Syed Alwee Aljunid Syed Junid
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Syed Alwee Aljunid Syed Junid
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Syed Alwee Aljunid, Syed Junid
Alternative Name
Aljunid, S.
Aljunid, Syed Alwi
Aljunid, Syed A.
Aljunid, S. Alwee
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Scopus Author ID
56000543300

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Now showing 1 - 8 of 8
  • Publication
    Prediction of soil macronutrient (nitrate and phosphorus) using near-infrared (NIR) spectroscopy and machine learning
    ( 2020-01-08)
    Laili A.R.
    ;
    Rosdisham Endut
    ;
    Norshamsuri Ali @ Hasim
    ;
    Laili M.H.
    ;
    Amirul M.S.
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    Mohd Rashidi Che Beson
    ;
    Ismail M.N.M.
    Determination of basic soil macronutrients such as nitrogen (N), phosphorus (P) and potassium (K) that dissolve from organic matter (OM) prior to the plantation of fruit and vegetable corps is one of the important process of soil preparation towards precision farming. In this paper comparative analysis is performed for detection algorithm on OM, (N) and (P) sample using near infrared spectroscopy (NIRS) spectrometer in reflective mode with an effective range of 900nm to 1700nm. In pre-processing we execute data dimension reduction by combining multiple feature selection such as data normalization, permutation feature importance, principle component analysis, fisher linear discriminant and filter-based feature selection. Pre-processing able to reduce 50% data dimension. For prediction model development we combine with multiple classification algorithm such as multiclass decision jungle, decision forest, logistic regression and neural network to come out with highest accuracy of N and P detection. We conclude that near infrared spectroscopy combines with feature selection and multiclass classification able to determine nitrogen and phosphorus.
  • Publication
    Estimation of Harumanis (Mangifera indica L.) Sweetness using Near-Infrared (NIR) Spectroscopy
    ( 2020-03-20)
    Sabri, Mohd Shafiq Amirul
    ;
    Rosdisham Endut
    ;
    Mohd Rashidi Che Beson
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    Norshamsuri Ali @ Hasim
    ;
    Laili M.H.
    ;
    Laili A.R.
    ;
    Ismail M.N.M.
    Harumanis mango quality demanded by consumers is depending on the sweetness level of the fruit. The sweetness is evaluated by brix percentage using refractometer as a representative factor correlated with near-infrared (NIR) spectroscopy spectral absorbance. NIR spectroscopy method of sampling have been tested to overcome the time consuming, complex chemical analysis more importantly invasive sampling methods in order to determine the sugar content in mangoes. Spectral absorbance data from range 941 nm to 1685 nm of mango skin is correlated with Brix reading then tested through five pre-processing techniques. Data calibration and prediction of both data is evaluated using Partial Least Square Regression (PLSR) model. In the final analysis, Unit vector normalization (UVN) technique has achieved as a best pre-processing technique for predicting results, with the coefficient of determination (R2) values of 0.9836 and root mean square error (RMSE) values of 0.3131. Overall, the correlation of NIRS absorbance data and Brix data can be obtained using PLSR model with UVN pre-processing technique. Henceforth, we can conclude that the NIRS method of sampling can be used to identify sugar content in Harumanis mango by using time saving, non-invasive and less laborious method of sampling.
  • Publication
    Adaptive threshold determination for efficient channel sensing in cognitive radio network using mobile sensors
    ( 2017-03-13)
    Mohammad Nayeem Morshed
    ;
    Sabira Khatun
    ;
    Latifah Munirah Kamarudin
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    R Badlishah Ahmad
    ;
    Ammar Zakaria
    ;
    Moslem Fakir
    Spectrum saturation problem is a major issue in wireless communication systems all over the world. Huge number of users is joining each day to the existing fixed band frequency but the bandwidth is not increasing. These requirements demand for efficient and intelligent use of spectrum. To solve this issue, the Cognitive Radio (CR) is the best choice. Spectrum sensing of a wireless heterogeneous network is a fundamental issue to detect the presence of primary users' signals in CR networks. In order to protect primary users (PUs) from harmful interference, the spectrum sensing scheme is required to perform well even in low signal-to-noise ratio (SNR) environments. Meanwhile, the sensing period is usually required to be short enough so that secondary (unlicensed) users (SUs) can fully utilize the available spectrum. CR networks can be designed to manage the radio spectrum more efficiently by utilizing the spectrum holes in primary user's licensed frequency bands. In this paper, we have proposed an adaptive threshold detection method to detect presence of PU signal using free space path loss (FSPL) model in 2.4 GHz WLAN network. The model is designed for mobile sensors embedded in smartphones. The mobile sensors acts as SU while the existing WLAN network (channels) works as PU. The theoretical results show that the desired threshold range detection of mobile sensors mainly depends on the noise floor level of the location in consideration.
      23  1
  • 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.
      36  5
  • Publication
    A new class of two-dimensional (2-D) modified-FCC (M-FCC) OCDMA for cardinality enrichment towards 6G network accessibility
    ( 2024-01-31)
    Dayang H.
