Ammar Zakaria
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Preferred name
Ammar Zakaria
Official Name
Ammar, Zakaria
Alternative Name
Zakaria, Ammar
Zakaria, A.
Main Affiliation
Scopus Author ID
36560557700
Researcher ID
D-2902-2015

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  • Publication
    Rf-based moisture content determination in rice using machine learning techniques
    ( 2021-03-01)
    Azmi N.
    ;
    Latifah Munirah Kamarudin
    ;
    Ammar Zakaria
    ;
    Ndzi D.L.
    ;
    Mohd Hafiz Fazalul Rahiman
    ;
    Syed Muhammad Mamduh Syed Zakaria
    ;
    Latifah Mohamed
    Seasonal crops require reliable storage conditions to protect the yield once harvested. For long term storage, controlling the moisture content level in grains is challenging because existing moisture measuring techniques are time-consuming and laborious as measurements are carried out manually. The measurements are carried out using a sample and moisture may be unevenly distributed inside the silo/bin. Numerous studies have been conducted to measure the moisture content in grains utilising dielectric properties. To the best of authors’ knowledge, the utilisation of low-cost wireless technology operating in the 2.4 GHz and 915 MHz ISM bands such as Wireless Sensor Network (WSN) and Radio Frequency Identification (RFID) have not been widely investigated. This study focuses on the characterisation of 2.4 GHz Radio Frequency (RF) transceivers using ZigBee Standard and 868 to 915 MHz UHF RFID transceiver for moisture content classification and prediction using Artificial Neural Network (ANN) models. The Received Signal Strength Indicator (RSSI) from the wireless transceivers is used for moisture content prediction in rice. Four samples (2 kg of rice each) were conditioned to 10%, 15%, 20%, and 25% moisture contents. The RSSI from both systems were obtained and processed. The processed data is used as input to different ANNs models such as Support Vector Machine (SVM), K-Nearest Neighbour (KNN), Random Forest, and Multi-layer Perceptron (MLP). The results show that the Random Forest method with one input feature (RSSI_WSN) provides the highest accuracy of 87% compared to the other four models. All models show more than 98% accuracy when two input features (RSSI_WSN and RSSI_TAG2) are used. Hence, Random Forest is a reliable model that can be used to predict the moisture content level in rice as it gives a high accuracy even when only one input feature is used.
  • 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
    Rice Grain Moisture Sensing Based on UHF RFID Tag
    ( 2022-06-24)
    Radzi A.S.M.
    ;
    Latifah Munirah Kamarudin
    ;
    Latifah Mohamed
    ;
    Ammar Zakaria
    ;
    Mohd Hafiz Fazalul Rahiman
    ;
    Syed Muhammad Mamduh Syed Zakaria
    ;
    Ndzi D.L.
    One of the critical steps in the post-production of paddy rice is to be stored in conditions that need to be controlled, especially the moisture content (MC) of the grains. The ability to determine and control moisture is a very important aspect of maintaining grain quality. This study aims to detect the MC of rice grain using UHF RFID technology. In this paper, three experiments have been carried out to detect the MC of rice in full rice grain-filled containers involving two conditions: with metal and without metal containers. The samples used consist of four 2 kg bags with MC levels of 11.875%, 16%, 20%, and 24%. The Received Signal Strength Indicator (RSSI) values were measured using a UHF handheld reader with two RFID tags to predict the MC. The results show an increasing RSSI pattern as the MC increases.
  • Publication
    Measurement of rice moisture content based on quantitative analysis from radio tomography images
    ( 2024-05-01)
    Nurul Amira Mohd Ramli
    ;
    Mohd Hafiz Fazalul Rahiman
    ;
    Ruslinda A. Rahim
    ;
    Latifah Munirah Kamarudin
    ;
    Latifah Mohamed
    ;
    Moqbel Abdullah M.S.
