Publications 2019

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https://hdl.handle.net/20.500.14170/3709

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Browsing Publications 2019 by Title

  • Publication
    132kV oil impregnated paper bushing transformer-design by CAD, analysed by FEM
    ( 2019-12-01)
    Rahman N.A.
    ;
    Isa M.
    ;
    Rohani M.N.K.H.
    ;
    Hamid H.A.
    ;
    Al Bakri Abdullah M.M.
    The Electric Field and Voltage Distribution (EFVD) are an important parameter for assessing high voltage bushing transformer performance. However, conducting laboratories experiment is dangerous, difficult and expensive due to several aspects. Therefore, Finite Element Method (FEM) software is the best option used as a tool for the assessment of bushing transformer's performance in terms of EFVD. But, before an assessment of analysis could be carried out, an accurate model of bushing transformer must first to be designed. In this research, Computer Aided Design (CAD) software has been employed to design the 145kV bushing transformer based on actual dimension. Upon completion, the design has been exported to FEM software for further analysis. In FEM software, measurement and analysis of electric field and voltage distribution (EFVD) have been carried out. The measurements are performed at various locations of bushing transformer such as of the porcelain surface (both air and oil side), along with aluminum foils, and at oil-impregnated paper (OIP). The results obtained have been compared with other researchers and it is found very satisfactory.
  • Publication
    2.45 GHZ wearable rectenna array design for microwave energy harvesting
    ( 2019-05-01)
    Shawalil S.
    ;
    Abdul Rani K.N.
    ;
    Rahim H.A.
    This paper presents a design of a wearable textile microstrip patch rectifying antenna (rectenna) array operating for Wireless Body Area Network (WBAN) at the center frequency, f c of 2.45 GHz. Precisely, jeans or denim with the relative permittivity, = 1.70 and thickness of 1.00 mm is chosen as a substrate attached to SheildIt Super as a conductive material with the thickness, h of 0.17 mm and conductivity of 6.67 10 5 S/m, respectively. In the first stage, a microstrip patch antenna array layout with the inset fed technique is designed and simulated by using the Keysight Advanced Design System (ADS) software. In the second stage, a wearable textile microstrip patch antenna array is fabricated, integrated, and hidden inside the jeans fabric. In the third stage, the rectifier circuit layout on the Flame Retardant-4 (FR-4) Printed Circuit Board (PCB) with the dielectric constant, = 4.7, thickness, h = 1.6 mm, and loss tangent, δ = 0.018 that can generate Radio Frequency-Direct Current (RF-DC) conversion is designed and simulated using the ADS software Each simulation result and fabrication measurement shows that the designed antenna array characteristics are suitable for an Industrial, Scientific, and Medical radio (ISM) band by having the reflection coefficient, S 11 less than-10 decibel (dB) at the respective resonant frequency, f r . Moreover, through simulation, the output DC voltage for the bridge rectifier circuit is from 132 mV to 5.01 V with the corresponding Power Conversion Efficiency (PCE) between 3.48% and 50.20% whereas for the voltage doubler rectifier, the output DC voltage is from 417 mV to 2.91 V with the corresponding PCE between 34.78% and 53.56%, respectively.
  • Publication
    2.4GHz RF based active RFID localization in industrial environment
    ( 2019-07-01)
    Wye K.F.P.
    ;
    Kanagaraj E.
    ;
    Syed Zakaria S.M.M.
    ;
    Kamarudin L.M.
    ;
    Zakaria A.
    ;
    Ahmad N.B.
    This paper documents the implementation of a zone-based localization in an industrial environment based on active RFID system by observing the RSSI values. The active RFID system uses signal strength information to classify which zone the RFID tags are located in. The zoning classification uses Rules-based algorithm to determine the RFID tag allocated zone. The experiment testbed is divided into 4 zones and the number of readers is placed based on the activity coverage for the zone. The active RFID reader characteristics was also studied to determine its range and coverage in the industrial environment. The reader was found to cover 40 m × 70 m read range in the current setup. The Rules-based zone localization is verified with the zone profiling throughout the movement around the testbed.
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  • Publication
    5V to 6kV DC-DC converter using switching regulator with cockcroft- walton voltage multiplier for high voltage power supply module
    ( 2019-01-01)
    Azmi N.
    ;
    Murad S.
    ;
    Harun A.
    ;
    Ismail R.