    ;
    Mohd Rashidi Che Beson
    ;
    Syed Alwee Aljunid Syed Junid
    In this paper, we introduce a new two-dimensional (2-D) wavelength/time optical code division multiple access (OCDMA) known as 2D Modified-Flexible Cross Correlation (M-FCC) code. The 2-D M-FCC code is developed from the one-dimensional flexible cross correlation code families with flexibility in-phase cross-correlation at any given number of users and weights. The main goal is to reduce noise as well as multiple-access interference (MAI) at the same time to accommodate higher cardinality with minimum noise. The increment of cardinality is to be engaged towards 6G network accessibility. From the numerical results, it indicated good performance whereas the 2-D M-FCC code at bit rate 622 Mbps with at BER of 3.49 ×10-28, can accommodate 200 number of cardinalities enrichment. Moreover, the 2-D M-FCC code shows good SNR curves as gradually decreases as the number of users increases at different bit rate 155 Mbps, 622 Mbps, 1.1 Gbps and 2.5 Gbps, respectively.
      6  27
  • Publication
    Vehicular Ad Hoc Networks Security for Smart Cities Based on 2D ZCC/MD Optical CDMA Code
    ( 2020-01-01)
    Matem R.
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    Junita M.N.
    ;
    Mohd Rashidi Che Beson
    ;
    Saad N.M.
    Due to the increasing numbers of vehicles in the world which results in a rise in traffic density, smart city is seeking to minimize transportation problems such as accidents. To solve this issue, VANET has been developed to improve vehicles’ mobility and provide a safe city. VANET is a type of wireless technology which provides vehicle-to-vehicle (V2V) and vehicle-to-infrastructures (V2I) communication system. Despite the advantages of VANET, it faces a lot of challenges; security and privacy, for instance, are the most critical ones. In this paper, we implement an approach used in Optical CDMA system given its success in optical domain. This technique is based on the 2D ZCC/MD code which is characterized by zero cross-correlation property. The transmission system is based on the VLC system, in which the information will circulate in optic domain using light in free space. The proposed system can provide the security and the privacy due to the 2D ZCC/MD code which assigns each user by a specific unique code.
      3  16
  • Publication
    Nitrate (NO3-) prediction in soil analysis using near-infrared (NIR) spectroscopy
    ( 2020-01-08)
    Sabri, Mohd Shafiq Amirul
    ;
    Rosdisham Endut
    ;
    Mohd Rashidi Che Beson
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    Norshamsuri Ali @ Hasim
    ;
    Laili M.H.
    ;
    Laili A.R.
    ;
    Ismail M.N.M.
    Nutrient composition in soil analysis is investigated by using nitrogen (N) in form of nitrate (NO3-) as a representative factor correlated with NIR spectroscopy spectral absorbance. NIR spectroscopy method of sampling has been tested to overcome time consuming, complex chemical analysis procedure and invasive sampling method in order to identify nitrate content in soil samples. Spectral absorbance data from range 950 nm to 1650 nm correlated with nitrate reading then tested through few pre-processing techniques. Five techniques have been listed as top performer, which are Multiplicative Scatter Correction using Common Offset (MSCCO), Multiplicative Scatter Correction (MSC), Range Normalization (RN), Mean Normalization (MN) and Reduced (R) technique. Data calibration and prediction of both data is evaluated using Partial Least Square Regression (PLSR) model. In the final analysis, R technique has achieved as top performer pre-processing technique for both calibration and prediction results, with the coefficient of determination (R2) values of 0.9991 and root mean square error (RMSE) values of 0.0886 for prediction. Overall, the correlation of NIRS absorbance data and nitrate can be obtained using PLSR model with R pre-processing technique. Henceforth, we can conclude that the NIRS method of sampling can be used to identify nitrate content in soil analysis by using time saving, non-invasive and less laborious method of sampling.
      31  3
  • Publication
    Performance Analysis of Coherent Source SAC OCDMA in Free Space Optical Communication Systems
    ( 2023-06-01)
    Alhassan A.M.
    ;
    Issam E.
    ;
    Syed Alwee Aljunid Syed Junid
    ;
    Mohd Rashidi Che Beson
    ;
    Ammar S.M.
    ;
    Norshamsuri Ali @ Hasim
    ;
    Rosdisham Endut
    In this paper, we investigate the performance of spectral amplitude coding optical code division multiple access (SAC OCDMA) systems under the effect of beat noise and turbulence. Three different multi-laser source configurations are considered in this analysis: shared multi-laser, separate multi-laser, and carefully controlled center frequency separate multi-laser. We demonstrate through Monte Carlo simulation that the gamma–gamma probability density function (pdf) cannot adequately approximate the measured intensity of overlapping lasers and that an empirical pdf is required. Results also show it is possible to achieve error-free transmission at a symmetrical data rate of 10 Gbps for all active users when only beat noise is taken into account by precisely controlling the center frequencies. However, only 30% of the active users can be supported when both beat noise and turbulence are considered.
      1  31