Nur Hafizah Ghazali
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Preferred name
Nur Hafizah Ghazali
Official Name
Nur Hafizah Ghazali, Ghazali
Alternative Name
Ghazali, Nur Hafizah
Ghazali, N. H.
Ghazali, N.
Main Affiliation
Scopus Author ID
36104136600

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Characterization of all-optical Tofolli and Peres gates employing optimized SOA-NOLM

2020-01-08 , Nur Hafizah Ghazali , Mohamad Halim Abd. Wahid , Nor Azura Malini Ahmad Hambali , Nurjuliana Juhari , Zahari S.M. , Shahimin M.M.

In this work, all-optical reversible gates namely Tofolli and Peres are studied and characterized. The gates utilize semiconductor optical amplifier (SOA) in nonlinear loop optical mirror (NOLM). The reversible gates are performed at data rate 10 Gb/s with narrow Gaussian pulses as input signals. Delay of 130 ps and injection current of 170 mA have displayed the optimum outputs in the SOA-NOLM. Extinction ratio is greatly reduced, thus less noise interferes the logic operation in this simple technique. It is observed that Peres gate has shown a higher output power compare to Toffoli gate. This could be due to multiple amplification that are experienced by the signals. Other than the gain, injection current and delay are shown to give major effect in producing the correct bits at the outputs. The SOA-NOLM also can be cascaded for other arithmetic signal processing operation at high frequency. It is also recorded that the design consumes low power especially in small signal gain process. Thus, the design indicates its versatility to be executed in photonic integrated circuits for ultrafast signal control through fiber networks.

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A new optimization strategy for wind/diesel/battery hybrid energy system

2022-01-15 , Aziz A.S. , Mohammad Faridun Naim Tajuddin , Hussain M.K. , Mohd Rafi Adzman , Nur Hafizah Ghazali , Ramli M.A.M. , Khalil Zidane T.E.

HOMER software is a powerful tool for modeling and optimization of hybrid energy system (HES). The main two default control strategies in HOMER are load following (LF) and cycle charging (CC) strategies. In these strategies, the decision to use the generator or battery at each time step is made based on the lowest-cost choice. Therefore, these strategies are difficult to be implemented in practice especially in countries with continuous fuel price fluctuations. In this study, a new dispatch strategy based on HOMER-MATLAB Link Controller for an isolated wind/diesel/battery HES is proposed to overcome the limitations of the default HOMER strategies. A detailed technical, economic, and greenhouse gas emission analysis is presented for the system under LF, CC, and the proposed dispatch strategies. Besides offering more realistic optimization, the results show that the proposed strategy offers the best economic and environmental performance with a net present cost of $56473 and annual CO2 emissions of 6838 kg. Furthermore, the sensitivity analysis reveals that the proposed strategy is not affected by the fuel price variation, in opposite to LF, and CC strategies which is affected dramatically by this variation. The findings are of paramount importance towards more realistic and efficient energy management strategies.

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Design and analysis of small scale oyster mushroom cultivation

2024-02-08 , Zahereel Ishwar Abdul Khalib , Nur Hafizah Ghazali , Mohamed Elshaikh Elobaid Said Ahmed , Tai W.J. , Letchumanan N. , Azman N.F.F. , Rodhi M.N.Q.

Cultivators that grow oyster mushrooms keep failing due to a of lack control in temperature, humidity, soil moisture, and concentration of carbon dioxide. In order to grow great oyster mushrooms and avoid crop failure, the temperature must be between 22°C to 28°C and the relative humidity must be between 85% to 90%. The concentration of carbon dioxide (CO2) needs to be controlled below 800 during its growth phase. Failure to meet those parameters will result in the mushroom drying out, slowing growth, or stopping. As a result, oyster mushroom cultivators will require a system that can control the surrounding temperature and humidity, soil moisture, and concentration of CO2 conditions in order to produce good-quality oyster mushrooms. An automated environmental control system is constructed to handle the problem. In this system, by means of a feedback control loop system that monitors and activates the actuators when necessary, promising results of the oyster mushroom cultivation system are produced and analyzed.

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Undergraduates’ learning habits amid COVID-19 pandemic: a pilot study

2020 , Nurulhuda Ghazali , Nurul Hidayah Mat Zain , Siti Feirusz Ahmad Fesol , Mastura Mansor , Maswati Suffian , Nur Hafizah Ghazali

The spread of Coronavirus disease (COVID-19) over the world has prompted a new wave of online learning in higher education. Regardless of the preparation for both educators and students, the online teaching and learning proceed to ensure a running institution. This sudden change of environment has caused a significant interruption in students’ learning. Thus, this study investigated the effects of COVID-19 pandemic on students’ performance based on their learning habits. A quantitative method was used to collect data from undergraduates with different sociodemographic and psychological attributes. The empirical evidence of this study could be utilized to develop a prediction model that is able to predict the students’ performance and a set of relevant features that contribute to student’s performance. The results also could be a foundation for higher education departments to produce more sustainable regulations and policies that may improve students’ self-learning and self-efficacy.

