Siti Hajar Yusoff

International Islamic University Malaysia

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Nur Shahida Midi

International Islamic University Malaysia

Ahmed Samir Badawi

Qatar Science and Technology Park

Mohd Shahrin Abu Hanifah

International Islamic University Malaysia

Sheroz Khan

University of Amsterdam

Teddy Surya Gunawan

International Islamic University Malaysia

Siti Nadiah Mohd Sapihie

Petronas (Malaysia)

Sarah Yasmin Mohamad

International Islamic University Malaysia

Mohamed Hadi Habaebi

International Islamic University Malaysia

Nurul Fadzlin Hasbullah

International Islamic University Malaysia

Alhareth Zyoud

Birzeit University

Cooperative Institutions

International Islamic University Malaysia

International Islamic University, Islamabad

University of Kuala Lumpur

National University of Malaysia

Universiti Teknologi MARA

University of Malaya

Array Information Technology (United States)

Universiti Sains Malaysia

Universiti Tenaga Nasional

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Observation on Geomagnetic Field from MAGDAS (PEN) and INTERMAGNET (DAL) Stations in Equatorial Region

S. Selvakone Siti Hajar Yusoff Nur Awatiff Mohamad Rizal Nasriah Zakaria Akimasa Yoshikawa

International Real-Time Magnetic Observatory Network (INTERMAGNET) and Magnetic Data Acquisition System (MAGDAS) are ground-based magnetometer networks developed to study the space weather and monitor the geomagnetic variations. A MAGDAS-II type magnetometer was installed at Penang recently for seismic monitoring. The MAGDAS (PEN) station is newly established, the reliability of the magnetometer had to be tested. The test is conducted by comparing its data with geomagnetic data obtained from another well-established magnetometer system. Therefore, this research is conducted to study the reliability of the newly installed MAGDAS system by comparing geomagnetic data with the INTERMAGNET system. The closest INTERMAGNET station that was chosen for this study is Dalat, Vietnam. The available data from November 2019 to July 2020 are selected to analyse the geomagnetic components H, D, and Z variations obtained from both stations. The result of the variations will be discussed briefly in the result and discussion part of this paper. The variations of the geomagnetic component of the newly installed MAGDAS magnetometer are verified to be reliable data for the geomagnetic field monitoring.

Space Weather

10.1109/iconspace53224.2021.9768740

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Design of U and I Ferrite Core On Dynamic Wirelesss Charging for Electric Vehicle

Amira Aziera Abdullah Siti Hajar Yusoff Erwan Sulaiman Nur Shahida Midi Ahmed Samir Badawi

This study provides an approach investigation of U and I ferrite core geometrics to improve the power efficiency for Electric Vehicle (EV) inductive wireless charging in dynamic mode. Dynamic wireless charging (DWC) enables recharging of battery pad during the vehicle is on the road. Hence, the design of battery pad must deal with two main factor that led to power leakage such air gap and misalignment. Using ferrite magnetic core, it improves the power transferred by reduce the leakage magnetic radiation between primary and secondary side. Different conditions are investigated on U and I core. The first and second condition is U or I core only at primary side and secondary U or I core only at the secondary side. The last condition is both at primary and secondary side of U or I ferrite core. The purpose of this project is to design a prototype of EV thru several method, design proposed, circuit simulation, pair simulation and prototype development. NI Multisim are used to simulate circuit of WPT for operation validity.

Ferrite core

10.1109/iccce50029.2021.9467217

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Data bank: nine numerical methods for determining the parameters of weibull for wind energy generation tested by five statistical tools

International Journal of Power Electronics and Drive Systems/International Journal of Electrical and Computer Engineering (2021)

Ahmed Samir Badawi Siti Hajar Yusoff Alhareth Zyoud Sheroz Khan Aisha Hassan Abdalla Hashim

This study aims to determine the potential of wind energy in the mediterranean coastal plain of Palestine. The parameters of the Weibull distribution were calculated on basis of wind speed data. Accordingly, two approaches were employed: analysis of a set of actual time series data and theoretical Weibull probability function. In this analysis, the parameters Weibull shape factor ‘k’ and the Weibull scale factor ‘c’ were adopted. These suitability values were calculated using the following popular methods: method of moments (MM), standard deviation method (STDM), empirical method (EM), maximum likelihood method (MLM), modified maximum likelihood method (MMLM), second modified maximum likelihood method (SMMLM), graphical method (GM), least mean square method (LSM) and energy pattern factor method (EPF). The performance of these numerical methods was tested by root mean square error (RMSE), index of agreement (IA), Chi-square test (X2), mean absolute percentage error (MAPE) and relative root mean square error (RRMSE) to estimate the percentage of error. Among the prediction techniques. The EPF exhibited the greatest accuracy performance followed by MM and MLM, whereas the SMMLM exhibited the worst performance. The RMSE achieved the best prediction accuracy, whereas the RRMSE attained the worst prediction accuracy.

