Thennarasan Sabapathy
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Preferred name
Thennarasan Sabapathy
Official Name
Thennarasan, Sabapathy
Alternative Name
Sabapathy, Thennarasan
Sabapathy, Thenna
Sabapathy, T.
Sapabathy, T.
Main Affiliation
Scopus Author ID
35424377200
Researcher ID
AAA-9706-2019

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  • Publication
    Design of Reconfigurable Antenna for RFID System
    ( 2021-07-26)
    Renukka Sivakumar
    ;
    Thennarasan Sabapathy
    ;
    Muzammil Jusoh
    ;
    Soh Ping Jack
    ;
    Mohamed Nasrun Osman
    ;
    Salem Al-Bawri S.
    ;
    Jayaprakasam S.
    ;
    Mohd Najib Mohd Yasin
    ;
    Saluja N.
    This paper proposes a reconfigurable antenna for RFID system which can operate between 860MHz to 960MHz frequency that belongs to ultra-high frequency (UHF) band used in Malaysia with the center frequency of 910MHz. One rectangular slot and two triangle-shaped slots are used in designing this antenna. A good circular polarization obtained from the slotted structure along the diagonal axis in the design. RF pin diodes are used as the switching mechanism of the antenna. However, in this work to proof the concept of switching mechanism, copper pins are used as artificial switches. Parasitic elements are deployed on the right and left side of the driven element to assist the radiation pattern reconfiguration. Overall, the proposed antenna able to steer the beam at approximately at -30 , -16 , and 10 with peak gain of 3.2dB and average gain of 2.5dB. With this result, overall coverage of UHF RFID reader antenna could be improved.
  • Publication
    A novel unsupervised spectral clustering for pure-tone audiograms towards hearing aid filter bank design and initial configurations
    ( 2022-01-01)
    Elkhouly A.
    ;
    Allan Melvin Andrew
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Abdulaziz N.
    ;
    Abdulmalek M.
    ;
    Mohd Najib Mohd Yasin
    ;
    Muzammil Jusoh
    ;
    Thennarasan Sabapathy
    ;
    Siddique S.
    The current practice of adjusting hearing aids (HA) is tiring and time-consuming for both patients and audiologists. Of hearing-impaired people, 40–50% are not satisfied with their HAs. In addition, good designs of HAs are often avoided since the process of fitting them is exhausting. To improve the fitting process, a machine learning (ML) unsupervised approach is proposed to cluster the pure-tone audiograms (PTA). This work applies the spectral clustering (SP) approach to group audiograms according to their similarity in shape. Different SP approaches are tested for best results and these approaches were evaluated by Silhouette, Calinski-Harabasz, and Davies-Bouldin criteria values. Kutools for Excel add-in is used to generate audiograms’ population, annotated using the results from SP, and different criteria values are used to evaluate population clusters. Finally, these clusters are mapped to a standard set of audiograms used in HA characterization. The results indicated that grouping the data in 8 groups or 10 results in ones with high evaluation criteria. The evaluation for population audiograms clusters shows good performance, as it resulted in a Silhouette coefficient >0.5. This work introduces a new concept to classify audiograms using an ML algorithm according to the audiograms’ similarity in shape.
  • Publication
    Elastomeric polydimethylsiloxane polymer on conductive interdigitated electrode for analyzing skin hydration dynamics
    ( 2020-09-01)
    Santheraleka Ramanathan
    ;
    Muzammil Jusoh
    ;
    Thennarasan Sabapathy
    ;
    Mohd Najib Mohd Yasin
    ;
    Subash Chandra Bose Gopinath
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Mohamed Nasrun Osman
    ;
    Wahab Y.A.
