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Design of compact multi-mode microstrip resonator filters for dual-band application

10.11591/ijeecs.v13.i2.pp696-701
Nurshamimi Rosli , Siti Aminah Md Akhir , Siti Zuraidah Ibrahim , Nur Baya Mohd Hashim , Nurehansafwanah Khalid
This paper presents the design of compact multi-mode microstrip resonator filters for dual-band application. The design is simulated using Advanced Design System (ADS) 2016 software. The benefit of the proposed filter is found to have a dual-mode frequency, where the odd-mode resonant frequency is the fundamental frequency represented by the length of the resonator while the even-mode resonant frequency is represented by the length of the stub. To validate the design, a prototype is fabricated on Rogers RO4003C substrate and measured using PNA Network Analyzer.
Volume: 13
Issue: 2
Page: 696-701
Publish at: 2019-02-01

A compact high-gain parasitic patch antenna with electronic beam-switching

10.11591/ijeecs.v13.i2.pp551-555
D. Subramaniam , M. Jusoh , T. Sabapathy , M. N. Osman , M. R. Kamarudin , R. R. Othman , M. R. Awal
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.
Volume: 13
Issue: 2
Page: 551-555
Publish at: 2019-02-01

Load balancing clustering on moodle LMS to overcome performance issue of e-learning system

10.12928/telkomnika.v17i1.10284
Mujiono; Universitas Mercu Buana Sadikin , Raka; Universitas Mercu Buana Yusuf , Arif Rifai; Universitas Mercu Buana D.
In dealing with the rapid growth of digitalization, the e-learning system has become a mandatory component of any Higher Education (HE) to serve academic processes requests. Along with the increasing number of users, the need for service availability and capabilities of eLearning are increasing day by day. The organization should always look for strategies to keep the eLearning always able to meet these demands. This report presents the implementation of Load Balancing Clustering (LBC) mechanism applied to Moodle LMS in an HE Institution to deal with the poor performance issues. By utilizing existing tools such as HAProxy and keepalived, the implemented LBC configuration delivers a qualified e-learning system performance. Both qualitative and quantitative parameters convince better performance than before. In four months of the operation there is no user complaint received. Meanwhile, in the current semester has been running for two months, the up-time is 99.8 % of 52.685 minutes operational time.
Volume: 17
Issue: 1
Page: 131-138
Publish at: 2019-02-01

A colour-based building recognition using support vector machine

10.12928/telkomnika.v17i1.11609
Mas Rina; Universiti Putra Malaysia Mustaffa , Loh Weng; Universiti Putra Malaysia Yee , Lili Nurliyana; Universiti Putra Malaysia Abdullah , Nurul Amelina; Universiti Putra Malaysia Nasharuddin
Many applications apply the concept of image recognition to help human in recognising objects simply by just using digital images. A content-based building recognition system could solve the problem of using just text as search input. In this paper, a building recognition system using colour histogram is proposed for recognising buildings in Ipoh city, Perak, Malaysia. The colour features of each building image will be extracted. A feature vector combining the mean, standard deviation, variance, skewness and kurtosis of gray level will be formed to represent each building image. These feature values are later used to train the system using supervised learning algorithm, which is Support Vector Machine (SVM). Lastly, the accuracy of the recognition system is evaluated using 10-fold cross validation. The evaluation results show that the building recognition system is well trained and able to effectively recognise the building images with low misclassification rate.
Volume: 17
Issue: 1
Page: 473-480
Publish at: 2019-02-01

Optical millimeter wave generation utilizing stimulated brillouin scattering for radio over fiber system

10.11591/ijeecs.v13.i2.pp818-824
M.M.H Husaini , C.B.M Rashidi , SN Azemi , S.A Aljunid , M.S Anuar
Optical millimeter-wave signal generation in Radio over Fiber (RoF) based on external modulators using different modulation schemes such as Single-Sideband (SSB), Double-Sideband (DSB) are experimentally compared. The major fallout for external modulation scheme system performance to downgrade is due to dispersion and the fading effect in optical signal generation while generating high Bit Error Rate (BER) when involving long distance delivery.  In this work, we proposed mm-wave signal utilize Stimulated Brillouin Scattering (SBS) scheme which  indicates the best performance amongst the scheme based on simulation that it achieves to propagate longest of distance over fiber, highest receiver sensitivity, the lowest BER and coherence of Mach-Zehnder Modulator (MZM) extinction ratio. Mm-wave signal of 40 Ghz and 10 Gb/s data rate was generated with the plotting of eye diagram.
Volume: 13
Issue: 2
Page: 818-824
Publish at: 2019-02-01

