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Publisher: Universitas Ahmad Dahlan   (Total: 13 journals)   [Sort by number of followers]

Showing 1 - 13 of 13 Journals sorted alphabetically
Ahmad Dahlan J. of English Studies     Open Access   (Followers: 1)
Berkala Fisika Indonesia     Open Access  
HUMANITAS (Jurnal Psikologi Indonesia)     Open Access   (Followers: 4)
Intl. J. of Advances in Intelligent Informatics     Open Access   (Followers: 5)
J. of Education and Learning     Open Access   (Followers: 10)
J. of Education, Health and Community Psychology     Open Access   (Followers: 7)
Jurnal Ilmiah AdMathEdu     Open Access  
Jurnal Informatika     Open Access   (Followers: 1)
Jurnal Kesehatan Masyarakat (J. of Public Health)     Open Access   (Followers: 2)
Media Farmasi     Open Access  
Pharmaciana     Open Access  
Psikopedagogia : Jurnal Bimbingan dan Konseling     Open Access   (Followers: 1)
TELKOMNIKA (Telecommunication, Computing, Electronics and Control)     Open Access   (Followers: 8, SJR: 0.211, h-index: 8)
Journal Cover TELKOMNIKA (Telecommunication, Computing, Electronics and Control)
  [SJR: 0.211]   [H-I: 8]   [8 followers]  Follow
  This is an Open Access Journal Open Access journal
   ISSN (Print) 1693-6930 - ISSN (Online) 2302-9293
   Published by Universitas Ahmad Dahlan Homepage  [13 journals]
  • A Three-Phase Grid-Connected PV System Based on SAPF for Power Quality

    • Authors: Rachid Belaidi, Ali Haddouche, Djamila Ghribi, M. Mghezzi Larafi
      Abstract: This paper proposes a combined system of three-phase four-wire shunt active power filter (SAPF), and photovoltaic generator (PVG), to solve the power quality problems such as harmonic currents, poor power factor, and unbalanced load. In addition, the proposed system can inject the issued energy from the PVG into the utility grid. To increase the efficiency of the PVG and extract the maximum photovoltaic (PV)  power under variable atmospheric conditions, a maximum power point tracking (MPPT) technique based on perturb and observe (P&O) is implemented in the DC/DC boost converter. The effectiveness of the proposed PVG-SAPF (PVG and SAPF) based on the use of synchronous reference frame theory (SRF theory) under unbalanced nonlinear load. The proposed PVG-SAPF is validated through numerical simulations using Matlab/Simulink software. The simulation results show the effectiveness of the proposed PVG-SAPF.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5439
      Issue No: Vol. 15, No. 3 (2017)
  • A Proposed Design of Unit Cell of Metamaterial for 5G Mobile Communication

    • Authors: Jamal Mohammed Rasool
      Abstract: In this manuscript a design of metamaterial unit cells which are new artificial materials made of periodic arrangement much smaller than the guided wavelength, are proposed which are suitable to work for 5G mobile communication working with millimeter frequency band at 28 GHz due the high demand for the frequency spectrum for mobile networks .The structures of unit cells were simulated using High Frequency Structure Simulator HFSS software. The design starts with the metamaterial structure which is composed of double rectangular (DRR) and   circular split ring resonator (DSRR). The results of simulation showed very good results such as wide operating frequency band which is 1.34   GHz with very law radiation losses the unit cell designed to overrun the radiation losses which are appear with the work of metamaterials.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6079
      Issue No: Vol. 15, No. 3 (2017)
  • New Miniature Planar Microstrip Antenna Using DGS for ISM applications

