Leow Wai Zhe
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Preferred name
Leow Wai Zhe
Official Name
Wai Zhe, Leow
Alternative Name
Leow, Wai Zhe
Leow, W. Z.
Zhe, Leow Wai
Zhe, L. W.
Main Affiliation
Scopus Author ID
56178375200
Researcher ID
DXJ-9302-2022

Research Output

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  • Publication
    Analysis on the Effect of DC Current Changes on the Magnetic Field of Wireless Power Transfer
    ( 2023-01-01)
    Muhammad Irwanto Misrun
    ;
    Ali M.B.
    ;
    Nugraha Y.T.
    ;
    Baharuddin Ismail
    ;
    Nisja I.
    ;
    Leow Wai Zhe
    The generation of electromagnetic radiation in a solenoid, driven by alternating current (AC) voltage, is directly influenced by the voltage and current flowing through the solenoid. Exploiting this concept, wireless power transfer (WPT) systems can be developed. These systems consist of a sending coil and a receiving coil, both equipped with solenoids. The sending coil is connected to a half bridge circuit to generate AC voltage, which is then transmitted to the receiver coil. In this study, the effects of various factors on the performance of the wireless power transfer system were investigated, with a particular focus on the impact of DC voltage and input DC current. To examine these effects, an experimental setup was employed where the transmitter and receiver coils were powered by a DC voltage source. By varying the voltage and current parameters, the study aimed to analyze their influence on the wireless power transfer process. The simulation results show that 100 V and 150 V of DC current will produce 36.54 A and 54.8 A of input DC current respectively with constant resistor 7.54×10-2 Ω. The result shows that the input DC current is directly proportional with the magnetic field, AC current at sending and receiving coil, voltage at sending and receiving coil and AC power at receiving coil. Increasing the input DC current will increase the magnetic field, AC current at sending coil and receiver coil, voltage at transmitter coil and receiving coil and AC power at receiving coil and vice versa.
      1  23
  • Publication
    A review of detecting outlier in a circular regression model
    ( 2020-03-20)
    Ramlee, Intan Mastura
    ;
    Safwati Ibrahim
    ;
    Leow Wai Zhe
    ;
    Mohd Irwan Yusoff
    Circular data is very relevant and important application technique in many fields such as physical science, medical science and others. During the last few years, writers have shown a deep interest of outlier detection in the circular regression model. In this case, authors have a tendency to study and explore in detail about the outlier detection in circular regression model. This paper aims to review the outlier detection methods in circular regression model. Here, we concentrate the attention on the methods of identifying outlier in this model. These survey of circular regression models in which many interesting properties and is good enough to detect the occurrence of outlier. Through the survey may highlight the significant of methods to detect outliers in circular regressions model and provide guideline for future work to look into the research gap.
      2  24
  • Publication
    Synchronized cell balancing charging of supercapacitors using PI control
    (IOP Publishing, 2020)
    M.A Rashed
    ;
    Muhammad Izuan Fahmi Romli
    ;
    M M Azizan
    ;
    C L Wai
    ;
    Leow Wai Zhe
    ;
    N F Rosle
    This paper covers the synchronized cell balancing charging of supercapacitors using pi control. The main objective of this project is to design a balanced circuit for supercapacitor and balance the voltage for each supercapacitor in series using pi control. This project aims to introduce a switch resistor design for a supercapacitor to balance the cell. Due to its low cost, easy to implement, and charge/discharge, the switch resistor design was chosen as the balanced circuit. The switch resistor design process was accomplished taking into account all the calculation for the design parameters. Using the pi control given to the circuit the stability and balancing in the voltage. The pi control design process was accomplished with the calculation for the design parameters.
      11  1
  • Publication
    Comparative Study of Three Methods for Determining Weibull Parameters in Pauh Putra, Perlis
    ( 2021-06-11)
    Thiraphorn B.L.
    ;
    Leow Wai Zhe
    ;
    Mohd Irwan Yusoff
    ;
    Safwati Ibrahim
    ;
    Muhammad Irwanto Misrun
    ;
    Kumuthawathe Ananda-Rao
    ;
    Amelia A.R.
    This paper studied about analysis characteristics of wind speed at Pauh Putra, Perlis, where nearest to Chuping station, Perlis, Malaysia. The wind speed characteristics consist of monthly and annual wind speed in Perlis, Malaysia. By using Weibull distribution, three different methods to calculate the potential of wind power generation and analysis the characteristics of wind speed at Pauh Putra, Perlis. The results present the means wind speed is 1.0790 m/s and 1.1321 m/s for 2018 and 2019, respectively. The highest monthly mean wind speed occurred in February for both years, 2018 and 2019. Besides, the lowest monthly wind speed for 2018 in May and for 2019 in October. The Weibull distribution summarized the highest probability density is 120% in the wind speed, 1.1 m/s using the Maximum Likelihood Method (MLM) method for these two years. Furthermore, this research found that the Energy Pattern Factor (EPF) Method is stretched to the right, and its height decreased from other methods for both years based on the graph of the wind speed of probability density function. The Maximum Likelihood Method (MLM) for these two years is higher because its shape parameters are relatively higher based on the graph of the wind speed of probability density function.
