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
    Electrical conductivity (EC) sensing system for paddy plant using the internet of things (IoT) connectivity
    ( 2020-01-08)
    Othaman N.N.C.
    ;
    Mohd Nazrin Md Isa
    ;
    Sohiful Anuar Zainol Murad
    ;
    Azizi Harun
    ;
    Shaiful Nizam Mohyar
    This paper presents the design and development of an IoT-based electrical conductivity system for measuring paddy soil nutrients. Relationship between electrical conductivity (EC) and the influence of soil temperature in precision farming will be discussed. In this work, the EC algorithm was modelled and verified using MATLAB and realized on Node MCU (ESP8266) microcontroller. Results showed that the measured data from the developed system is closed to the calibration solution conductivity that is 1.413mS/cm and 12.88mS/cm. It is also noted that the recorded electrical conductivity value increases with temperature.
  • Publication
    Modelling on Impact of Building Obstruction for V2I Communication Link in Micro Cellular Environment
    ( 2021-03-01)
    Turner J.S.C.
    ;
    Shahriman Abu Bakar
    ;
    Azizi Harun
    ;
    Sohiful Anuar Zainol Murad
    ;
    Isa M.N.
    ;
    Ismail R.C.
    ;
    Ndzi D.L.
    ;
    Hashim M.S.M.
    ;
    Zuradzman Mohamad Razlan
    ;
    Wan Khairunizam Wan Ahmad
    ;
    Ramli M.F.
    In vehicular communication, signal transmission in vehicle-to-infrastructure (V2I) mode typically takes place on highways, urban, suburban and rural environments. The presence of buildings in these environments poses a challenge to model path loss (PL) due to multiple propagation mechanisms such as diffractions and reflections. However, very little attention has been made to address building effects on the performance of V2I communication links in microcell environment. This paper investigates signal propagation characteristics caused by the impact of building under micro-cellular environment whereby the base station or road-side-unit (RSU) is usually located under the rooftop of building to allow communication between RSU and mobile station or on-board-unit (OBU) on the road. The goal of this paper is to validate and discuss available path loss models based on effect of building obstruction towards RSU-OBU links specifically in residential housing area. The channel measurements are conducted based on static line-of-sight (LOS) settings of a real-world environment at 2.4 GHz frequency band using IEEE 802.15.4 XBee S2C compliant device to measure its receive power. The results are demonstrated based on received signal strength indicator (RSSI) and root mean square error (RMSE). The attenuation profile is validated and compared with suitable path loss models to evaluate best fit and most compatible model based on our measurements data and environment. The analysis shows that several V2I path loss models and V2V channel models are applicable to be used as a reference to model in LOS microcell environment with building obstruction. The finding shows that PL Urban yields the best fit V2I path loss model in terms of RMSE when compared to our measurement campaign at 2.4 GHz.
      2
  • Publication
    Modeling on impact of metal object obstruction in urban environment for internet of things application in vehicular communication
    ( 2020-01-08)
    Turner J.S.C.
    ;
    Azizi Harun
    ;
    Mohd Najib Mohd Yasin
    ;
    Norshamsuri Ali @ Hasim
    ;
    Shahriman Abu Bakar
    ;
    Fadzilla M.A.
    ;
    Sohiful Anuar Zainol Murad
    ;
    Nor Azura Malini Ahmad Hambali
    ;
    Razlan Z.M.
    ;
    Mohd Sani Mohamad Hashim
    ;
    Wan Khairunizam Wan Ahmad
    ;
    Phoon C.Y.
    Objects such as vehicles are considered one of challenging obstruction on the road and very little attention has been made to address its significance on the wireless signal. As such, this paper validates the impact of vehicle obstruction on signal propagation using received signal strength indicator (RSSI) based on the wireless channel measurements of realistic environmental obstruction at 2.4 GHz frequency band. Low mobility IEEE 802.15.4 XBee S2C compliant device which is designed to collect received signal power was used and these devices were deployed at area congested with cars. The channel measurements were conducted on LOS car parking area with two scenarios; single-sided and double-sided vehicle obstruction which mimics the obstruction of metal objects. The effect of existing vehicle on the signal propagation is demonstrated based on RSSI and RMSE. The attenuation profile of vehicular obstruction on wireless signal is modeled and compared with large-scale propagation models. Results show that metal object significantly reduce transmission range and signal power. The findings may incite for future implementation of cooperative deployment program and internet of things (IoT) applications in vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) communication.