    • Authors: R. Er-rebyiy, J. Zbitou, M. Latrach, A. Tajmouati, A. Errkik, L. EL Abdellaoui
      Abstract: The aim of this paper is to use defected ground structures (DGS) in order to miniaturize a microstrip patch antenna. The DGS structure is integrated in the ground plane to improve the performance of the planar antenna, and shifted the resonance frequency from 5.8 GHz to 2.5 GHz, with a miniaturization up to 83%.The antenna is designed, optimized, and miniaturized by using the CST MW-studio, mounted on an FR-4 substrate having a dielectric constant 4.4, a loss tangent tan (ɸ) = 0.025,thickness of 1.6 mm with the whole area of 34 X 34 mm2.The proposed antenna is suitable for ISM (Industrial, Scientific and Medical) applications at 2.5 GHz with S11 ≤ (-10) dB. The antenna is fed by 50ohm input impedance and it has good performances in terms of matching input impedance and radiation pattern. The proposed antenna was fabricated and tested.Simulation and measurement results are in good agreement.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6864
      Issue No: Vol. 15, No. 3 (2017)
  • Fuzzy Logic Implementation with MATLAB for PV-Wind Hybrid System

    • Authors: Alias Khamis, Mohd Ruddin Ab. Ghani, Chin Kim Gan, Mohd Shahrieel Mohd Aras, Muhamad Fiqry Khamis, Tole Sutikno, Jano Zanariah
      Abstract: The development of hybrid renewable energy sources is vital in power generation. This study focused on design of fuzzy logic control on hybrid PV/Wind system in order to improve the speed of  DC motor.  The fuzzy logic control based on battery management system has been designed for effective power utilization and improvement of the DC motor speed performance. In battery management system, a control was proposed to operate the charging and discharging mode of battery during non-linear power generation. While the battery would charge whenever the renewable energy power was greater than consumer load power, the battery would discharge whenever the renewable energy power was less than the consumer load power. DC motor speed control, included the simulation, implementation of fuzzy logic controller to DC motor and comparison between PID controller and Fuzzy Logic Controller. The proposed model was simulated using Matlab environment and the results was analyzed. Finally, simulation results were evaluated and validated to determine the effectiveness of the proposed controller.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6099
      Issue No: Vol. 15, No. 3 (2017)
  • Agent Based Modeling on Dynamic Spreading Dengue Fever Epidemic

    • Authors: Heti Mulyani, Taufik Djatna, Imas Sukaesih Sitanggang
      Abstract: Agent based model (ABM) is a computational model for simulation, behavioral representation and interaction of autonomous agents. The main problem definition related to how to make a dynamic model of dengue fever with consideration of their behavioral and interaction agent. This paper aims to develop interactive behavioral agents and related simulation models for such dynamic spreading dengue fever epidemic. This model construction consists of two agents, namely a human agent as a host and mosquito as a vector, where temperature and humidity are the environmental parameters. These environmental parameters deployed data and information from National Meteorology Climatology and Geophysics agency and supported by recent community health data of Bogor region. The verification stage evaluated model performance of two periods between January to June and between July to December 2015 showed the fitness of the model. During simulation stage where 100 humans agent and 10 mosquitoes agent were observed, indicating the decreasing of mosquito by 26.3% and the number of infected human decrease to 16% from the period of January until June to July until December 2015  respectively. These evaluation results  showed that the agent based model results succeeded to follow a similar trend of decreasing pattern as actual data.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.4511
      Issue No: Vol. 15, No. 3 (2017)
  • Use of Automation Codecs Streaming Video Applications Based on Cloud

    • Authors: Hero Wintolo, Anggraini Kusumaningrum, Handoko Widya Kusuma
      Abstract: Streaming technology is currently experiencing a great progress. Faster internet more users streaming. Streaming services that exist today there are still weaknesses in both the upload speed, streaming speed and limited types of video extensions that can be played. To resolve these problems then made a video streaming service based local area network with a system of cloud computing that can work effectively in terms of upload speeds, streaming and variations in video formats. Video streaming application is classified as a service IaaS (Infrastructure as a Service Cloud) in cloud computing. On the use of streaming applications the user does not need to convert the video, with the purpose of uploading process can be faster and applications can play a variety of video formats.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.2810
      Issue No: Vol. 15, No. 3 (2017)
  • Research and Application of Development Model of Information Service for
           IOT of Oil and Gas Production Based on Cloud Architecture