      30  1
  • Publication
    Assessment of wind power potential in the North region of Malaysia, Chuping Perlis
    ( 2023-01-01)
    Thiraphorn Bun Leew
    ;
    Leow Wai Zhe
    ;
    Mohd Irwan Yusoff
    ;
    Safwati Ibrahim
    ;
    Tan Xiao Jian
    ;
    Muhammad Irwanto Misrun
    ;
    Kumuthawathe Ananda-Rao
    The wind turbines is a main device that convert the kinetic energy from blades to electrical energy. Before installing wind turbines, the Weibull probability distribution must be calculated to determine the certain wind speed probability. Many problems will come if there no analysis the characteristics of wind in selected location, such as wind speed that not suitable for building wind farm to supply the population in that area. Shape and scale factors, which be controlled in a variety of ways, influence the Weibull distribution. Many studies have looked into which of the various Weibull parameter estimation methods is the most dependable. However, because the results of these investigations were inconsistent, research into more trustworthy Weibull parameter estimation methods is still ongoing. An analysis of data collected Chuping, Perlis for two years was conducted in this study (from 2018 to 2019). By using statistical analysis to evaluate the Weibull distribution method, this study used three methods to compared the Weibull parameters and identified the most reliable and effective method to obtain the Weibull probability distribution by using a three approach that compares the variances of RMSE, MSE and R2, which provides comprehensive insight into level error and volatility. Modified maximum likelihood method, graphical method, and power density method are the three methods used in this study. Therefore, the graphical method has the best accuracy in the wind speed distribution prediction, several methods such as the modified maximum likelihood method, and the power density method have the worst prediction of the wind speed distribution based on all the statistical method variances for this region.
      7  25
  • Publication
    Breast cancer status, grading system, etiology, and challenges in Asia: an updated review
    (De Gruyter Brill, 2023)
    Tan Xiao Jian
    ;
    Cheor Wai Loon
    ;
    Cheng Ee Meng
    ;
    Khairul Shakir Ab Rahman
    ;
    Wan Zuki Azman Wan Muhamad
    ;
    Leow Wai Zhe
    The number of breast cancer incidences reported worldwide has increased tremendously over the years. Scoping down to Asia, in 2020, the reported incidences of breast cancer are appalling, comprising 1,026,171 cases, occupying up to 45.4% of cases across the globe. Breast cancer is a non-communicable disease, that emerges in variegated forms, self-subsistent, and the etiology is observed to be multifactorial, dependent on the individual reproductive pattern, hormonal factors, diet, physical activity, lifestyle, and exposure to certain advent procedures. Given this complexity, breast cancer is expected to undergo a persistent increment in the number of incidences in near future, exacerbating the public health quality, regardless of race, ethnicity, geographical subgroups, and socioeconomic. In this review article, the authors examine breast cancer in multiple facets, comprising the updated statistics on breast cancer, typically in Asia; etiology of breast cancer; diagnosis of breast cancer; grading system; and challenges in breast cancer from the country’s income perspective. Realizing the ever-increasing demand for quality treatment, here, the article also contemplates common therapies in breast cancer, such as breast-conserving therapy, mastectomy, postmastectomy radiation therapy, neoadjuvant chemotherapy, axillary surgery, chemotherapy, adjuvant medical therapies, biological and targeted therapies, and endocrine therapy. This review article intended to provide a brief yet broad panoramic view of breast cancer, to readers, ranging from newcomers, existing researchers, and relevant stakeholders in the topic of interest.
      1  2
  • Publication
    Performance power evaluation of DC fan cooling system for PV panel by using ANSYS CFX
    ( 2017-09-26)
    Nur Syafiqah Zhubir
    ;
    Nasrul Amri Mohd Amin
    ;
    Mohd Irwan Yusoff
    ;
    Muhammad Irwanto Misrun
    ;
    Leow Wai Zhe
    ;
    Amelia A.R.
    A research has been conducted to find the optimum combination for DC fan air cooling system of photovoltaic (PV) panel. During normal operation of PV panel, it is estimated that only 15 % of solar radiation is converted into electrical energy. Meanwhile, the rest of the solar radiation is converted into heat energy which affects the performance of the PV panel. Therefore, the aim of this research is to investigate the performance power evaluation of DC fan cooling system for PV panel by using ANSYS CFX. The effect of airflow configuration of DC fan has been investigated. This is to analyze whether the airflow circulation of DC fan cause a change towards the maximum temperature of PV panel. Besides, the impact of varying number of DC fans attached at the back of PV panel is evaluated. The result of airflow circulation of DC fan has been discussed. Meanwhile, with the increment number of DC fans, the PV panel temperature drops significantly. As a conclusion, the optimum number of DC fans is two with the combination of inlet airflow.