Squirrel cage induction motor scalar control constant V/F analysis

10.12928/telkomnika.v17i1.8818
K. A. M.; Universiti Teknikal Malaysia Melaka Annuar , M. R.; Universiti Teknikal Malaysia Melaka Sapiee , Rozilawati M.; Universiti Teknikal Malaysia Melaka Nor , M. S. M.; Universiti Teknikal Malaysia Melaka Azali , M. B. N.; Universiti Teknikal Malaysia Melaka Shah , Sahazati Md.; Universiti Teknikal Malaysia Melaka Rozali
In constant V/f control technique it is assume that the stator resistance and leakage inductance drops are negligible, especially at high speed and small load. In other words, the back emf is comparatively large at high speed and hence these voltage drops can be neglected. By maintaining constant V/f, constant Eg/f and hence constant air-gap flux is assumed. This assumption is however invalid at low speeds since a significant voltage drop appears across the stator impedance. The terminal voltage, V no longer approximates  ag. By using MATLAB Simulink, the open-loop constant V/f is simulated. It is shown that the performance of the drive deteriorates at low speeds. The improvement in the performance by applying voltage boost is shown and discussed.
Volume: 17
Issue: 1
Page: 417-424
Publish at: 2019-02-01

Transistor mismatch effect on common-mode gain of cross-coupled amplifie

10.12928/telkomnika.v17i1.11587
Zainul; Brawijaya University Abidin , Eka; Brawijaya University Maulana , Ramadhani Kurniawan; Brawijaya University Subroto , Wijono; Brawijaya University Wijono
In this paper, the analytical approach of MOS transistor mismatch effect on common-mode gain of cross-coupled amplifier is presented. Transconductance (MOS transistor parameter) mismatch effect on common-mode gain of cross-coupled amplifier was analyzed. This study was started with mathematical derivation for representing the mismatch effect of transconductance between 2 differential pairs of crosscoupled amplifier due to common-mode voltage. The derivation result was simulated based on Monte Carlo simulation with random transconductance mismatch rate from 0.05% until 1%. The common-mode gain increases 36.9 dB and average common-mode gain is -81.1 dB. The transconductance mismatch rate increases followed by increase in common-mode gain. The results can be used by circuit designers to design analog circuits, especially operational amplifier used for biosignals processing to minimize the common-mode gain of their circuits. This research presents aid to circuit designers to improve their circuits performance.
Volume: 17
Issue: 1
Page: 448-452
Publish at: 2019-02-01

Big 5 ASEAN capital markets forecasting using WEMA method

10.12928/telkomnika.v17i1.11625
Seng; Universitas Multimedia Nusantara Hansun , Marcel Bonar; Universitas Multimedia Nusantara Kristanda , P. M.; Universitas Multimedia Nusantara Winarno
ASEAN through ASEAN Economics Community (AEC) 2020 treaty has proposed financial integration via capital markets integration in order to aim comprehensive ASEAN economic integration. Therefore, the need to have a proper prediction of ASEAN capital market becomes a major issue. In this study, we took big 5 ASEAN capital markets, i.e. Straits Times Index (STI), Kuala Lumpur Stock Exchange (KLSE), Stock Exchange of Thailand (SET), Jakarta Stock Exchange (JKSE), and Philippine Stock Exchange (PSE) to be forecasted using WEMA method. Weighted Exponential Moving Average (WEMA) is a new hybrid moving average method which combines the weighting factor calculation in Weighted Moving Average (WMA) with the procedure of Exponential Moving Average (EMA). WEMA has successfully been implemented and used to forecaste discrete time series data, but never being used to forecast ASEAN capital markets. In this study, we took further action by implementing the WEMA method with brute force approach for scaling factor tuning on big 5 ASEAN capital markets. From the experimental results, we found that WEMA has successfully forecasted all those exchanges. By looking at the forecast error measurement, it gives the best performance on PSE and worst performance on SET dataset among all datasets being considered in this study.
Volume: 17
Issue: 1
Page: 314-319
Publish at: 2019-02-01

