Azizi Harun
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Preferred name
Azizi Harun
Official Name
Azizi, Harun
Alternative Name
Harun, Azizi
Harun, A.
Bin Harun, Azizi
Main Affiliation
Scopus Author ID
15063856600
Researcher ID
V-6892-2019

Research Output

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  • Publication
    Signal propagation analysis for low data rate wireless sensor network applications in sport grounds and on roads
    ( 2012)
    David L. Ndzi
    ;
    M. A. Mohd Arif
    ;
    Ali Yeon Md Shakaff
    ;
    Mohd Noor Ahmad
    ;
    Azizi Harun
    ;
    Latifah Munirah Kamarudin
    ;
    Ammar Zakaria
    ;
    Mohd F. Ramli
    ;
    Mohammad Shahrazel Razalli
    This paper presents results of a study to characterise wire- less point-to-point channel for wireless sensor networks applications in sport hard court arenas, grass fields and on roads. Antenna height and orientation effects on coverage are also studied and results show that for omni-directional patch antenna, node range is reduced by a factor of 2 when the antenna orientation is changed from vertical to horizontal. The maximum range for a wireless node on a hard court sport arena has been determined to be 70m for 0dBm transmission but this reduces to 60m on a road surface and to 50m on a grass field. For horizontal antenna orientation the range on the road is longer than on the sport court which shows that scattered signal components from the rougher road surface combine to extend the communication range. The channels investigated showed that packet error ratio (PER) is dominated by large-scale, rather than small-scale, channel fading with an abrupt transition from low PER to 100% PER. Results also show that large-scale received signal power can be modeled with a 2nd or der log-distance polynomial equation on the sport court and road, but a 1st order model is sufficient for the grassfield. Small-scale signal variations have been found to have a Rice distribution for signal to noise ratio levels greater than 10 dB but the Rice K-factor exhibits significant variations at short distances which can be attributed to the influence of strong ground reflections.
  • Publication
    Effect of roadways plantation on signal propagation analysis in connected autonomous vehicle communication
    ( 2019)
    J S C Turner
    ;
    Shahriman Abu Bakar
    ;
    Azizi Harun
    ;
    Mohd Sani Mohamad Hashim
    ;
    Zuradzman Mohamad Razlan
    ;
    Wan Khairunizam Wan Ahmad
    ;
    Zunaidi Ibrahim
    ;
    Abu Hassan Abdullah
    ;
    M A Fadzilla
    ;
    K A A Kassim
    ;
    M S A Khalid
    ;
    Z Jawi
    ;
    M H M Isa
    ;
    S A Z Murad
    ;
    Rizalafande Che Ismail
    At present, the development of autonomous vehicle has altered the outlook of modern transportation worldwide. The state-of-the-art vehicular communication for transportation system is advancing, especially in vehicle to infrastructure (V2I) communication. An effective communication between vehicle and infrastructure has become a significant part of autonomous transportation criteria. The necessity for high quality of service communication inspire for good planning and preparation in communication process. Per se, this paper proposes vegetation attenuation models for advance planning of communication process between vehicle to infrastructure, defined mainly by plants, trees and vegetation along the roadways in Malaysia. The channel measurement performed in Universiti Malaysia Perlis test-bed having large tall trees and low shrubs along the routes resulted in several interesting results which would shape the planning of CAV communication. It is observed that communication close to low plantation or shrub requires high power consumption as the range is significantly reduced. It is also learned that certain types of plantations allows for different level of signal attenuation depending on the antenna heights. The research also found out that the attenuation profile follows strictly the log normal distribution and as such certain planning could be made to reshape the communication process to cater for this.
  • Publication
    Deployment of wireless sensor network (WSN) in agricultural environment in northen Malaysia
    ( 2014)
    Azizi Harun
    The advent of Wireless Sensor Networks (WSN) has been fuelled mainly by the advancement in miniaturization of electronic devices and the rise of high volume manufacturing that has been the key supporting factor for the advancement economically. Recent food crises happening over various parts of the world triggered the consciousness over food security and food production capability. For the modern food production to be successful, a thorough understanding and awareness of temporal and spatial crops behaviour is super critical. Thus the use of sensor and wireless sensor networks and proper deployment planning to support modern precision farming is the key to optimum coverage establishment in the farmland. This thesis was written based on the following objectives; assessment energy consumption in WSN nodes as a function of data transmission interval and transmission power level setting; configure a system for short to mid-range link measurement for the study in agricultural environment. The thesis also evaluates existing signal path loss models, identifies or develops new path loss models for WSN system in agricultural environment. Additionally, the thesis also design and model a wide area WSN in agricultural environment. To meet the objectives, propagation path loss measurements were conducted in multiple types of agricultural environments which cover assessment in mixed crop plantation, aquaculture ponds, green houses and mono crop plantations. Path loss models were evaluated and or developed and results were used in WSN simulation. Concurrently, WSN nodes energy consumption assessment was carried out and results used in the WSN simulation. Output from these study and measurements are energy consumption assessment in WSN nodes, path loss models and results from WSN simulation in agricultural environment. Measurement results acquired from the studies show that Log-distance model is the best fit model for measurement in mixed crop plantation while 2-ray model is sufficient to describe the propagation in aquaculture environment. Signal variation in aquaculture is influenced by changes in temperature, humidity and thus refractive index of the medium. Studies in mango greenhouse shows that signal fluctuation varies with vegetation density and Non Zero Gradient model can describe the overall signal propagation while Modified Exponential Decay is more appropriate for lower antenna height. Non Zero Gradient model with specific parameters can be used to describe overhead trellis type grape in greenhouse. For mono-crop plantation, Non Zero Gradient is suitable to describe ISM (Industrial, Scientific and Medical) band frequencies while Modified Exponential Decay is more suitable for frequency 800 MHz to 4.2 GHz in rubber plantation. Modified Exponential Decay is best describe the propagation at branch level while Non Zero Gradient at canopy level. For palm plantation, Modified Exponential Decay best describe signal propagation at trunk while Maximum Attenuation is at canopy level. A deployment model simulation was done at the end of the thesis illustrating the potential coverage based on power consumption in various signal behavior in mixed crop plantation.