    • Authors: Haili Wu, Renbin Gong, Congbin Wang, Lei Gong
      Abstract: On completion of oil and gas production IOT system application system needs expanding and secondary problems such as software development integration service, this paper proposes a scalable cloud platform(called A11-PaaS) based on middleware and ESB(Enterprise service bus). The platform realizes that managmant of ESB, controls the service request access on the ESB with the LDAP, use the WAS profile as a sandbox for the development, combine with the Maven plug-in and Nexus, realize the unified management of the secondary development, testing, and deployment of the new system and achieve the purpose of rapid development. The platform has been deployed in some oil company, the experimental results show that this technology has achieved rapid development, integrated the web service from IOT system, and provide effective method to integrate other application system.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5510
      Issue No: Vol. 15, No. 3 (2017)
  • Miniaturization of Resonator based on Moore Fractal

    • Authors: E. Mohd, S. H. Dahlan
      Abstract: This paper presents the simulation and fabrication of miniaturized half wavelength resonator design using Moore fractal iteration technique. These resonators have been prepared for wireless application at a centre frequency of 2.45GHz using a substrate with dielectric constant of 2.2. The size and performance are compared with the conventional half wavelength open line resonator. It can be shown that the Moore fractal iteration technique able to reduce 46% of the size of conventional half wavelength resonator through first iteration, and 30% through second iteration while maintaining the resonance performance. The resonators have been fabricated using conventional printed circuit board facilities not specialized in microwave devices. However, the unloaded Q-value of the Moore structure generally much lower compared the open line type.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.7211
      Issue No: Vol. 15, No. 3 (2017)
  • Effect of Pump Dithering at Each Stage of Cascaded Fiber Optical
           Parametric Amplifier

    • Authors: Fatin Nabilah Mohamad Salleh, Nor Shahida Mohd Shah, Nurulanati Othman, Rahmat Talib, Munirah Ab. Rahman
      Abstract: Cascaded fiber optical parametric amplifier (FOPA) can enhance gain and bandwidth. The gain and bandwidth can be further enhanced by dithering the FOPA pump. However, to our knowledge, the effects of a pump dithering at every stage of cascaded FOPA have not been discussed. The study of performance at every stage of cascaded FOPA is quite interesting and beneficial in designing the system. Here, we analyzed, using OptiSystem software, each stage of a cascaded FOPA, when there was a pump dithering and not. The results showed that the pump dithering enhanced the gain and broaden the bandwidth at every stage. The gain and bandwidth obtained with the pump dithering were 27 dB and 20 nm, respectively. On the other hand, when there was no pump dithering, the gain and bandwidth were 9 dB and 12 nm, respectively.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.7212
      Issue No: Vol. 15, No. 3 (2017)
  • An Upgraded Transverse Electromagnetic Parallel Plates for Dielectric

    • Authors: S. K. Yee, R. Padu, C. K. Sia, X. T. I. Ngu, S. H. Dahlan, M. A. Azlan
      Abstract: A new version of transverse electromagnetic parallel plates with irregular plates’ width and plate separation has been developed for dielectric measurement. The separation between the plates are supported by four rectangular Teflon block and 1 mm of groove is proposed at the center of the upper plate to maintain the measurement repeatability. The groove enables the samples which are slightly higher than 2 cm to be fitted well between the plates without introducing extra force to the plates. The performance of both parallel plates has been compared in the frequency range from 100 MHz to 1.1 GHz. It is found that the upgraded parallel plate offers better return loss and insertion loss above 500 MHz compared to the previous parallel plate. It is reported from this work that the return loss of the parallel plate must be lower than -15 dB in order to achieve accurate dielectric constant. However, the insertion loss of the parallel plates does not influence the real permeability significantly. The upgraded TEM parallel plate produces a consistent reading with a standard deviation of less than 0.05 above frequency 200 MHz. The dielectric measurement of Polypropylene (PP) has proven the capability of this upgraded TEM parallel plate.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.7213
      Issue No: Vol. 15, No. 3 (2017)
  • Flexible Wearable Antenna on Electromagnetic Band Gap using PDMS substrate