      1  30
  • Publication
    A Potential Controller for Smart Electrical Energy Management System
    ( 2021-06-11)
    Kumuthawathe Ananda-Rao
    ;
    Mohd Alif Ismail
    ;
    Afifah Shuhada Rosmi
    ;
    Leow Wai Zhe
    ;
    Surina Mat Suboh
    ;
    Muhammad Izuan Fahmi Romli
    ;
    Abdullah A.M.
    Integrated energy utilization has been recognized as a productive way towards better energy management, besides increasing Renewable Energy (RE) penetration. Thus, the combination of RE integrated with the Battery Energy Storage System (BESS) has been recognized as the primary solution where it is necessary to have a controller to interface the system efficiently. Hence, a smart electrical energy management system controller is designed and developed based on load leveling and peak shaving applications for real-time AC power management in this work. The main function of the controller is to continuously monitor and maintain the load demand and to produce a leveled or shaved load profile that will be seen at the grid network by controlling the battery operation. The testing results concluded that the controller able to perform both the energy applications. Overall, a dual function controller based on energy applications to maintain consumer load demand usage more securely and reliably, so that the utility bill is reduced and the battery lifetime is prolonged simultaneously is achieved in this work.
      9  28
  • Publication
    Improvement of the photovoltaic output performance using hybrid active and passive cooling system
    ( 2017)
    Leow Wai Zhe
    This thesis presents the improvement of the photovoltaic (PV) output performance using hybrid active and passive cooling system. The PV technology has been used for several years and has proven successful for power generation, but the challenge is to adapt to local environment conditions, mainly caused by changes in weather conditions. Furthermore, the output power of the PV panel decreases as the operating temperature of the PV panel increases. Therefore, the main purpose of this current research is to design various types of cooling system in order to improve output power of the PV panel. This study has four specific objectives. Firstly, the effects of weather conditions on the thermal behaviour of PV panels were studied using simulation and experimental methods. In the simulation study, the effect of weather conditions in the thermal behaviour of the PV panel was simulated using CATIA and ANSYS simulation software. This study was conducted based on the weather of Centre of Excellence for Renewable Energy (CERE), UniMAP, Malaysia. It was shown that as solar irradiance and ambient temperature increased, the operating temperature of the PV panel increased. As the wind speed increased, the operating temperature of the PV panel decreased. In the experimental study, the dust appearing on the surface of the PV panel resulted in a decrease in the performance of the PV panel. However, the presence of wind on the surface of the PV panel resulted in an increase in the performance of the PV panel. Secondly, the PV panels with various types of cooling system were designed and simulated using ANSYS simulation software in order to analyse their thermal behaviour under weather conditions of CERE, Perlis. This included direct current (DC) fan cooling system, DC water pump cooling system, paraffin wax cooling system, hybrid DC water pump and paraffin wax cooling system as well as hybrid DC water pump and DC fan cooling system. The results showed that the PV panel with hybrid DC water pump and DC fan cooling system has the lowest operating temperature of 35.43 °C compared to other PV panels.
      16  13
  • Publication
    UHF Sensors for On-line Partial Discharge Detection on Power Transformer: Hilbert fractal, Moore Fractal and Peano fractal
    ( 2020-12-11)
    Alleef Abd Jalil, Muhammad
    ;
    Afifah Shuhada Rosmi
    ;
    Mohamad Nur Khairul Hafizi Rohani
    ;
    Muzamir Isa
    ;
    Roslizan N.D.
    ;
    Leow Wai Zhe
    ;
    Mohd Aminudin Jamlos
    Partial discharge (PD) is the causes of the fault to occur in high voltage equipment due to the breakdown of the insulation system happen on equipment, even old equipment or new equipment. The PD in transformer oil is one of the significant causes of insulation failure and a breakdown. Hence, a sensor is needed to continuously monitor and detect the PD at an early stage on the power transformer. An antenna is one of the sensors that can be used to detect PD based on ultra-high frequency (UHF) method. However, the size of the antenna is the main problem to be installed in the transformer tank. Thus, three types of antenna which are Moore, Hilbert and Peano fractal with the dimension of 10 X 10 cm is designed to operate in UHF range 0.3 GHz to 3 GHz to be able to detect the frequency of partial discharge signal generated by electromagnetic waves. The performance of the proposed antennas in terms of return loss, Voltage Standing Wave Ratio (VSWR) and radiation pattern are analysed and compared for PD detection on the power transformer. Based on the result, the fourth-order of Hilbert fractal antenna was found to be the best antenna for PD detection in power transformer at working frequency range from 0.72 GHz to 2.77 GHz. This antenna also has low threshold of return loss at-36.2 dB for the resonant frequency at 1.67 GHz and the value of VSWR is near to one which is 1.03. Lastly, the radiation pattern of this antenna is almost in hemisphere shape and the gain variation of all frequencies are nearly stable compared to the other types of antenna.
      7  23