  • Publication
    Development of Soil Electrical Conductivity (EC) Sensing System in Paddy Field
    ( 2021-03-01)
    Othaman N.N.C.
    ;
    Mohd Nazrin Md Isa
    ;
    Razaidi Hussin
    ;
    Rizalafande Che Ismail
    ;
    Siti Zarina Md Naziri
    ;
    Sohiful Anuar Zainol Murad
    ;
    Azizi Harun
    ;
    Muhammad Imran Ahmad
    The amount of fertilisers affects electrical conductivity (EC), and it is one of the major causes of the paddy yield decrease. The overuse of fertilisers can lead to environmental pollution and contamination. This study designed to develop soil electrical conductivity (EC) sensing system in the paddy field using the smart farming application. In this work, the study conducted in Kampung Ladang, Kuala Perlis, and the soil samples collected from a random location at two different depths from the paddy field. The EC value for the developed system was near the calibration solutions (12880µS and 150000µS) and directly proportional to the temperature. From the laboratory soil results, the EC values of the soils were higher with fertiliser. However, the EC values for 0-10cm soil depth were higher than 10-20cm soil depth. The soil EC is inversely proportional to the depth of soil and directly proportional to the amount of nutrients. It observed that the soil EC is linearly related to the amount of nutrients and temperature. The EC value decreases with the increase of soil depth displays a low amount of salts in the deep soil, while, increases with the increase of temperature indicates high current flow.
  • Publication
    Design of aquaponics water monitoring system using Arduino microcontroller
    ( 2017-09-26)
    Sohiful Anuar Zainol Murad
    ;
    Azizi Harun
    ;
    Shaiful Nizam Mohyar
    ;
    Rohana Sapawi
    ;
    Ten S.Y.
    This paper describes the design of aquaponics water monitoring system using Arduino microcontroller. Arduino Development Environment (IDE) software is used to develop a program for the microcontroller to communicate with multiple sensors and other hardware. The circuit of pH sensor, temperature sensor, water sensor, servo, liquid crystal displays (LCD), peristaltic pump, solar and Global System for Mobile communication (GSM) are constructed and connected to the system. The system powered by a rechargeable battery using solar energy. When the results of pH, temperature and water sensor are out of range, a notification message will be sent to a mobile phone through GSM. If the pH of water is out of range, peristaltic pump is automatic on to maintain back the pH value of water. The water sensor is fixed in the siphon outlet water flow to detect water flow from grow bed to the fish tank. In addition, servo is used to auto feeding the fish for every 12 hours. Meanwhile, the LCD is indicated the pH, temperature, siphon outlet water flow and remaining time for the next feeding cycle. The pH and temperature of water are set in the ranges of 6 to 7 and 25 °C to 30 °C, respectively.
  • Publication
    Design of 5 V DC to 20 V DC switching regulator for power supply module
    ( 2017)
    Nor Afiqah Azmi
    ;
    Sohiful Anuar Zainol Murad
    ;
    Azizi Harun
    ;
    Rizalafande Che Ismail
    ;
    Mohd Nazrin Md Isa
    ;
    M. A. Zulkifeli
    This paper presents the design of 5 V to 20 V DC switching regulator for power supply module. A voltage multiplier which consists of cascaded diode-capacitor combination is used in order to obtain a high voltage power supply. Due to power loss that has occurred in a stray of component arrangement, the proposed design employs a pulse width modulation (PWM) controller circuit with an inclusion of a capacitor, diode, and inductor components. The input supply of 5 V DC to LT1618 controller circuit has produced 20.35 V based from simulation results. Meanwhile, the measurement results of 19.36 V are obtained and the feedback signal is required for the purpose of stabilizing the output. The proposed design can reduce the components as well as the PCB size, thus minimizing the overall cost of making a switching regulator for power supply module. © 2017 Author(s).