    • Authors: Adel Y. I. Ashap, Z. Z. Abidin, S. H. Dahlan, H. A. Majid, S. K. Yee, Gameel Saleh, Norun Abdul Malek
      Abstract: A robust and low-profile electromagnetic band-gap (EBG) based on flexible wearable antenna covering 2.4 GHz frequency band is presented. The incorporated EBG with antenna reduces the radiation into the human body around 17 dB and decreases the impacts of frequency detuning. The overall dimension of the antenna integrated with EBG is 56 x 56 x 4 mm3 with relative impedance bandwidth of 8.3% is achieved. The proposed design has improved the gain up to 7 dBi. Specific absorption rate (SAR) assessment is also studied to certify the performance of the antenna when it is located proximity to human tissue. The flexible antenna with aforementioned performances could be chosen as a good candidate for integration into a range of wearable devices for medical application.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.7214
      Issue No: Vol. 15, No. 3 (2017)
  • Numerical Simulation of Highly-Nonlinear Dispersion-Shifted Fiber Optical
           Parametric Gain Spectrum with Fiber Loss and Higher-Order Dispersion

    • Authors: K. G. Tay, N. Othman, N. S. M. Shah, N. A. Cholan
      Abstract: The previous study investigated the fiber parameters on the analytical one-pump fiber optical para-metric amplifier (FOPA) gain spectrum of a loss-free highly-nonlinear dispersion-shifted fiber (HNL-DSF) and got the optimum results for each parameter. However, the FOPA gain of the combination of all the optimum values of the considered parameters was not reported. Hence, this paper intends to investigate the analyti-cal FOPA gain of the combination of all the optimum values of the considered parameters from the previous study. Later, the analytical gain was compared with the numerical gain from the fourth-order Runge-Kutta (RK4) method and Matlab built-in function, ode45. Next, the effect of fiber loss and higher order dispersion coefficients such as fourth and sixth-order dispersion coefficients were studied. It is found that RK4 gives a smaller error and the gain reduces while the bandwidth remains same in presence of fiber loss. The fourth-order dispersion coefficient broadens the bandwidth a bit while maintaining the gain and there are two narrow-band gains generated to the left and right-side of the broad-band gain. The sixth-order dispersion coefficient just shifts the two narrow-band gains toward or away from the broadband gain depending on the positive or negative signs of the sixth-order dispersion coefficient.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.7215
      Issue No: Vol. 15, No. 3 (2017)
  • Microstrip to Parallel-Strip Nonlinear Transition Balun with Stubs and DGS
           for UWB Dipole Antenna

    • Authors: S. A. Hamzah, S. Mohd Shah, H. Majid, K. N. Ramli, M. S. Zainal, L. Audah, S. Z. Sapuan, A. Ubin, M. Esa, N. N. Nik Abd Malik
      Abstract: Three tapered baluns with nonlinear transition are developed for harmonic suppression in dipole antenna. The first balun consists of an exponential profile with the size of a quarter–wavelength for both the height and width with a wideband characteristic. However, for some applications such as narrowband harmonic suppression antennas and wideband-to-narrowband reconfigurable antennas, the suppression of higher operating band is desired. By employing stubs-filter and a defected ground structure (DGS), two narrowband tapered baluns are produced. They are named as an exponential balun-stub and an exponential balun-DGS, respectively, that operate from 1 to 2 GHz. A simulated and measured results that based on the reflection coefficient is found to be better than -10 dB from 1 to 2 GHz. The employment of the stubs and DGS have enabled these baluns to have the capability to reject the unwanted higher frequency band from 2.0 to 10 GHz. Finally, the proposed baluns are employed as a feeding circuit for an ultra wideband (UWB) circular dipole antenna that produces a reasonable outcome.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.7216
      Issue No: Vol. 15, No. 3 (2017)
  • Enhanced Payload Data Reduction Approach for Cluster Head (CH) Nodes

    • Authors: N. A. M. Alduais, J. Abdullah, A. Jamil
      Abstract:  In this paper, we suggested two approaches to minimizing the CH packet size by considering the accuracy of prediction of sensed data at the base station. The proposed coding schemes based relative difference (CS-RD) and based the factor of precision (CS-FP) instead of the absolute change method that has been used in recent work. The aim is to enhance the accuracy of prediction data at the base station. Therefore, the performance metric was evaluated in term of the accuracy of prediction data at the base station. Simulation results showed that the proposed approaches performed better in term of the accuracy of prediction data at the base station. Specifically, the distortion percentage and average Absolut error in the CS-RD and CS-FP method decreased by 50% and 88% better than the current new aggregation method (ADATDC). However, our proposed CS-FP showed a low reduction ratio for some states.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.7217
      Issue No: Vol. 15, No. 3 (2017)
  • Integrated Open Loop Resonator Filter Designed with Notch Patch Antenna
           for Microwave Applications