10.11591/ijpeds.v12.i2.pp1114-1130

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Citations (7)

Design and Performance Analysis of Flexible Microstrip Patch Antenna with Rubber Substrate

Ahmad Alhadi Ruslan Sarah Yasmin Mohamad Norun Abdul Malek Siti Hajar Yusoff Siti Normi Zabri

This paper designs a microstrip patch antenna using rubber substrate with different concentration of carbon filler which are rubber with 0% carbon filler (Natural Rubber), rubber with 20% of carbon filler, rubber with 25% of carbon filler and rubber with 50% of carbon filler. The performance of the antennas designed are analyzed and compared with other commonly proposed flexible substrate which are Polydimethylsiloxane (PDMS) and RO3003. The performance of the antennas is compared based on the return loss of the antenna, bandwidth of the antenna and gain of the antenna. The effect of antenna bending to the performance of the antenna are also executed in this paper. Different bending angle in term of the cylindrical radius are applied to the antenna to further study the impact of the bending to the performance of the antenna.

Patch antenna

Return loss

10.1109/iccce50029.2021.9467175

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LoRa LPWAN Propagation Channel Modelling in IIUM Campus

Nurul Afifah Binti Masadan Mohamed Hadi Habaebi Siti Hajar Yusoff

LoRa, one of the most outstanding low power wide area network (LPWAN) technology has unique and remarkable features. Because of its long-range coverage, low power consumption and low cost system architecture, Lora WAN has becoming a favorable option for performing communication in most of IoT wireless applications. This project aimed at quantifying the foliage effect in terms of attenuation and its overall contribution to the path-loss and link budget calculations. Specifically, five tree types were studied and their contribution to the path loss were quantified for different path crossings (e.g., trunk, tree-top and branches). The trees are Licuala Grandis, Mimusops Elengi, Mangifera Indica, Cyrtostachys Renda and Livistona Chinensis. Mimusops Elengi tree, characterized by its big size and crown density, gave the strongest mean foliage attenuation accumulating up to 20 dB. Trunks contribute even higher attenuation in comparison to tree-tops and branches. The Okumura/Hata, Log-normal shadowing and foliage models are used as references for this propagation models development. Our study showed that Okumura fails to capture the effect of foliage in International Islamic University Malaysia, Gombak campus that is rich in trees. This goes to illustrate the necessity for considering the tropical environment where the characterization of foliage attenuation plays an important role in determining the propagation model path-loss and link budget needed for LoRa network design and planning.

Link budget

LPWAN

Averrhoa carambola

Mangifera

Tree (set theory)

10.1109/iccce.2018.8539327

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Citations (17)

Smart Meter Based on IoT Platform

Muhammad Sharir Fathullah Mohd Yunus Siti Hajar Yusoff Siti Nadiah Mohd Sapihie Nur Syazana Izzati Razali

The manual nature of the classic energy meter has rendered it useless in the Internet of Things (IoT) era. It is not only a waste of time, but it is also not systematized. The traditional energy metering method is cumbersome and inefficient. A creative and essential solution is necessary to keep up with technological changes. This aligns with Malaysia's vision of becoming a developed country by 2020. The introduction of smart meters has completely changed how energy is measured. Smart meters automate procedures and increase efficiency throughout the entire system. Utility workers no longer need to visit each house to collect energy consumption data for billing purposes. Smart meters, on the other hand, give consumers access to real-time data on energy consumption, enabling them to monitor and manage their electricity usage. The goal of this project is to create a smart meter that is just as functional as other smart meters on the market with faster time intervals as the market smart meter takes 30 minutes to update real-time data. The proposed smart meter, which is built on an IoT platform, automates the entire process by sending data to the utility provider via IoT technology and obviating the need for in-person visits. The utility company can then analyze the data and generate accurate bills for each user. The design will also integrate extra functions like meter tampering detection. Hardware development, programming, and circuit design are all included in this project. With Arduino Uno serving as the system's microprocessor, the smart meter will operate effectively and dependably