    Background: This paper describes the design of 5 V to 6 kV DC-DC converter by using a switching regulator with Cockroft-Walton (C-W) voltage multiplier for a high voltage power supply module. Methods: The proposed design consists of Pulse Width Modulation (PWM) controller circuit, voltage multiplier, and feedback signal. A single unit of 5 V input triggers LT1618 controller circuit to generate 20 V which then produces 300 V from LT8331 output that is connected to diode-capacitor multiplier circuit to achieve final 6 kV. A negative feedback signal is required to stabilize an output voltage. With the implementation of C-W voltage multiplier technique, the output is boosted up as required from the input signal voltage 5 V DC. Results: The LTspice simulation results indicate that the proposed DC converter can generate 6.20 kV. Line regulation of 17% and the load regulation of 14% are obtained based on the proposed design. Conclusion: The proposed design is suitable for high voltage power supply module.
  • Publication
    A 28 GHz 0.18-μm CMOS cascade power amplifier with reverse body bias technique
    ( 2019-08-01)
    Ahmad Fariz Hasan
    ;
    Sohiful Anuar Zainol Murad
    ;
    Faizah Abu Bakar
    A 28 GHz power amplifier (PA) using CMOS 0.18 μm Silterra process technology is reported. The cascade configuration has been adopted to obtain high Power Added Efficiency (PAE). To achieve low power consumption, the input stage adopts reverse body bias technique. The simulation results show that the proposed PA consumes 32.03mW and power gain (S21) of 9.51 dB is achieved at 28 GHz. The PA achieves saturated power (Psat) of 11.10 dBm and maximum PAE of 16.55% with output 1-dB compression point (OP1dB) 8.44 dBm. These results demonstrate the proposed power amplifier architecture is suitable for 5G applications.
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  • Publication
    A Bidirectional Two-Switch Flyback Converter with Cross-Coupled LCD Snubbers for Minimizing Circulating Current
    ( 2019-08-01)
    Mukhtar N.M.
    ;
    Lu D.D.C.
    This paper proposes a novel isolated bidirectional two-switch flyback converter with two integrated non-dissipative inductor-capacitor-diode (LCD) snubbers. In the proposed topology, the main flyback transformer and the LCD snubbers are cross coupled to minimize circulating current that would occur in the non-cross-coupled case, in addition to recycle leakage energy and protect the power transistors. The same current circulation issue also occurs in the bidirectional flyback converter with conventional resistor-capacitor-diode (RCD) snubbers. The main objective of this paper is to illustrate this issue and propose an alternate circuitry to reduce the current circulation and improve the conversion efficiency. The experimental results of a laboratory prototype are reported to verify the design.
  • Publication
    A Brief Review of Partial Discharge (PD) Detection, Recognition and Location Techniques for Liquid and Gas Insulated High Voltage Equipment
    ( 2019-01-01)
    Bohari Z.H.
    ;
    Isa M.
    ;
    Abdullah A.Z.
    ;
    Rahman A.A.
    High voltage (HV) equipment condition monitoring has become compulsory in the power utility supplier activity since the discovery of multiple failures on HV equipment during operation. The total cost of replacement and installation of HV equipment will cost millions of dollars and the loss of revenue of no supply period during the breakdown. Insulation parts in the HV equipment are the most important component that closely related to the reliability of the electrical system. The insulation part can be solid, liquid, or gaseous form eventually degraded due to existing stresses (electrical, chemical, and mechanical) in the equipment. One common phenomenon called Partial Discharge (PD) associated with HV equipment insulation degradation highlighted in this manuscript, and these situations intensively researched over the century. In this review paper, there are few conventional detections, recent detections, recognition techniques, and location techniques are discussed to explore the available methods to analyze further on the area for the future researcher. The objective of this review to present the latest PD associated techniques and facilitate and convey new information for a future research project.
  • Publication
    A compact high-gain parasitic patch antenna with electronic beam-switching
    ( 2019-02-01)
    Subramaniam D.
    ;
    Jusoh M.
    ;
    Sabapathy T.
    ;
    Osman M.N.
    ;
    Kamarudin M.R.
    ;
    Othman R.R.
    ;
    Awal M.R.