    • Authors: D. Azra Awang Mat, N. Syuhada Hasim, Nurmiza Othman, Amira Amran, D. Norkhairunnisa Abang Zaidel, A. S. Wani Marzuki, Shafrida Sahrani, Kismet anak Hong Ping, Rohana Sapawi
      Abstract: This paper presented the design of integrated open loop resonator bandpass filter with notch type antenna for the use in microwave applications. Chebyshev type filter is selected as the filter characteristics and cascaded design with the antenna to produce a single module, Integrated Filter Antenna (IFA). Special feature of the antenna is the implementation of notch on the patch antenna to improve the efficiency. IFA is then simulated in electromagnetic simulation tool, Agilent Advance Design System (ADS) version 2016 and measured using R&S Vector Network Analyzer. It shows that the proposed IFA produced good measured return loss >-30dB with both vertical and horizontal gain of 9.11dBi and 8.01dBi respectively.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.7218
      Issue No: Vol. 15, No. 3 (2017)
  • The Correlation of Statistical Image and Partial Discharge Pulse Count of
           LDPE-NR Composite

    • Authors: Aulia Aulia, Zulkarnain Abdul Malek, Yanuar Zulardiansyah Arief, Eka Putra Waldi
      Abstract: High voltage insulation must be designed in such a way that it is very resistant to ageing including that from partial discharge (PD).  Many studies were previously carried out on composites based on low density polyethylene (LDPE). However, the use of natural rubber (NR) is relatively new.  Furthermore, the PD resistant performance of the composites is yet to be extensively researched.  This work aims to analyzee the correlation between PD pulse count and its related image to interpreting the effect of PD signals. The results show there is a strong correlation between PD pulse count and the statical image. The results indicate that the surface image statistical analysis can be used as a tool to justify the total of the PD pulse count on the surface for different samples of composite.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5149
      Issue No: Vol. 15, No. 3 (2017)
  • Neural Network-Based Stabilizer for the Improvement of Power System
           Dynamic Performance

    • Authors: Rudy Gianto, Kho Hie Khwee
      Abstract: This paper develops an adaptive control coordination scheme for power system stabilizers (PSSs) to improve the oscillation damping and dynamic performance of interconnected multimachine power system. The scheme was based on the use of a neural network which identifies online the optimal controller parameters. The inputs to the neural network include the active- and reactive- power of the synchronous generators which represent the power loading on the system, and elements of the reduced nodal impedance matrix for representing the power system configuration. The outputs of the neural network were the parameters of the PSSs which lead to optimal oscillation damping for the prevailing system configuration and operating condition. For a representative power system, the neural network has been trained and tested for a wide range of credible operating conditions and contingencies. Both eigenvalue calculations and time-domain simulations were used in the testing and verification of the performance of the neural network-based stabilizer
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.3875
      Issue No: Vol. 15, No. 3 (2017)
  • Thermal Condition and Losses in Ultra-High-Speed Generators

    • Authors: Flur Ismagilov, Viacheslav Vavilov, Ruslan Karimov, Denis Gusakov
      Abstract: In this paper ultra-high-speed generators operated in intermittent periodic and short-term mode were considered. Experimental studies of losses depending on frequencies in the magnetic core of microelectromechanical energy converters made from amorphous steel were made. Dependence of the flux density from the temperature in the air gap of the experimental layout of high-coercivity permanent magnets was obtained. Computer modeling of the magnetic field distribution on the cross section of the stator magnetic core of microelectromechanical energy converters were made in the software package Ansoft Maxwell. Dependence of friction losses of the rotor around the air from the air temperature was obtained. Comparisons of losses and efficiency of microelectromechanical energy converters in a cold state and after 10 minutes of operation without cooling were made.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6365
      Issue No: Vol. 15, No. 3 (2017)
  • Noise Analysis in VLC Optical Link based Discrette OP-AMP Trans-impedance
           Amplifier (TIA)