    ;
    Ammar Zakaria
    Inefficient storage of paddy and rice grains can lead to grain deterioration, resulting in post-harvest losses ranging from 10% to 30%. The quality of grains cannot be improved throughout the storage period. Therefore, following the mechanisation of agricultural industries, air dryers have been developed to control the crops’ moisture level by blowing ambient or heated air into the silo to improve the aeration and allow the grains to be preserved with minimal loss of quality until the appropriate time for managing and marketing processes. However, the conventional sampling method used to measure the moisture level is inefficient because it is very localised and only represents part of the moisture distribution inside the bulk grains. Additionally, incorporating advanced technologies can be a significant cost limitation for small-scale industries. Thus, to address the issue, this research study developed a radio tomographic imaging (RTI) system in a silo-scale prototype using 20 sensor nodes operating at 2.4 GHz to localise and monitor the moisture level constructively. The RTI system reconstructs the cross-sectional images across the rice silo by measuring radio frequency attenuation, in terms of received signal strength (RSS) quality, caused by the rice moisture phantoms within the wireless sensor network (WSN) area. A total of five phantoms’ profiles having a percentage of moisture content (MC)of 15%, 20% and 25% were reconstructed using four image reconstruction algorithms,Linear Back Projection (LBP), Filtered Back Projection (FBP), Newton’s One-step ErrorReconstruction (NOSER) and Tikhonov Regularisation. Then, an image quality assessment,Mean Structural Similarity Index (MSSIM), was utilised to evaluate the performance of thereconstructed images. Lastly, a numerical method based on the first-order linear regressionmodel was introduced as a preliminary approach toward the method’s establishment. In summary, the experimental results demonstrated average image quality scores for all MClevels (15%, 20% and 25%), where the range scores are 0.2776 – 0.4755. Based on thenumerical analysis, the results support the possibility of engaging the proposed techniqueto monitor the moisture level inside a rice silo with the highest and lowest correlationcoefficients of 0.7218 and 0.5442, respectively.
  • Publication
    Design and deployment of LoRaWAN smart streetlight for smart city
    ( 2024-02-08)
    Zakaria S.M.M.S.
    ;
    Ammar Zakaria
    ;
    Latifah Munirah Kamarudin
    ;
    Visvanathan R.
    ;
    Rahim Y.A.
    ;
    Kamarudin K.
    ;
    Azmi N.
    ;
    Mohammad N.S.
    Streetlights are one of the major contributors of a city's energy usage, creating a large carbon footprint especially for highly populated areas. Current streetlights are turned on and off based on fixed schedule or by light sensors. Previous works have suggested the dimming of streetlights during zero traffic conditions to reduce energy consumption. This requires a reliable and economical communication backbone to ensure minimal service disruption. This work presents the design and performance evaluation of LoRa-based smart streetlight controllers in an urban environment. The deployment was designed to provide stress test, simulate communication connectivity, maintenance routine, firmware test and environmental conditions. The setup may also be used for staff training purposes and demonstration. The results of this work may be used achieve the effective control method for power saving, system stability, robustness and long-term performance. The deployed system includes test controllers, nodes, application server, database, gateway server and visualization dashboard. The system design demonstrated low packet error rates of approximately 1% and command response time of less than 3s in real world conditions.
  • Publication
    A new method of rice moisture content determination using voxel weighting-based from radio tomography images
    ( 2021-06-01)
    Ramli N.A.M.
    ;
    Mohd Hafiz Fazalul Rahiman
    ;
    Latifah Munirah Kamarudin
    ;
    Latifah Mohamed
    ;
    Ammar Zakaria
    ;
    Anita Ahmad
    ;
    Rahim R.A.
    This manuscript presents a new method to monitor and localize the moisture distribution in a rice silo based on tomography images. Because the rice grain is naturally hygroscopic, the stored grains’ quality depends on their level of moisture content. Higher moisture content leads to fibre degradation, making the grains too frail and possibly milled. If the moisture is too low, the grains become brittle and are susceptible to higher breakage. At present, the single-point measurement method is unreliable because the moisture build-up inside the silo might be distributed unevenly. In addition, this method mostly applies gravimetric analysis, which is destructive. Thus, we proposed a radio tomographic imaging (RTI) system to address these problems. Four simulated phantom profiles at different percentages of moisture content were reconstructed using Newton’s One-Step Error Reconstruction and Tikhonov Regularization algorithms. This simulation study utilized the relationship between the maximum voxel weighting of the reconstructed RTI image and the percentage of moisture content. The outcomes demonstrated promising results, in which the weighting voxel linearly increased with the percentage of moisture content, with a correlation coefficient higher than 0.95 was obtained. Therefore, the results support the possibility of using the RTI approach for monitoring and localizing the moisture distribution inside the rice silo.