Classification of neovascularization using convolutional neural network model

10.12928/telkomnika.v17i1.11604
Wahyudi; University of Airlangga Setiawan , Moh. Imam; University of Airlangga Utoyo , Riries; University of Airlangga Rulaningtyas
Neovascularization is a new vessel in the retina beside the artery-venous. Neovascularization can appear on the optic disk and the entire surface of the retina. The retina categorized in Proliferative Diabetic Retinopathy (PDR) if it has neovascularization. PDR is a severe Diabetic Retinopathy (DR). An image classification system between normal and neovascularization is here presented. The classification using Convolutional Neural Network (CNN) model and classification method such as Support Vector Machine, k-Nearest Neighbor, Naïve Bayes classifier, Discriminant Analysis, and Decision Tree. By far, there are no data patches of neovascularization for the process of classification. Data consist of normal, New Vessel on the Disc (NVD) and New Vessel Elsewhere (NVE). Images are taken from 2 databases, MESSIDOR and Retina Image Bank. The patches are made from a manual crop on the image that has been marked by experts as neovascularization. The dataset consists of 100 data patches. The test results using three scenarios obtained a classification accuracy of 90%-100% with linear loss cross validation 0%-26.67%. The test performs using a single Graphical Processing Unit (GPU).
Volume: 17
Issue: 1
Page: 463-472
Publish at: 2019-02-01

A wideband reflectarray antenna based on organic substrate materials

10.12928/telkomnika.v17i1.9593
H. I.; University Tun Hussein Onn Malaysia (UTHM) Malik , M. Y.; University Tun Hussein Onn Malaysia (UTHM) Ismail , Sharmiza; Forest Research Institute Malaysia (FRIM) Adnan , S. R.; University Tun Hussein Onn Malaysia (UTHM) Masrol , N.; University Tun Hussein Onn Malaysia (UTHM) Nafarizal
Significant improvements in terms of bandwidth of reflectarray antennas have been achieved by introduction of innovative paper substrate dielectric materials. Three differently custom composed organic dielectric substrates have been characterized for dielectric properties using a broadband technique based on open ended coax cable method. The substrates show low dielectric permittivities of 1.81, 1.63 and 1.84 along with a loss tangent of 0.053, 0.047 and 0.057. Validation of using the proposed substrates for reflectarray antenna was done by modelling and fabricating reflectarray unit elements on the three substrates. Scattering parameter analysis of unit reflectarray elements show encouraging results with a broadband frequency response of 340 MHz at a phase gradient of 0.14 º/MHz. Thus the proposed substrate could serve exceptionally to address the narrow bandwidth problem in reflectarray antennas.
Volume: 17
Issue: 1
Page: 8-14
Publish at: 2019-02-01

Shape analysis for classification of breast nodules on digital ultrasound images

10.11591/ijeecs.v13.i2.pp837-844
Hanung Adi Nugroho , Hesti Khuzaimah Nurul Yusufiyah , Teguh Bharata Adji , Widhia K.Z Oktoeberza
One of the imaging modalities for early detection of breast cancer malignancy is ultrasonography (USG).  The malignancy can be analysed from the characteristic of nodule shape.  This study aims to develop a method for classifying the shape of breast nodule into two classes, namely regular and irregular classes.  The input image is pre-processed by using the combination of adaptive median filter and speckle reduction bilateral filtering (SRBF) to reduce speckle noises and to eliminate the image label.  Afterwards, the filtered image is segmented based on active contour followed by feature extraction process.  Nine extracted features, i.e. roundness, slimness and seven features of invariant moments, are used to classify nodule shape using multi-layer perceptron (MLP).  The performance of the proposed method is evaluated using 105 breast nodule images which comprise of 57 regular and 48 irregular nodule images.  The results of classification process achieve the level of accuracy, sensitivity and specificity at 96.20%, 97.90% and 94.70%, respectively.  These results indicate that the proposed method successfully classifies the breast nodule images based on shape analysis.
Volume: 13
Issue: 2
Page: 837-844
Publish at: 2019-02-01