    • Authors: Syifaul Fuada, Angga Pratama Putra, Trio Adiono, Yulian Aska
      Abstract: To design Visible Light Communication (VLC) system, there are several requirements that needs to be met. One of the requirements is an active component selection (e.g. Op Amp). As an ideal communication system, VLC system has to be able to provides wide bandwidth access with minimum noise. The Transimpedance amplifiers (TIAs) is one of main components in optical system which is placed in the first stage of receiver system. It is used to convert the current output from photodiode to voltage. We have designed a 1 MHz fGBW TIA with low noise (in µVrms range). This paper aims to explain the design and implementation of TIA circuit with photovoltaic topology which cover empirical calculations and simulation of TIA’s bandwidth and its noise sources, i.e. resistor feedback noise, current noise, voltage noise and total noise based on RSS. The OP-AMP is chosen from Texas Instruments product, OPA 380, and photodiode is chosen from OSRAM, SFH213, then simulated by TINA simulator. The noise in TIA circuit is analyzed clearly. The developed kit is ready to be implemented in VLC system.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5737
      Issue No: Vol. 15, No. 3 (2017)
  • Weighted Least Squared Approach to Fault Detection and Isolation for GPS
           Integrity Monitoring

    • Authors: Ershen Wang, Fuxia Yang, Pingping Qu, Tao Pang, Xiaoyu Lan
      Abstract: Reliability of a global navigation satellite system is one of great importance for global navigation purposes. Therefore, an integrity monitoring system is an inseparable part of aviation navigation system. Failures or faults due to malfunctions in the systems should be detected to keep the integrity of the system intact. In order to solve the problem that least squares method detects and isolates a satellite fault for GPS integrity monitoring, in this paper, a weighted least squares algorithm is proposed for satellite fault detection and isolation. The algorithm adopts the diagonal elements of the covariance matrix of GPS measurement equation as the weighted factor. Firstly, the weighted least squares approach for satellite fault detection establishes the test statistic by the sum of the squares of the pseudo-range residuals of each satellite for GPS. Then, the detection threshold is obtained by the false alarm rate of the fault detection, probability density function and visiable satellite number.The effectiveness of the proposed approach is illustrated in a problem of GPS (Global Positioning System) autonomous integrity monitoring system. Through the real raw measured GPS data,based on least squares RAIM method and the weighted least squares RAIM approach, the performance of the two algorithms is compared. The results show that the proposed RAIM approach is superior to the least squares RAIM algorithm in the sensitivity of fault detection and fault isolation performance for GPS integrity monitoring.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5800
      Issue No: Vol. 15, No. 3 (2017)
  • An Improved Repetitive Control for Circulating Current Restraining in

    • Authors: Yahui Wang, Yijia Cao, Yong Li, Chang Li
      Abstract: The modular multilevel converter (MMC) is widely used in many important application fields such as high voltage DC transmission system. And the multi-terminal architecture of it attracts many attentions. However, the circulating current of MMC is an inherent problem which is mainly caused by the voltage mismatch between arms and DC bus. In this paper, an advanced repetitive control method is proposed. This method is based on the even-harmonic characteristic of the circulating current and the potential feature of repetitive control that it has an internal integration part. The pole diagram of the closed loop transform function of the proposed control system proves the stability of the proposed method. And according to the simulation results of a three-terminal MMC-MTDC model in PSCAD/EMTDC, the improved repetitive control presents better circulation repression ability and superior anti-interference capability by comparing with traditional PI control method. Additionally, the simulation results also indicate that the proposed repetitive controller can restrain the fluctuation of SM voltage more effectively than PI control.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5854
      Issue No: Vol. 15, No. 3 (2017)
  • Application Profiling and Mapping on NoC-based MPSoC Emulation Platform on
           Reconfigurable Logic