  • Publication
    Study on the effect of atmospheric plasma processing using gas mixture on 3C-SiC
    ( 2017-03-30)
    Zulaika Abdullah
    ;
    Siti Khadijah Za'aba
    ;
    Nashrul Fazli Mohd Nasir
    ;
    Mohammad Taufiq Mustaffa
    ;
    Mayvinne Arcena
    ;
    Ammar Zakaria
    Atmospheric plasma processing are widely used for improving surfaces properties. Cubic silicon carbide (3C-SiC) is one of the material used as biosensor for their biocompatibility properties. In this work, we present the results of atmospheric plasma processing treatments using gas mixture on 3C-SiC surface. The 3C-SiC samples were treated at different duration and flow rate. Helium/Nitrogen and Argon/Nitrogen gas mixtures were used as plasma treatments and its effect on the surface was investigated. A significant increment of surface wettability were observed after plasma exposition. Investigation by surface morphological measurements was performed by using Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). Contact angle measurement results showed a decreased in contact angle with increasing of treatment time and flow rate, and Argon/Nitrogen mixture promote more wettability compared to Helium/Nitrogen mixture.
  • Publication
    Microplasma effect on skin scaffold for melanoma cancer treatment
    ( 2017-03-30)
    Zulaika Abdullah
    ;
    Siti Khadijah Za'aba
    ;
    Mohammad Taufiq Mustaffa
    ;
    Che Wan Sharifah Robiah Mohamad
    ;
    Ammar Zakaria
    An atmospheric plasma system using Helium gas was developed. The effect of helium plasma treatment on skin scaffold surface was studied by scanning electron microscopy (SEM). The changes of skin scaffold surfaces before and after helium plasma treatment was recorded. The surface of skin scaffold changed with the prolonged of helium plasma treatment time. The depth of helium plasma penetration was studied using methylene blue dye staining method. The methylene blue will detect the presence or absence of an oxygen that was induced from plasma excitation. The presence of the oxygen indicated on the depth of helium plasma penetration. Results showed plasma are able to penetrate 4mm of skin scaffold after 1200 seconds of exposure.
  • Publication
    A Bio-Inspired herbal tea flavour assessment technique
    ( 2014)
    Nur Zatul 'Iffah Zakaria
    ;
    Masnan, Maz Jamilah
    ;
    Ammar Zakaria
    ;
    Ali Yeon Md Shakaff
    Herbal-based products are becoming a widespread production trend among manufacturers for the domestic and international markets. As the production increases to meet the market demand, it is very crucial for the manufacturer to ensure that their products have met specific criteria and fulfil the intended quality determined by the quality controller. One famous herbal-based product is herbal tea. This paper investigates bio-inspired flavour assessments in a data fusion framework involving an e-nose and e-tongue. The objectives are to attain good classification of different types and brands of herbal tea, classification of different flavour masking effects and finally classification of different concentrations of herbal tea. Two data fusion levels were employed in this research, low level data fusion and intermediate level data fusion. Four classification approaches; LDA, SVM, KNN and PNN were examined in search of the best classifier to achieve the research objectives. In order to evaluate the classifiers' performance, an error estimator based on k-fold cross validation and leave-one-out were applied. Classification based on GC-MS TIC data was also included as a comparison to the classification performance using fusion approaches. Generally, KNN outperformed the other classification techniques for the three flavour assessments in the low level data fusion and intermediate level data fusion. However, the classification results based on GC-MS TIC data are varied.
  • Publication
    Enhanced experimental investigation of threshold determination for efficient channel detection in 2.4 GHz WLAN cognitive radio networks
    ( 2017-09-01)
    Mohammad Nayeem Morshed
    ;
    Sabira Khatun
    ;
    Latifah Munirah Kamarudin
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    R Badlishah Ahmad
    ;
    Ammar Zakaria
    ;
    Md. Moslemuddin Fakir
    This paper presents an experimental investigation of threshold determination for efficient channel detection in wireless LAN (WLAN) based cognitive radio (CR) networks. The spectrum saturation problem is a critical issue in wireless communication systems worldwide due to on growing user demands day by day with many new applications to the limited frequency spectrum. Hence, present demand is an efficient and intelligent spectrum management and allocation system. In this paper, we proposed an adaptive threshold determination technique based on free space path loss (FSPL) model to detect the presence or absence of PUs. The model is designed especially for Android based smartphones and tablets. The smartphones act as secondary users (SUs) and existing 2.4 GHz WLAN channels as PUs. The network is prepared in a usual noisy lab/outdoor environment and tested for the robustness of the proposed model. Results show the desired range of usable threshold and the channel detection performance depends on the noise floor level of the surrounding environment.