  • Publication
    Signal propagation modelling for vehicle-to-infrastructure communication under the influence of metal obstruction
    ( 2021-12)
    Jamie Siregar Cynthia Turner
    ;
    Shahriman Abu Bakar
    ;
    Azizi Harun
    ;
    Mohd Sani Mohamad Hashim
    ;
    Zuradzman Mohamad Razlan
    ;
    D L Ndzi
    ;
    Rizalafande Che Ismail
    ;
    Sohiful Anuar Zainol Murad
    ;
    Mohd Nazrin Md Isa
    ;
    Shaiful Nizam Mohyar
    ;
    Mohammad Fadzli Ramli
    ;
    M K N Zulkifli
    Connected car has become one of emerging technology in the automotive industries today. This development preludes a rise in vehicular communication studies that primarily targets radio channel modelling on vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication mode. Considering vehicular obstruction, vast channel propagation studies have focused more on V2V mode while others consider the typical urban scenarios consisting of high traffic volumes of moving vehicles. Due to challenging propagation mechanisms and high complexity in such areas, radio propagation models applied in simulators assume an obstacle-free environment rather than considering the least effect imposed by metal obstruction on communication signal. Besides, there are limited studies pertaining to metal obstruction that considers several under-explored environments such as actual parking lots, junctions and other road infrastructure support. As such, this paper demonstrates signal attenuation analysis caused by the presence of metal objects in low density over obstacle-free environment on actual parking lot via V2I mode. Two scenarios such as LOS and NLOS conditions consisting of obstacle-free, cars and buses as static metal objects are evaluated. The aim of this research is to characterize signal strength caused by metal blockage on radio wave propagation predicated on the presence of vehicles as a subject of obstruction in comparison to obstacle-free vehicular environment. The validity of data is shown through received signal strength indicator (RSSI) and approximation analysis (RMSE) to demonstrate the efficiency of obtained measurements. The results demonstrated that Log-normal shadowing model yields the best fit to low-density metal obstruction scenario with smallest RMSE of 4.78 under bus obstruction whereas 5.72 under car obstruction.
  • Publication
    Integration of asset tracking system through trilateration method as detection mechanism
    ( 2019)
    M A Fadzilla
    ;
    Shahriman Abu Bakar
    ;
    Azizi Harun
    ;
    Mohd Sani Mohamad Hashim
    ;
    Zuradzman Mohamad Razlan
    ;
    Wan Khairunizam Wan Ahmad
    ;
    Z. Ibrahim
    ;
    Abu Hassan Abdullah
    ;
    J.S.C Turner
    ;
    K.A.A Kassim
    ;
    M.S.A Khalid
    ;
    Z. Jawi
    ;
    M.H.M Isa
    ;
    Rizalafande Che Ismail
    Demands for localization system has been growing rapidly in the last several years both for an outdoor and indoor area. In conjunction with this, the capability and reliability of this system to precisely locate and track objects of interest for the indoor area has catered researchers and study on how to do so. One of the major ideas on making it more advance is by incorporating the use of wireless devices into the system. There are numbers of issues that could interrupt the efficiency and success of the system. One of the main problems is the signal loss mainly caused by the attenuation of the signal as they propagate through from the transmitter to the receiver. These attenuations are mostly due to the surface types the signal are traveling on and the objects that are in the Line of Sight in between the transmitter and receiver. In order to ensure the most reliable and efficient wireless connection between transmitter and receiver, a propagation study on the signal is needed for us to analyze and find the best way to trade off the signal attenuation based on the environment surrounding the system. By doing so, a thorough system that has models that can work efficiently even if we are to consider the attenuation factors. The system consists of nodes installed inside the research institute that acts as both transmitter and receivers. The transmitter and receiver will then process the signal that will then determine their location. The receiver is connected to the laptop in order to get a real-time reading so that we will be able to locate the transmitter. A networked of nodes are installed inside the research institute for experiment and the layout of the research is conferred for future references. Data from the experiment are then analyzed and a model for the signal propagation alongside the research institute is created. This model will be able to apprehend the signal attenuation despite the surrounding environment such as furniture and walls. A completed asset tracking system with models of signal attenuation will be built in the future for a more efficient signal transmission.
  • Publication
    Low noise figure 2.4 GHz down conversion CMOS mixer for wireless sensor network application
    ( 2017-01-06)
    Sohiful Anuar Zainol Murad
    ;
    Shaiful Nizam Mohyar
    ;
    Azizi Harun
    ;
    Mohd Najib Mohd Yasin
    ;
    Izatul Syafina Ishak
    ;
    Rohana Sapawi
    This work proposed a low noise figure 2.4 GHz down-conversion CMOS mixer for wireless sensor network (WSN) application using 0.13-μm Silterra technology. The proposed down-conversion mixer converts a high radio frequency (RF) signal from 2.4 GHz to an intermediate frequency (IF) of 100 MHz through the use of a local oscillator signal (LO) of 2.3 GHz. The proposed mixer employs a double balance Gilbert-cell topology with integrated input matching at the input stage and a low pass filter at the IF stage. The simulation results indicate that the proposed mixer obtains lower noise figure (NF) of 5.21 dB with an input third-order intercept point (IIP3) of 0 dB. Furthermore, the conversion gain (CG) of 8.6 dB is achieved with the power consumption of 1.57 mW at 1.8 V supply voltage.