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Design of smart assist device for the visually impaired

2024-02-08 , Zahereel Ishwar Abdul Khalib , Nur Hafizah Ghazali , Mohamed Elshaikh Elobaid Said Ahmed , Salimin H.A.M.

Vision impaired individuals suffer from the lack of surrounding information which makes moving around very hard for them. In this work, a smart belt is designed to assist the blind in detecting obstacles and holes in front of them. Upon detection, the smart belt will notify the user by means of a textual audio message. The device utilizes a Raspberry Pie single-board computer as well as two ultrasonic sensors as the main component. Test results indicate that the system manages to provide accurate measurement of the distance to the obstacles with +- 1cm error. The system has been designed to cater gait movement as well as the variability of flat surface. This is important to avoid false positive and false negative alarm to the user. Using the belt is very convenient as compared to the white stick. It is easy to wear on the waist and once activated the device shall auto-calibrate its distance to the ground before obstacle/hole detection mode is activated automatically a few seconds later.

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An Effective Salp Swarm Based MPPT for Photovoltaic Systems under Dynamic and Partial Shading Conditions

2021-01-01 , Jamaludin M.N.I. , Mohammad Faridun Naim Tajuddin , Ahmed J. , Azralmukmin Azmi , Syahrul Ashikin Azmi , Nur Hafizah Ghazali , Babu T.S. , Alhelou H.H.

This study proposes a duty cycle-based direct search method that capitalizes on a bioinspired optimization algorithm known as the salp swarm algorithm (SSA). The goal is to improve the tracking capability of the maximum power point (MPP) controller for optimum power extraction from a photovoltaic system under dynamic environmental conditions. The performance of the proposed SSA is tested under a transition between uniform irradiances and a transition between partial shading (PS) conditions with a focus on convergence speed, fast and accurate tracking, reduce high initial exploration oscillation, and low steady-state oscillation at MPP. Simulation results demonstrate the superiority of the proposed SSA algorithm in terms of tracking performance. The performance of the SSA method is better than the conventional (hill-climbing) and among other popular metaheuristic methods. Further validation of the SSA performance is conducted via experimental studies involving a DC-DC buck-boost converter driven by TMS320F28335 DSP on the Texas Instruments Experimenter Kit platform. Hardware results show that the proposed SSA method aligns with the simulation in terms of fast-tracking, convergence speed, and satisfactory accuracy under PS and dynamic conditions. The proposed SSA method tracks maximum power with high efficiency through its superficial structures and concepts, as well as its easy implementation. Moreover, the SSA maintains a steady-state oscillation at a minimum level to improve the overall energy yield. It thus compensates for the shortcomings of other existing methods.

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An Augmented Reality (AR) marker-based application for smart campus: UniMAP residential college

2020 , Rusnida Romli , Sen, Ng Wen , Nur Hafizah Ghazali , Nik Adilah Hanin Zahri

Augmented Reality nowadays is getting wide usage with all application in human daily life. This paper of research is about the design and development of Augmented Reality (AR) for smart campus urbanization using the student’s residential college. The technique used in this application is marker-based. Then analyze the efficiency of positioning the object on the right place on display screen with the image processing to get the tag from the image and set as the image marker. The image triggered is analyze either it is projected on the image or slightly change from the actual position. The scope of this research is direct and specific as it will help newcomers or visitor to the hostel area to get information and direction easily with this application. There are many area and information inside as the users should know with the guidance of the application. This research is to make an Android-based application with the interfaces of Augmented Reality to demonstrate and testify the proficiency of virtual data and information shown on the device screen and the feasibility of the augmented object plotted and registered at certain places of hostel. Thus, by using this AR technology to enhance user experience in the hostel area with direction and right information instantly. The contribution of this research trying to reach were those first-time visitors when they arrived at the hostel as there is lack of information for them to locate themselves in such a large campus area and assisting them especially in the term of information and directions. Information is easier and capable to receive by the user as they require only a smart phone to operate the advance feature from the AR application. Furthermore, it does not need any of internet connection in order to use the application and can be operated in offline. With the specified and unique images, users are able to view the virtual object in an entertaining AR environment at the same time better presentation of info can also be delivered.

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Mobile Augmented Reality (AR) Marker-based for Indoor Library Navigation

2020-03-20 , Rusnida Romli , Razali A.F. , Nur Hafizah Ghazali , Nik Adilah Hanin Zahri , Siti Zuraidah Ibrahim

This paper presents the development of Augmented Reality (AR) for smart campus urbanization using library as the environment for the demonstration of the AR prototype. The main goal of the AR development is to help users to get information and direction easily using AR based mobile application when walking inside the library. In normal circumstances, users typically walk around and explore the library area before reaching their targeted destinations. Depending on the library size and number of reading corners, exploration and walking in the library can be time consuming. Therefore, an AR technology is introduced in this paper to improve the user experience inside the library in the right direction and information instantly. This application is developed using Vuforia software to set the image marker-based and process the output into Unity3D software, Android Studio for the Main Menu interface and IBM Watson for voice recognition. The final form of the application is successfully generated from the development of Augmented Reality (AR) application for the smart campus by using a library for the demonstration of the AR prototype. A series of application tests are conducted in each corner of the library to evaluate the effectiveness of developed AR.

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