Smart meter

Automatic meter reading

Electricity meter

Arduino

Metering mode

Microprocessor

10.1109/iccce58854.2023.10246032

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Citations (1)

Discharge current distribution in stratified soil under impulse discharge

IOP Conference Series Materials Science and Engineering (2017)

Fawwaz Eniola Fajingbesi Nur Shahida Midi Elsheikh Mohamed Ahmed Elsheikh Siti Hajar Yusoff

The mobility of charge particles traversing a material defines its electrical properties. Soil (earth) have long been the universal grounding before and after the inception of active ground systems for electrical appliance purpose due to it semi-conductive properties. The soil can thus be modelled as a single material exhibiting semi-complex inductive-reactive impedance. Under impulse discharge such as lightning strikes to soil this property of soil could result in electric potential level fluctuation ranging from ground potential rise/fall to electromagnetic pulse coupling that could ultimately fail connected electrical appliance. In this work we have experimentally model the soil and lightning discharge using point to plane electrode setup to observe the current distribution characteristics at different soil conductivity [mS/m] range. The result presented from this research indicate above 5% shift in conductivity before and after discharge which is significant for consideration when dealing with grounding designs. The current distribution in soil have also be successfully observed and analysed from experimental result using mean current magnitude in relation to electrode distance and location, current density variation with depth all showing strong correlation with theoretical assumptions of a semi-complex impedance material.

Soil resistivity

10.1088/1757-899x/210/1/012057

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Development and Testing of a USM High Altitude Balloon

Journal of Physics Conference Series (2018)

Ahmad Shaqeer Mohamed Thaheer Norilmi Amilia Ismail Siti Hajar Yusoff Muhammad Azwan Nasirudin

This paper discusses on tests conducted on the component and subsystem level during development of the USM High Altitude Balloon (HAB). The tests conducted by selecting initial components then tested individually based on several case studies such as reliability test, camera viewing, power consumption, thermal capability, and parachute performance. Then, the component is integrated into sub-system level for integration and functionality test. The preliminary result is utilized to tune the components and sub-systems and trial launch is conducted where the sample images are recorded and atmospheric data successfully collected.

Component (thermodynamics)

Integration testing

Sample (material)

10.1088/1742-6596/1005/1/012048

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Machine Learning-Based Stress Level Detection from EEG Signals

Ali Nirabi Faridah Abd Rahman Mohamed Hadi Habaebi Khairul Azami Sidek Siti Hajar Yusoff

Recent statistical studies indicate an increase in mental stress in human beings around the world. Due to the recent pandemic and the subsequent lockdowns, people are suffering from different types of stress for being jobless, financially damaged, loss of business, deterioration of personal/family relationships, etc. Stress could be a severe factor for many common disorders if experienced for a long time. Stress is associated with the brain activities of human beings that can be scanned by electroencephalogram (EEG) signals which is very complex and often challenging to understand the signal's pattern. This paper presented a system to detect the stress level from the EEG signals using machine learning algorithms. The proposed method, at first, removed physiological noises from the EEG signal applying a band-pass FIR filter. A discrete wavelet transform (DWT) method was used for features extraction from the filtered EEG signal. The features were classified using a set of classifiers those are k-nearest neighbors (kNN), support vector machine (SVM), Naïve Bayes, and linear discriminant analysis (LDA). Two levels of stressed EEG data were considered and found the classification accuracy of 86.3%, 91.0%, 81.7%, and 90.0%. The highest classification accuracy, the SVM classifier, outperforms the current state of the art by 15.8%.

10.1109/icsima50015.2021.9526333

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Citations (6)

Predictive Control of AC/AC Matrix Converter

International Journal of Power Electronics and Drive Systems/International Journal of Electrical and Computer Engineering (2017)

Siti Hajar Yusoff Nur Shahida Midi Sheroz Khan Majdee Tohtayong

This work investigates the usage of Model Predictive Control (MPC) for a three phase conventional matrix converter with low pass filter at the input and output side. The conventional matrix converter has 3 input and 3 output which gives 27 switching state. From this design, a MPC is incorporate to control the output voltage and the input currents for all the phases. The design of the proposed controller is based on the input current controller and output voltage controller with load observer. The proposed MPC using cost function will select the minimized switching state to be applied to next switching. This gives a sinusoidal output voltages and input currents. A simulation and experimental studies are presented to validate the proposed control scheme.

Observer (physics)

Model Predictive Control

Three-phase

Matrix (chemical analysis)

10.11591/ijpeds.v8.i4.pp1932-1942

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Citations (10)