    A high beam steering antenna using HPND PIN Diode is proposed with a capability of steering its beam into three different directions-40 º, 0º and 40 º with respective switching condition. The reconfigurable parasitic antenna consists of a driven element and two reconfigurable parasitic elements, is designed with operating range of 9.5GHz. The parasitic elements act as reflectors or director depending on the switching conditions. Both parasitic elements are connected to ground plane via shorting pins. The reconfiguration is controlled by the two HPND PIN Diode switch that embeds to the parasitic element. An average gain value of 8dBi is achieved at all reconfiguration scenarios. All the simulated design has been carried out using CST software.
  • Publication
    A Compact MIMO Planar Inverted-F Antenna
    ( 2019-12-16)
    Najwa
    ;
    Nasrun Osman M.
    ;
    Jusoh M.
    ;
    Sabapathy T.
    ;
    Al-Bawri S.
    ;
    Azizan M.M.
    ;
    Ali T.
    In this work, a compact MIMO antenna is designed as a planar inverted F-antenna (PIFA) which can be used for smallest smartphones. The proposed antenna will cover the GSM frequency range of 900MHz and 1800MHz. Those dual bands are attained with high gain up to 4.7dB. Simulation and experimental results have been presented.
  • Publication
    A comparative study of different blood vessel detection on retinal images
    ( 2019-01-01)
    Mustafa W.A.
    ;
    Mahmud A.S.
    ;
    Aihsan M.Z.
    ;
    Saifizi M.
    ;
    Charin C.
    Detection of blood vessel plays an important stage in different medical areas, such as ophthalmology, oncology, neurosurgery, and laryngology. The significance of the vessel analysis was helped by the continuous overview in clinical studies of new medical technologies intended for improving the visualization of vessels. In this paper, several local segmentation techniques which include such as Vascular Tree Extraction, Tyler L. Coye and Line tracking, Kirsch's Template and Fuzzy C Mean methods were studied. The main objective is to determine the best approaches in order to detect the blood vessel on the degraded retinal input image (DRIVE dataset). A few Image Quality Assessment (IQA) was obtained to prove the effectiveness of each detection methods. Overall, the result of sensitivity highest came from Kirsch Templates (96.928), while specificity from Fuzzy C means (77.573). However, in term of accuracy average, the Line Tracking method is more successful compared to the other methods.
  • Publication
    A Comprehensive Review on Document Image (DIBCO) Database
    ( 2019-06-28)
    Mustafa W.A.
    ;
    Khairunizam W.
    ;
    Zunaidi I.
    ;
    Razlan Z.M.
    ;
    Shahriman A.B.
    One of the most significant current discussions in image processing is a document analysis. Now, many types of document database were established in order to address the issue of binarization effectiveness. In this paper, a comprehensive review of the document database was presented. Review based on an image from Document Image Binarization Contest (DIBCO) from 2013 to 2017 which consists of handwritten and printed image. The best algorithm for each year is discussed and analyzed. Based on the results, the technique using background estimation and stroke edges is better performance for the overall database. Besides, the method using the combination of Laplacian operator and canny edge detection also shows the successful result, especially in the printed image. Implications of the review give the direction for future binarization approach developments.
  • Publication
    A computational investigation of breast tumour on mammogram based on pattern of grey scale distribution
    ( 2019-01-01)
    Lim M.K.
    ;
    Khairunizam W.
    ;
    Mustafa W.A.
    Breast cancer is the utmost female tumor and the primary cause of deaths among female. Computer-Aided Detection (CAD) systems are widely used as a tool to detect and classify the abnormalities found in the mammographic images. A detection of breast tumor in a mammogram has been a challenge due to the different intensity distribution which leads to the misdiagnosis of breast cancer. This research proposes a dectection system that is capable to detect the presence of mass tumor from a mammogram image. A total of 160 mammogram images are acquired from Mammographic Image Analysis Society (MIAS) databse, which are 80 normal and 80 abnormal images. The mammogram images are rescaled to 300 x 300 resolution. The noise in the mammogram is suppressed by using a Wiener filter. The images are enhanced by using Power Law (Gamma) Transformation, ɣ = 2 for a better image quality. The greyscale information that contain tumor mass is extracted and used to model the proposed detection system by using 80% or 128 and of the total 160 mammogram images. The rest 20% or 32 mammogram images are used to test the performance of the proposed detection system. The experimental results show that performance of the proposed detection system has 90.93% accuracy.
  • Publication
    A concurrent dual-band CMOS low noise amplifier at 2.4/5.2 GHz for WLAN applications
    ( 2019-05-01)
    Murad S.
    ;
    Hasan A.
    ;
    Azizan A.