    With an approach towards generating a wearable skin hydration detecting system, simple, cheap, and flexible skin hydration sensing strategy was demonstrated here using an interdigitated electrode (IDE) coated with polydimethylsiloxane (PDMS) matrix. Aluminium IDE with a 400 Âµm gap and 250 Âµm electrode sizes were fabricated using a photolithography method. Morphological characterizations were performed using a high power microscope, 3D-profilometer, and scanning electron microscope. The dimensions of electrodes and gaps measured through electron microscopic analysis affirmed the exactness of IDE and the fabrication process. After coated with PDMS polymer, the IDE/PDMS surface was examined under a high power microscope and 3D-profilometer. The optical characterization revealed the polymer was coated on IDE through the color-shade changes and smooth surface observed under an optical microscope and the respective 3D-visualization. IDE/PDMS was also analyzed by an atomic force microscope, revealing the smoothness of the IDE surface. Electrical characterizations were performed using different pH and urea solutions and the sweat to investigate the influence of real-time and artificial sweat on IDE/PDMS. As the device showed appropriate results with real-time sweat and no effect with artificial interferences, it is highly encouraged and recommended for detecting skin hydration and the related illnesses with the point-of-care concept.
      3  29
  • Publication
    A negative index nonagonal csrr metamaterial-based compact flexible planar monopole antenna for ultrawideband applications using viscose-wool felt
    ( 2021-08-02)
    Kabir Hossain
    ;
    Thennarasan Sabapathy
    ;
    Muzammil Jusoh
    ;
    Abdelghany M.A.
    ;
    Soh Ping Jack
    ;
    Mohamed Nasrun Osman
    ;
    Mohd Najib Mohd Yasin
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Al-Bawri S.S.
    In this paper, a compact textile ultrawideband (UWB) planar monopole antenna loaded with a metamaterial unit cell array (MTMUCA) structure with epsilon-negative (ENG) and near-zero refractive index (NZRI) properties is proposed. The proposed MTMUCA was constructed based on a combination of a rectangular-and a nonagonal-shaped unit cell. The size of the antenna was 0.825 λ0 × 0.75 λ0 × 0.075 λ0, whereas each MTMUCA was sized at 0.312λ0 × 0.312λ0, with respect to a free space wavelength of 7.5 GHz. The antenna was fabricated using viscose-wool felt due to its strong metal–polymer adhesion. A naturally available polymer, wool, and a human-made poly-mer, viscose, that was derived from regenerated cellulose fiber were used in the manufacturing of the adopted viscose-wool felt. The MTMUCA exhibits the characteristics of ENG, with a bandwidth (BW) of 11.68 GHz and an NZRI BW of 8.5 GHz. The MTMUCA was incorporated on the planar monopole to behave as a shunt LC resonator, and its working principles were described using an equivalent circuit. The results indicate a 10 dB impedance fractional bandwidth of 142% (from 2.55 to 15 GHz) in simulations, and 138.84% (from 2.63 to 14.57 GHz) in measurements obtained by the textile UWB antenna. A peak realized gain of 4.84 dBi and 4.4 dBi was achieved in simulations and measurements, respectively. A satisfactory agreement between simulations and experiments was achieved, indicating the potential of the proposed negative index metamaterial-based antenna for microwave applications.
      1
  • Publication
    A hybrid modified method of the sine cosine algorithm using latin hypercube sampling with the cuckoo search algorithm for optimization problems
    ( 2020-11-01)
    Siti Julia Rosli
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Khairul Najmy Abdul Rani
    ;
    Yahaya N.Z.
    ;
    R Badlishah Ahmad
    ;
    Ruzelita Ngadiran
    ;
    Abdulmalek M.
    ;
    Muzammil Jusoh
    ;
    Mohd Najib Mohd Yasin
    ;
    Thennarasan Sabapathy
    ;
    Allan Melvin Andrew
    The metaheuristic algorithm is a popular research area for solving various optimization problems. In this study, we proposed two approaches based on the Sine Cosine Algorithm (SCA), namely, modification and hybridization. First, we attempted to solve the constraints of the original SCA by developing a modified SCA (MSCA) version with an improved identification capability of a random population using the Latin Hypercube Sampling (LHS) technique. MSCA serves to guide SCA in obtaining a better local optimum in the exploitation phase with fast convergence based on an optimum value of the solution. Second, hybridization of the MSCA (HMSCA) and the Cuckoo Search Algorithm (CSA) led to the development of the Hybrid Modified Sine Cosine Algorithm Cuckoo Search Algorithm (HMSCACSA) optimizer, which could search better optimal host nest locations in the global domain. Moreover, the HMSCACSA optimizer was validated over six classical test functions, the IEEE CEC 2017, and the IEEE CEC 2014 benchmark functions. The effectiveness of HMSCACSA was also compared with other hybrid metaheuristics such as the Particle Swarm Optimization–Grey Wolf Optimization (PSOGWO), Particle Swarm Optimization–Artificial Bee Colony (PSOABC), and Particle Swarm Optimization–Gravitational Search Algorithm (PSOGSA). In summary, the proposed HMSCACSA converged 63.89% faster and achieved a shorter Central Processing Unit (CPU) duration by a maximum of up to 43.6% compared to the other hybrid counterparts.
