Now showing 1 - 10 of 35
  • Publication
    Temperature monitoring system using fiber Bragg grating (FBG) approach
    In this paper, a temperature monitoring system is proposed by using fiber Bragg Grating (FBG) approach. This system can be done by using OptiSystem simulation and hardware implementation. FBG was employed as it allows a reflected wavelength of light that shifts in response to variations in temperature and/or strain. Generally, FBG sensors offer ease of installation, higher accuracy, longer stability, smaller size, immunity to electromagnetic interference (EMI) and the ability to measure ultra-high and speed events. The results indicated that wavelength shifting is depended on thermal expansion coefficient of materials, which are 0.55e-6 for default and 24e-6 for aluminium. Aluminum has a better sense rather than the default one in this study. For hardware implementation, it is shown that the power level is increased from one value to another progressively.
  • Publication
    Medical healthcare M2M system using the VLC system
    The RF communication has suffered from the interference and excessive latency issues. It is required a separated setup for transmission and reception of RF waves. To overcome this problem, the VLC system is a chosen technique due to high bandwidth and immunity to interference from electromagnetic sources. In this project, Optisystem Software version 15 has been chosen to study the perfomances of the VLC system in directed LOS. The performance results will be displayed on BER analyser and the simulation that has been done is iterating continuously in order to get the acceptable results. The result indicates that the reading of simulation of 1 user for both bit rate 155Mbps and 622Mbps shows the best result compared to 4 users. Without using any kind of OCDMA system, the number of users will reach the limitations which is not more than 4 users. The number of users influences the performance of the system and the result shows the decrement of BER reading which is lower than 10-9.
  • Publication
    Nitrate (NO3-) prediction in soil analysis using near-infrared (NIR) spectroscopy
    ( 2020-01-08)
    Sabri, Mohd Shafiq Amirul
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    ; ; ; ;
    Laili M.H.
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    Laili A.R.
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    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.
  • Publication
    Prediction model for spectroscopy using python programming
    ( 2021-12)
    A A M Ismail
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    Mohd Shafiq Amirul
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    This paper is motivated by searching for the perfect pattern for the spectroscopy spectra using artificial neural networks (ANN) using python programming coding. The pattern from the spectroscopy is based on the absorption and emission of light and other radiation by materials in relation to the wavelength dependence of these processes. Spectral equipment such as spectrometers, spectral analysers, spectrographs, or spectrophotometers is utilised to determine spectrum values. The problem in this spectroscopy is to identify the sample or analyte, which can be solved by a prediction model for spectroscopy using Python. These problems occur when finding the best algorithm of pre-processing techniques that can predict any model accurately into an understandable format for prediction models. Various types of pre-processing techniques have been used, such as Multiplicative Scatter Correction (MSC), Inverse MSC, Extended MSC (EMSC), Extended Inverse MSC, de-trending, Standard Normal Variate (SNV) and normalisation in order to get a better r2 value. In this project, we find the r2 and the root mean square error (RMSE) to evaluate the prediction values and the actual values. First, choosing pre-processing techniques and then finding the best statistical method for constructing predictive models that produce high accuracy. We used ANN in this project as a prediction model. Based on the results, we managed to achieve our objective, which is that the prediction model has more than 90% of accuracy. Furthermore, the results show that our prediction model has 1.0 accuracy at 100 Epoch with a 0.3 learning rate. Finally, we can conclude that our prediction model can be used to predict the spectroscopy-based data format.
  • Publication
    Thermal properties and mass spectra of heavy mesons in the presence of a Point-Like defect
    ( 2024)
    Etido P. Inyang
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    ; ; ; ;
    N.R. Ali
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    Muhammad Muhammad Asjad
    In this research, the radial Schr¨odinger equation is solved analytically using the Nikiforov-Uvarov method with the Cornell potential. The energy spectrum and the corresponding wave function are obtained in close form. The effect of Topological Defect on the thermal properties and mass spectra of heavy mesons such as charmonium and bottomonium are studied with the obtained energy spectrum. It is found that the presence of the Topological Defect increases the mass spectra and moves the values close to the experimental data. Our results agreed with the experimental data and are seen to be improved when compared with other works.
  • Publication
    Enrichment of wireless data transmission based on visible light communication for triple play service application
    In this paper, the performance of the LiFi-IoT based on VLC for point-to-point (P2P) topology has been investigated. LiFi-IoT offers a possibility to deploy high speed (∼1 Gbps) wireless data for future network access optical wireless communication (UOWC). Result shows that, the LED threshold current of 16 mA corresponds to a voltage of 0.6 V. At the injection current of 30 mA, the LED has an output optical power of 18 mW for data transmission to be carried out under the optical communication environment based on Line of Sight (LoS).
  • Publication
    Comparison between conventional OCDMA and subcarrier multiplexing SAC OCDMA system based on single photodiode detection
    This paper demonstrates the comparison between conventional OCDMA system and subcarrier multiplexing (SCM) SAC-OCDMA system by applying Recursive Combinatorial (RC) code based on single photodiode detection (SPD). SPD is used in the receiver part to reduce the effect of multiple access interference (MAI) which contributes as a dominant noise in incoherent SAC-OCDMA systems. From this analysis, the performance of SCM OCDMA network could be improved by using lower data rates and higher received power. The hybrid SCM OCDMA system shows better performance compare to conventional OCDMA system although the number of users involved is very high. This is because, for hybrid SCM OCDMA system, the number of users can be increased by increasing the number of subcarriers without affect the number of code length and optical codes. Increasing the number of subcarriers will enhance the power consumption by applying hybrid SCM system in OCDMA compared to the conventional OCDMA system. This is because increasing the number of users for hybrid SCM system does not affects the number of code length and the number of optical codes but only increase the number of subcarriers. Thus, hybrid SCM OCDMA system has to increase spectral efficiency and produce better performance compared to conventional of OCDMA system
  • Publication
    Hybrid WDM and Optical-CDMA over Multi-Mode Fiber Transmission System based on Optical Vortex
    ( 2021-03-01)
    Ghazi A.
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    ; ; ; ;
    Ali N.
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    A.dawoodi
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    Fakhrudeen A.M.
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    Fareed A.
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    Sharma T.
    The optical vortex has recently attracted scholars to implement it in optical tweezers, microscopy, optical communications, quantum information processing, optical trapping, and laser machining. Optical vortex beam applied classically that can be transferred to the transverse amplitude of a heralded single-photon, and optical vortex possesses a helical wavefront and carries orbital angular momentum. In this study, Optical vortex is applied in optical-CDMA (optical code-division multiple-access) in conjunction with WDM (wavelength division multiplexing). This mechanism aims to increase the capacity and security in optical communication significantly. The implementation of Laguerre-Gaussian (LG) modes with optical vortex based on one dimension zero cross-correlation (ZCC) code shows that mode coupling reduces effectively. Consequently, a positive increase in channel performance and response. Accordingly, the LG modes based on the 1D-ZCC code are investigated and propagated over multi-mode fiber (MMF) based on an optical vortex, which also substantially reduces channel effects. Consequently, all these attributes combined will result in a hybrid WDM-Optical-CDMA with an optical vortex system over MMF.
  • Publication
    Performance Analysis of Coherent Source SAC OCDMA in Free Space Optical Communication Systems
    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.