Azizi Harun
Thumbnail Image
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

Filters

27
Reset filters

Settings
Now showing 1 - 10 of 27
  • 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
    Engine Performance Analysis by Studying Heat Transfer in the Valve Seat through Steady-State Thermal Simulation
    ( 2021-12-14)
    Mohamad Aniq Syazwan Mohamed Hassan
    ;
    Shahriman Abu Bakar
    ;
    Zuradzman Mohamad Razlan
    ;
    Nur Saifullah Kamarrudin
    ;
    Wan Khairunizam Wan Ahmad
    ;
    Mohd Sani Mohamad Hashim
    ;
    Azizi Harun
    ;
    Ishak Ibrahim
    ;
    Azizul Aziz I.
    ;
    Zunaidi Ibrahim
    ;
    Mohd Khairul Faizi Abd Rahman
    ;
    Muhammad Faiz Hilmi Rani
    ;
    Anas Abdul Rahman
    ;
    Mohd Afendi Rojan
    ;
    Rishan Murali
    As the engine reached high speed, the exhaust valve temperature increased exponentially due to the exhaust gas produced by the combustion process between the mixture of air and fuel within the combustion chamber of the internal combustion engine. The valve is subjected to thermal loading due to high temperature and pressure within the cylinder, which must withstand a material temperature for sustainable and optimal operation. To avoid this loss, a perfect medium must be prepared to ensure that the heat is extracted smoothly. This can be done when the valve is in contact with the seat and there is a periodic heat transfer contact. Therefore, it is imperative to research the correlation between valve and valve seat to understand the two sections' heat transfer mechanism. In this study, thermal contact analysis was used to identify heat transfer between the valve and the valve seat as both parts are interconnected. This research also has an interest in studying the two surface conduction mechanisms as the exhaust valve closed in steady-state conditions. Thus, this study portrays a significant method, particularly for the determining the distribution of temperature, heat flux, and heat flux direction between the valve and its seat using ANSYS Workbench.
      2
  • 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
    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.
      41  2
  • 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.
      34  2
  • Publication
    Determination of blind spot zone for motorcycles
    ( 2019-12-02)
    Mohd Sani Mohamad Hashim
    ;
    Hamati A.A.A.
    ;
    Mohd Hafzi M.I.
    ;
    Shahriman Abu Bakar
    ;
    Abdul Halim Ismail
    ;
    Muhamad Safwan Muhamad Azmi
    ;
    Azizi Harun
    ;
    Zuradzman Mohamad Razlan
    ;
    Nur Saifullah Kamarrudin
    ;
    Ishak Ibrahim
    ;
    Mohd Khairul Faizi Abd Rahman
    ;
    Mohd Asrul Md Saad
    ;
    Mohd Afendi Rojan
    The problem of the blind spot zone (BSZ) for motorcycles is common, as it causes many accidents that occur between motorcycles and cars, or motorcycles with other vehicles. The problem of BSZ is occurring for many reasons, such as if the motorcyclist wants to change the lane or manoeuvre or turn without realizing the presence of other vehicle which may cause a terrible collision and leads to casualties, either because of darkness, the full dependence on side mirrors that give a limited scope of vision, or due to a malfunction in the front lights of the car that prevented the motorcyclists from recognizing it. However there were limited research on identifation of BSZ for motorcycle, even though most vehicle accidents in Malaysia involved motorcycles. This paper discusses the initial works on the identification of BSZ for motorcyles. Three types of motorcycles were used to determine the BSZ using grid-based technique. From the data collected, the BSZ was identified for the motorcycles.
      2