BM neural networks.

Unmodeled disturbances torque exerted on RazakSAT’s attitude during sun tracking mode

In space, environmental torques exerts continuously on a satellite and may influence and affect the satellite’s attitude dynamics. The relative strength of the various torques will depend on both spacecraft environment and the structure of the spacecraft itself. RazakSAT is the world first remote sensing satellite launched into Near Equatorial Orbit (NEqO). Hence, the objective of this paper is to study the properties and behaviour of disturbance torque that perturb RazakSAT’s attitude during orbiting in NEqO in sun tracking mode using in-flight attitude data. The results show that the environmental torques exerted on RazakSAT during sun tracking mode is periodic and the magnitude of the torques vary from 10−4 to 10−7. Understanding the behaviour of disturbance torque can be utilized in spacecraft design to improve the satellite’s performance for future mission.

Development of a Monitoring System for Timah Tasoh Dam

Timah Tasoh serves as a source of drinking water and industrial supplies, irrigation, tourism, as well as flood mitigation for the state of Perlis. However, the dam is also become one of the causes of flooding in the state and it gives a terrible consequences resulting in losses of various aspects. Therefore, to overcome this problem, an automated control system and monitoring system have been developed for controlling the operation and monitoring the status of the service spillway gates at Timah Tasoh dam. The system was developed by using the programmable logic controller (PLC) for controlling the operation of the spillway to release the water out of the dam at the rate prescribed and graphical user interface (G.U.I) for the spillway gate status monitoring purpose. The program developed involves the control of six spillway gates in stages depending on water level in the dam. The operations of controlling and monitoring the spillway gates then were tested through the simulation in order to see whether the system operated as required.

Structural Learning of Boltzmann Machine and its Application

In order to solve a problem efficiently, we propose the structural learning of Boltzmann machine. The proposed method enables us to solve the problem defined in terms of mixed integer quadratic programming. In this research, an analysis is performed by using the concepts of the reliability and risks of units evaluated using a variance-covariance matrix and also the effect and expanses of replacement are measured. Mean-variance analysis is formulated as a mathematical programming with two objectives to minimize the risk and maximize the expected return. Finally, we employ a Boltzmann machine to solve the mean-variance analysis efficiently. At the end, the result of our method was exemplified. This method enables us to obtain a more effective selection of results and enhanced the effectiveness of the decision making process.

Accurate phase to phase fault resistance calculation using two terminal data

Faults can occurred at the transmission line due to lightning strike, broken conductor, cross arm or tower falls, danger tree, crane or animal encroachment, polluted insulator etc. Each type of fault will represents a fault resistance value. Fault resistance will affects the accuracy of protection relays in fault location and fault zone detection. Phase to phase fault is one type of unsymmetrical fault at the transmission line. This paper represents the accurate way to calculate the actual phase to phase fault resistance value by using data from both local and remote substations. From the finding, the actual fault resistance can be represented by fault resistance as seen from local substation in parallel with the fault resistance as seen from remote substation. To prove the finding, simulation has been carried out and the results show the validity of the proposed theory.