      10  46
  • Publication
    Higher Order OAM Mode Generation Using Wearable Antenna for 5G NR Bands
    ( 2023-01-01)
    Noor S.K.
    ;
    Arif Mawardi Ismail
    ;
    Mohd Najib Mohd Yasin
    ;
    Mohamed Nasrun Osman
    ;
    Thennarasan Sabapathy
    ;
    Shakhirul Mat Salleh
    ;
    Soh Ping Jack
    ;
    Rambe A.H.
    ;
    Ramli N.
    This paper presents a flexible and wearable textile array antenna designed to generate Orbital Angular Momentum (OAM) waves with Mode +2 at 3.5 GHz (3.4 to 3.6 GHz) of the sub-6 GHz fifth-generation (5G) New Radio (NR) band. The proposed antenna is based on a uniform circular array of eight microstrip patch antennas on a felt textile substrate. In contrast to previous works involving the use of rigid substrates to generate OAM waves, this work explored the use of flexible substrates to generate OAM waves for the first time. Other than that, the proposed antenna was simulated, analyzed, fabricated, and tested to confirm the generation of OAM Mode +2. With the same design, OAM Mode −2 can be generated readily simply by mirror imaging the feed network. Note that the proposed antenna operated at the desired frequency of 3.5 GHz with an overall bandwidth of 400 MHz in free space. Moreover, mode purity analysis is carried out to verify the generation of OAM Mode +2, and the purity obtained was 41.78% at free space flat condition. Furthermore, the effect of antenna bending on the purity of the generated OAM mode is also investigated. Lastly, the influence of textile properties on OAM modes is examined to assist future researchers in choosing suitable fabrics to design flexible OAM-based antennas. After a comprehensive analysis considering different factors related to wearable applications, this paper demonstrates the feasibility of generating OAM waves using textile antennas. Furthermore, as per the obtained Specific Absorption Rate (SAR), it is found that the proposed antenna is safe to be deployed. The findings of this work have a significant implication for body-centric communications.
      45  6
  • Publication
    Multi-stage feature selection (MSFS) algorithm for UWB-based early breast cancer size prediction
    ( 2020-08-01)
    Vijayasarveswari V.
    ;
    Allan Melvin Andrew
    ;
    Muzammil Jusoh
    ;
    Thennarasan Sabapathy
    ;
    Rafikha Aliana A Raof
    ;
    Mohd Najib Mohd Yasin
    ;
    R Badlishah Ahmad
    ;
    Khatun S.
    ;
    Hasliza A Rahim @ Samsuddin
    Breast cancer is the most common cancer among women and it is one of the main causes of death for women worldwide. To attain an optimum medical treatment for breast cancer, an early breast cancer detection is crucial. This paper proposes a multistage feature selection method that extracts statistically significant features for breast cancer size detection using proposed data normalization techniques. Ultra-wideband (UWB) signals, controlled using microcontroller are transmitted via an antenna from one end of the breast phantom and are received on the other end. These ultra-wideband analogue signals are represented in both time and frequency domain. The preprocessed digital data is passed to the proposed multistage feature selection algorithm. This algorithm has four selection stages. It comprises of data normalization methods, feature extraction, data dimensional reduction and feature fusion. The output data is fused together to form the proposed datasets, namely, 8-HybridFeature, 9-HybridFeature and 10-HybridFeature datasets. The classification performance of these datasets is tested using the Support Vector Machine, Probabilistic Neural Network and Naïve Bayes classifiers for breast cancer size classification. The research findings indicate that the 8-HybridFeature dataset performs better in comparison to the other two datasets. For the 8-HybridFeature dataset, the Naïve Bayes classifier (91.98%) outperformed the Support Vector Machine (90.44%) and Probabilistic Neural Network (80.05%) classifiers in terms of classification accuracy. The finalized method is tested and visualized in the MATLAB based 2D and 3D environment.