    • Authors: Jia Wei Tang, Yuan Wen Hau, Nasir Shaikh-Husin, Muhammad Nadzir Marsono
      Abstract: In network-on-chip (NoC) based multi-processor system-on-chip (MPSoC) development, application profiling is one of the most crucial step during design time to search and explore optimal mapping. Conventional mapping exploration methodologies analyse application-specific graphs by estimating its run-time behaviour using analytical or simulation models. However, the former does not replicate the actual application run-time performance while the latter requires significant amount of time for exploration. To map applications on a specific MPSoC platform, the application behaviour on cycle-accurate emulated platform should be considered for obtaining better mapping quality. This paper proposes an application mapping methodology that utilizes a MPSoC prototyped in Field-Programmable Gate Array (FPGA). Applications are implemented on homogeneous MPSoC cores and their costs are analysed and profiled on the platform in term of execution time, intra-core communication and inter-core communication delays. These metrics are utilized in analytical evaluation of the application mapping. The proposed analytical-based mapping is demonstrated against the exhaustive brute force method. Results show that the proposed method is able to produce quality mappings compared to the ground truth solutions but in shorter evaluation time.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6513
      Issue No: Vol. 15, No. 3 (2017)
  • The Performance of an Integrated Transformer in a DC/DC Converter

    • Authors: Abdelhadi Namoune, Azzedine Hamid, Rachid Taleb
      Abstract: The separation between the low-voltage part and high-voltage part of the converter is formed by a transformer that transfers power while jamming the DC ring. The resonant mode power oscillator is utilized to allow elevated competence power transfer. The on-chip transformer is probable to have elevated value inductance, elevated quality factors and elevated coupling coefficient to decrease the loss in the oscillation. The performance of a transformer is extremely dependent on the structure, topology and other essential structures that create it compatible with the integrated circuits IC process such as patterned ground shield (PGS). Different types of transformers are modeled and simulated in MATLAB; the performances are compared to select the optimum design. The on-chip transformer model is simulated and the Results of MATLAB simulation are exposed, showing an excellent agreement in radio frequency RF.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.4251
      Issue No: Vol. 15, No. 3 (2017)
  • Packet Loss Rate Differentiation in slotted Optical Packet Switching

    • Authors: Omar Najah, Kamaruzzaman Seman, Khairi Abdulrahim
      Abstract: We propose a multi-class mechanism for Optical Code Division Multiplexing (OCDM), Wavelength Division Multiplexing (WDM) Optical Packet Switch (OPS) architecture capable of supporting Quality of Service (QoS) transmission. OCDM/WDM has been proposed as a competitive hybrid switching technology to support the next generation optical Internet. This paper addresses performance issues in the slotted OPS networks and proposed four differentiation schemes to support Quality of Service. In addition, we present a comparison between the proposed schemes as well as, a simulation scheduler design which can be suitable for the core switch node in OPS networks. Using software simulations the performance of our algorithm in terms of losing probability, the packet delay, and scalability is evaluated.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5019
      Issue No: Vol. 15, No. 3 (2017)
  • 94 GHz Millimeter Wave Conducted Speech Enhancement

    • Authors: Sheng Li, Fuming Chen, Jinyan Hu, Hongbo Li, Lijun Qiu, Ying Tian, Jianqi Wang
      Abstract: The traditional microphone speech acquisition method has several limitations, such as short acquisition distance, non-directivity, weak ability to compensate for anti-acoustic noise, and poor sensitivity. As an alternative, our lab developed a new type of speech detection system using bio-radar. This novel speech detection method may effectively compensate for the shortcomings of the traditional microphone because of the special features of bio-radar. However, the detected radar speech is also corrupted by specific electromagnetic and ambient noises. Therefore, this study proposes a minimum mean-square error (MMSE) short-time spectral amplitude estimate algorithm to enhance radar captured speech. Because the proposed approach employs an optimal spectral amplitude estimator as well as a method to minimize the mean-square error of the log-spectra in enhancing noisy speech, this algorithm significantly reduces the colored residual noise. The enhanced radar speech was evaluated by both subjective and objective quality evaluation methods. The results demonstrate that the bio-radar can successfully detect speech signal and the proposed speech enhancement algorithm can improve radar captured speech quality.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5166
      Issue No: Vol. 15, No. 3 (2017)
  • Design of Circular Patch With Double C-Shaped Slot Microstrip Antenna for
           LTE 1800 MHz