    ;
    Harun A.
    ;
    Karim J.
    This paper presents a concurrent dual-band CMOS low noise amplifier (LNA) at operating frequency of 2.4 GHz and 5.2 GHz for WLAN applications. The proposed LNA employed cascode common source to obtain high gain using 0.13-µm CMOS technology. The concurrent dual-band frequencies are matched using LC network band-pass and band-stop notch filter at the input and output stages. The filters help to shape the frequency response of the proposed LNA. The simulation results indicate that the LNA achieves a forward gain of 21.8 dB and 14.22 dB, input return loss of-18 dB and-14 dB at 2.4 GHz and 5.2 GHz, respectively. The noise figure of 4.1 dB and 3.5 dB with the input third-order intercept points 7 dBm and 10 dBm are obtained at 2.4 GHz and 5.2 GHz, respectively. The LNA dissipates 2.4 mW power at 1.2 V supply voltage with a chip size of 1.69 mm2.
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  • Publication
    A DNA based visual and colorimetric aggregation assay for the early growth factor receptor (EGFR) mutation by using unmodified gold nanoparticles
    ( 2019-08-01)
    Ramanathan S.
    ;
    Gopinath S.C.B.
    ;
    Arshad M.K.M.
    ;
    Poopalan P.
    ;
    Anbu P.
    A genomic DNA-based colorimetric assay is described for the detection of the early growth factor receptor (EGFR) mutation, which is the protruding reason for non-small cell lung cancer. A DNA sequence was designed and immobilized on unmodified gold nanoparticles (GNPs). The formation of the respective duplex indicates the presence of an EGFR mutation. It is accompanied by the aggregation of the GNPs in the presence of monovalent ions, and it indicates the presence of an EGFR mutation. This is accompanied by a color change from red (520 nm) to purple (620 nm). Aggregation was evidenced by transmission electron microscopy, scanning electron microscopy and atomic force microscopy. The limit of detection is 313 nM of the mutant target strand. A similar peak shift was observed for 2.5 μM concentrations of wild type target. No significant peak shift was observed with probe and non-complementary DNA. [Figure not available: see fulltext.].
  • Publication
    A dynamic K-means clustering for data mining
    ( 2019-02-01)
    Hossain M.Z.
    ;
    Akhtar M.N.
    ;
    Ahmad R.B.
    ;
    Rahman M.
    Data mining is the process of finding structure of data from large data sets. With this process, the decision makers can make a particular decision for further development of the real-world problems. Several data clusteringtechniques are used in data mining for finding a specific pattern of data. The K-means method isone of the familiar clustering techniques for clustering large data sets. The K-means clustering method partitions the data set based on the assumption that the number of clusters are fixed. The main problem of this method is that if the number of clusters is to be chosen small then there is a higher probability of adding dissimilar items into the same group. On the other hand, if the number of clusters is chosen to be high, then there is a higher chance of adding similar items in the different groups. In this paper, we address this issue by proposing a new K-Means clustering algorithm. The proposed method performs data clustering dynamically. The proposed method initially calculates a threshold value as a centroid of K-Means and based on this value the number of clusters are formed. At each iteration of K-Means, if the Euclidian distance between two points is less than or equal to the threshold value, then these two data points will be in the same group. Otherwise, the proposed method will create a new cluster with the dissimilar data point. The results show that the proposed method outperforms the original K-Means method.
  • Publication
    A efficacy of different buffer size on latency of network on chip (NoC)
    ( 2019-06-01)
    Zulkefli F.W.B.
    ;
    Ehkan P.
    ;
    Warip M.N.M.
    ;
    Phing N.Y.
    Moore's prediction has been used to set targets for research and development in semiconductor industry for years now. A burgeoning number of processing cores on a chip demand competent and scalable communication architecture such as network-on-chip (NoC). NoC technology applies networking theory and methods to on-chip communication and brings noteworthy improvements over conventional bus and crossbar interconnections. Calculated performances such as latency, throughput, and bandwidth are characterized at design time to assured the performance of NoC. However, if communication pattern or parameters set like buffer size need to be altered, there might result in large area and power consumption or increased latency. Routers with large input buffers improve the efficiency of NoC communication while routers with small buffers reduce power consumption but result in high latency. This paper intention is to validate that size of buffer exert influence to NoC performance in several different network topologies. It is concluded that the way in which routers are interrelated or arranged affect NoC’s performance (latency) where different buffer sizes were adapted. That is why buffering requirements for different routers may vary based on their location in the network and the tasks assigned to them.