      2  39
  • Publication
    Mobile Green E-Waste Management Systems using IoT for Smart Campus
    ( 2021-07-26)
    Khairul Najmy Abdul Rani
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Ong B.T.
    ;
    Muzammil Jusoh
    ;
    Mohd Najib Mohd Yasin
    ;
    Thennarasan Sabapathy
    ;
    Wan Azani Wan Mustafa
    ;
    Mohd Aminudin Jamlos
    ;
    R Badlishah Ahmad
    ;
    Hammood D.A.
    This paper presents the design and development of mobile "green"electronic waste (e-waste) management systems using Internet of Things (IoT) for smart campus. The system uses Raspberry Pi 3 Model B v1.2 microcontroller for monitoring e-waste object detection, e-waste count, and bin percentage level, respectively. TensorFlow Lite application programming interface (API) is used to run Single Shot Multibox Detector (SSD)Lite-MobileNet-v2 model trained on Microsoft Common Objects in Context (MSCOCO) dataset for e-waste object detection in image. All the monitoring data are stored and retrieved in ThingSpeak cloud platform using Hypertext Transfer Protocol (HTTP) and Message Queuing Telemetry Transport (MQTT) protocol over the Internet and displayed via interactive Android-based mobile user interface (UI). Furthermore, automatic e-mail notification will be sent to waste collector for bin collection whenever e-waste bin percentage level is greater than predetermined threshold value of 80% full.
      3  30
  • Publication
    Pattem-Reconfigurable PCB-based Phased Array for WLAN Applications
    ( 2020-08-04)
    Kabir Hossain
    ;
    Thennarasan Sabapathy
    ;
    Muzammil Jusoh
    ;
    Ping Jack Soh
    ;
    Mohamed Nasrun Osman
    ;
    Mohd Najib Mohd Yasin
    ;
    Hafizah Abdul Rahim
    ;
    Hodgkinson C.J.
    ;
    Podilchak S.K.
    A pattern-reconfigurable microstrip patch array antenna with switchable beams for WLAN application is presented. The proposed 1×2 array can steer the beam approximately to-30, 0, and +30 in the H(xz)-plane with the aid of DC biasing circuitry. An external switching circuit was also developed to measure the prototype effectively. The overall size of the proposed antenna prototype is 0.98?0 × 0.51?0 × 0.01?0 at 2.45 GHz, where the beam can be tilted by controlling the RF signal path through the developed microstrip feedline network using p-i-n diodes.
      2  35
  • Publication
    Electrically tunable Left-Handed textile metamaterial for microwave applications
    ( 2021)
    Kabir Hossain
    ;
    Thennarasan Sabapathy
    ;
    Muzammil Jusoh
    ;
    Ping Jack Soh
    ;
    Mohd Haizal Jamaluddin
    ;
    Samir Salem Al-Bawri
    ;
    Mohamed Nasrun Osman
    ;
    R. Badlishah, Ahmad
    ;
    Hasliza A Rahim @ Samsuddin
    ;
    Mohd Najib Mohd Yasin
    ;
    Nitin Saluja
    An electrically tunable, textile-based metamaterial (MTM) is presented in this work. The proposed MTM unit cell consists of a decagonal-shaped split-ring resonator and a slotted ground plane integrated with RF varactor diodes. The characteristics of the proposed MTM were first studied independently using a single unit cell, prior to different array combinations consisting of 1 × 2, 2 × 1, and 2 × 2 unit cells. Experimental validation was conducted for the fabricated 2 × 2 unit cell array format. The proposed tunable MTM array exhibits tunable left-handed characteristics for both simulation and measurement from 2.71 to 5.51 GHz and provides a tunable transmission coefficient of the MTM. Besides the left-handed properties within the frequency of interest (from 1 to 15 GHz), the proposed MTM also exhibits negative permittivity and permeability from 8.54 to 10.82 GHz and from 10.6 to 13.78 GHz, respectively. The proposed tunable MTM could operate in a dynamic mode using a feedback system for different microwave wearable applications.
      4  22