An angle speed and thrust relationship of the rotor system in the quadcopter aircraft

10.11591/ijeecs.v13.i2.pp469-474
Al Al , Arfita Yuana Dewi , Antonov Bachtiar , Dwi Harinita
Utilizing Quadcopter were still many obstacles such as; plane easy to fall; the battery is not durable; vulnerable to weather conditions and others. The research and development has grown to improve aircraft facilities and capabilities. Many parameters related to aircraft lift capability factors; fly long; flying high; type of motor; the type of propeller: including the sensors and control systems used. This study was to find the relationship between changes in the BLDC motor voltage source to the rotor angle velocity (ω); rotor speed to rotor lift (Ft);  wind speed to rotor lift; push the following rotor (Ct). Empirical testing was conducted in the laboratory to find the relationship of these parameters. The results data show that; the lift power generated with rotational speed was not proportional, non linearity occurs when the rotor was released from the self and starts pulling the strain gauge when the rotation speed reaches around 65 rps. Once the rotation speed of the rotor is able to reach up to 1.5 Newton lift then the thrust rising trend sharply increasing toincreasing of the rotor speed. A motor hade 1200 KV and blade with a radius of 0.12 m, then obtained thrust (Ct) of 1.732.
Volume: 13
Issue: 2
Page: 469-474
Publish at: 2019-02-01

Performance analysis of spectral/spatial of OCDMA system using 2D hybrid ZCC/MD code

10.11591/ijeecs.v13.i2.pp569-574
Rima. Matem , S. A. Aljunid , M. N. Junita , C.B.M Rashidi , Israa Shihab Aqrab
This paper proposes a new spectral/spatial code for Spectral Amplitude Coding in Optical Coding Division Multiple Access (SAC-OCDMA) called two-Dimensional hybrid ZCC/MD code. The new code combines two of the one –dimensional codes which are Zero Cross Correlation (1D ZCC) and Multi-Diagonal code (1D MD). Moreover, it produces a zero cross correlation property for each code. The main goal of this proposed code is to mitigate Phase Induced Intensity Noise and eliminate Multiple Access Interference (MAI). This proposed code can provide a better performance comparing to other codes as 2D FCC/MDW and 2D DPDC according to the obtained numerical analysis.
Volume: 13
Issue: 2
Page: 569-574
Publish at: 2019-02-01

Analysis theorem of unique common fixed point for four maps based on partial –b– metric spaces

10.11591/ijeecs.v13.i2.pp657-664
Ban Hasan , Hayder Abdulameer Abbas
In this paper, An important definitions are to be used to prove the existence of a common fixed point theorem for four mappings incomplete,  partial – b – metric spaces, as well as prove a unique common fixed point by assuming another point and getting that, these points are finally equal. We presented an example thus enhancing us the outcome.
Volume: 13
Issue: 2
Page: 657-664
Publish at: 2019-02-01

Allocation of distributed generation and capacitor banks in distribution system

10.11591/ijeecs.v13.i2.pp437-446
Olatunde Oladepo , Hasimah Abdul Rahman
Voltage profile and power losses on the distribution system is a function of real and imaginary power loading condition. This can be effectively managed through the controlled real and reactive power flow by optimal placement of capacitor banks (CB) and distributed generators (DG). This paper presents adaptive Particle Swarm Optimization (MPSO) to efficiently tackle the problem of simultaneous allocation of DG and CB in radial distribution system to revamp voltage magnitude and reduce power losses. The modification to the conventional PSO was achieved by replacing the inertial weight equation (W) in the velocity update equation base on the particle best experience in the previous iteration. The inertial weight equation is designed to vary with respect to the iteration value in the algorithm. The proposed method was investigated on IEEE 30-bus, 33-bus and 69-bus test distribution systems. The results shows a significant improvement in the rate of convergence of APSO, improved voltage profile and loss reduction.
Volume: 13
Issue: 2
Page: 437-446
Publish at: 2019-02-01
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