  • Publication
    A Flexible UWB Antenna for Wearable Technologies Application
    ( 2019-07-01)
    Amir N.F.
    ;
    Jusoh M.
    ;
    Isa M.M.
    ;
    Sabapathy T.
    ;
    Al-Bawri S.S.
    ;
    Rahim H.A.
    ;
    Osman M.N.
    ;
    Yasin M.N.
    In this paper, wearable textile antenna is presented for detecting breast cancer in early stages. The proposed antenna is designed and optimized using a 0.5 flexible cotton material substrate to operate at UWB with a wider frequency range of 3 GHz - 10.5 GHz. In this paper, the performance of the antenna is investigated in terms of reflection coefficients, gain and radiation patterns by bending the structure in several different degrees. A line slot is used at the ground level to enhance the antenna resonate performance overdesigned spectrum. Moreover, the antenna has good gain and efficiency over the bandwidth of 3.47 dBi and 92.3 % respectively.
  • Publication
    A Fuzzy-Based Angle-of-Arrival Estimation System (AES) Using Radiation Pattern Reconfigurable (RPR) Antenna and Modified Gaussian Membership Function
    ( 2019-01-01)
    Jais M.I.
    ;
    Thennarasan Sabapathy
    ;
    Muzammil Jusoh
    ;
    R Badlishah Ahmad
    ;
    Jamaluddin M.H.
    ;
    Kamarudin M.R.
    ;
    Ehkan P.
    ;
    Murukesan Loganathan L.
    ;
    Soh P.J.
    Angle-of-arrival (AOA) estimation is an important factor in various wireless sensing applications, especially localization systems. This paper proposes a new type of AOA estimation sensor node, known as AOA-estimation system (AES) where the received signal strength indication (RSSI) from multiple radiation pattern reconfigurable (RPR) antennas are used to calculate the AOA. In the proposed framework, three sets of RPR antennas have been used to provide a coverage of 15 regions of radiation patterns at different angles. The salient feature of this RPR-based AOA estimation is the use of Fuzzy Inferences System (FIS) to further enhance the number of estimation points. The introduction of a modified FIS membership function (MF) based on Gaussian function resulted in an improved 85% FIS aggregation percentage between the fuzzy input and output. This later resulted in a low AOA error (of less than 5%) and root-mean-square error (of less than 8°).
  • Publication
    A general framework for improving electrocardiography monitoring system with machine learning
    ( 2019-03-01)
    Khairuddin A.M.
    ;
    Ku Nurul Fazira Ku Azir
    ;
    Eh Kan P.
    As one of the most important health monitoring systems, electrocardiography (ECG) is used to obtain information about the structure and functions of the human heart for detecting and preventing cardiovascular disease. Given its important role, it is vital that the ECG monitoring system provides relevant and accurate information about the heart. Over the years, numerous attempts were made to design and develop more effective ECG monitoring system. Nonetheless, the literature reveals not only several limitations in conventional ECG monitoring system but also emphasizes on the need to adopt new technology such as machine learning to improve the monitoring system as well as its medical applications. This paper reviews previous works on machine learning to explain its key features, capabilities as well as presents a general framework for improving ECG monitoring system.
  • Publication
    A hybrid approach of knowledge-driven and data-driven reasoning for activity recognition in smart homes
    ( 2019-01-01)
    Sukor A.
    ;
    Zakaria A.
    ;
    Rahim N.
    ;
    Kamarudin L.
    ;
    Setchi R.
    ;
    Nishizaki H.
    Accurate activity recognition plays a major role in smart homes to provide assistance and support for users, especially elderly and cognitively impaired people. To realize this task, knowledge-driven approaches are one of the emerging research areas that have shown interesting advantages and features. However, several limitations have been associated with these approaches. The produced models are usually incomplete to capture all types of human activities. This resulted in the limited ability to accurately infer users' activities. This paper presents an alternative approach by combining knowledge-driven with data-driven reasoning to allow activity models to evolve and adapt automatically based on users' particularities. Firstly, a knowledge-driven reasoning is presented for inferring an initial activity model. The model is then trained using data-driven techniques to produce a dynamic activity model that learns users' varying action. This approach has been evaluated using a publicly available dataset and the experimental results show the learned activity model yields significantly higher recognition rates compared to the initial activity model.
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