      1  31
  • 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.
      5  22
  • 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.
      2  29
  • Publication
    Speed and Area Efficient FXP Adders and Multipliers: A Comparative Analysis for LNS System
    ( 2020-12-18)
    Basir M.S.S.M.
    ;
    Rizalafande Che Ismail
    ;
    Siti Zarina Md Naziri
    ;
    Mohd Nazrin Md Isa
    ;
    Sohiful Anuar Zainol Murad
    ;
    Azizi Harun
    In this paper, a variety of adder and multiplier are compared to be implemented in a new logarithmic number system (LNS). Both adder and multiplier are designed with a generic very high-speed integrated circuit hardware description language (Verilog) program. This makes it possible to achieve the optimum performance in latency and area of 0.18µm CMOS technologies LNS chip. Consequently, the optimal configurations vary with speed and area of the schemes and in some cases can be compact area, O(n), fast in latency O(log2 n) or optimized. The program was scripted based on fixed-point (FXP) adders and multipliers that yet will be implemented in LNS system. The functionality of the scheme was tested before synthesized. Outcomes show that Ladner Fisher (LF) adder and modified Baugh Wooley multiplier contribute to fast in latency and consume minimal area.
      4  24
  • Publication
    Analog & RF circuits: design & implementation
    ( 2019)
    Sohiful Anuar Zainol Murad
    ;
    Jamilah Karim
    ;
    Noor'ain Kamsani
    ;
    Azizi Harun
    This book entitled ANALOG AND RF CIRCUITS Design and Implementation intentionally covers both analog and radio frequency circuits design and optimization approaches, which is the key feature that distinguishes it from other existing books. It focuses on the theoretical aspects of various designs and simulation and measurement for analog and RF integrated circuits and systems. The book also highlights the unique design issues, which facilitates the reader to understand more advanced research at a good pace. Furthermore, each chapter and subject’s area begins with basic principles and fundamentals and goes into further detail with selected design examples with in-depth discussions and up-to-date references. Read this book to learn more about the design techniques for realizing analog and RF circuits. This book is a comprehensive reference and well-founded material for students as well as electronics engineers and researchers in academia and industry working in the areas of circuits and systems design.
      1  411
  • 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).
      31  1
  • Publication
    Design and development of stingless beehive air pollutant monitoring system
    ( 2021-12)
    Mohammad Fadzli Ramli
    ;
    Azizi Harun
    ;
    Rizalafande Che Ismail
    ;
    Ndzi, David Lorater
    ;
    Turner, Jamie Siregar Cynthia
    ;
    Rohani S Mohamed Farook
    ;
    Mohd Nazrin Md Isa
    ;
    Sohiful Anuar Zainol Murad
    Currently, the presence and levels of air pollution in most stingless bee farms are not measured periodically nor there are proper monitoring levels that can be attributed to hive productivity. Long-term measurement and monitoring of air pollution for hive productivity and honey yield have not been performed. Therefore, this research proposes long-term and real-time air pollution measurement and monitoring techniques that are important for correlation analysis and parameter modeling. By using air pollution detection sensors through a wireless sensor network topology in stingless bee farms, details of pollutant presence and levels will be available in real-time over a long period of time for hive productivity correlation analysis. With such deployment using IoT -based systems, data can be easily accessed from anywhere thus ensuring data continuity. This paper describes a preliminary study on the design, development, and testing of real-time air pollution measurement and monitoring systems capable of determining the health status of stingless bee nests in mixed livestock crop farms. The goal of this research is to help beekeepers/users maintain control and be able to take quick action on the hive from the information obtained.
      2  51
  • 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.
      1  38