    • Authors: Yusnita Rahayu, Jherino Permana Putra
      Abstract: The design of a circular patch microstrip antenna with double C-shaped for LTE 1800 MHz is presented. The antenna is designed using FR-4 with dielectric constant of ε = 4.3, with thickness of substrate that is 1.6 mm and the thickness of patch and ground are 0.025 mm, Respectively the simulation results presented that the antenna works at frequency of 1714-1889.6 MHz, and work very well at frequency of 1800 MHz with a Return loss -20.484 dB, bandwidth 175.6 MHz.  Technique used for broaden the bandwidth  by using double C-shaped slot. In this paper presents S-Parameters, and Gain of microstrip antenna circular patch with double C-shaped slot.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5492
      Issue No: Vol. 15, No. 3 (2017)
  • Design LTE Microstrip Antenna Rectangular Patch with Beetle-Shaped Slot

    • Authors: Yusnita Rahayu, Haziq Hazman, Razali Ngah
      Abstract: In this paper, the microstrip antenna rectangular patch with beetle shaped slot is presented. The characterization results of the proposed antenna obtained by changing the dimensions of the ground plane. CST software is used to design and analyze this proposed antenna. The simulated results of proposed antenna show that the antenna works at the frequency of 2.1 GHz while the return loss of -32.18 dB with the bandwidth reaches 155.19 MHz and the gain of 3.895 dBi.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5493
      Issue No: Vol. 15, No. 3 (2017)
  • Wireless Body Area Networks for Healthcare Applications: An Overview

    • Authors: Muhammad Anwar, Abdul Hanan Abdullah, Kashif Naseer Qureshi, Abdul Hakeem Majid
      Abstract: Healthcare systems have been facing various new challenges due to increasing and rising aging population in healthcare. Advance information and communication technologies have introduced Wireless Body Area Networks (WBANs) for healthcare systems. WBANs provide different monitoring services in healthcare sector for monitoring their patients with more convenience. WBANs are economical solutions and non-invasive technology for healthcare applications. This review paper provides a comprehensive review on WBANs applications, services and recent challenges.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5793
      Issue No: Vol. 15, No. 3 (2017)
  • Malicious User Attack in Cognitive Radio Networks

    • Authors: N. Armi, S. Rizvi, W.Z. Khan, H. Zangoti, W. Gharibi, C. Wael
      Abstract: Signal detection in cognitive radio network (CRN) is influenced by several factors. One of them is malicious user that emulate primary user (PU) signal. Emulation of PU signal causes detection error. This paper investigates the impact of malicious user attack to PU signal detection. A number of malicious users are randomly deployed around secondary user (SU) at a certain distance. They attempt to attack primary signal detection that is transmitted from 100 km to SU receiver. Then, the received signal power at secondary receiver and the performance of probability of false alarm and probability of miss detection under two hypothesis of Neyman Pearson criterion are studied. The derived results show that a number of malicious users has a significant impact to the performance of received power at SU and detection error rate.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5794
      Issue No: Vol. 15, No. 3 (2017)
  • Bandwidth and Gain Enhancement of MIMO Antenna by using Ring and Circular
           Parasitic with Air-Gap Microstrip Structure

    • Authors: Teguh Firmansyah, Herudin Herudin, Suhendar Suhendar, Romi Wiryadinata, M Iman Santoso, Yus Rama Denny, Toto Supriyanto
      Abstract: This research was proposed a circular patch MIMO antenna by using a ring and circular parasitic radiator structure. As a novelty, in order to enhance bandwidth and gain of circular patch MIMO antenna, a conventional circular patch MIMO antenna will be added a ring and a circular parasitic. Therefore, this research was investigated a conventional MIMO antenna (C-MA), ring parasitic MIMO antenna (RP-MA), and circular parasitic MIMO antenna (CP-MA) as Model 1, Model 2, and Model 3, respectively. This MIMO antenna was designed on FR4 microstrip substrate with er= 4.4, thickness h=1.6 mm, and tan d= 0.0265. This MIMO antenna has center frequency 2.35 GHz which is a frequency band for LTE application in Indonesia. An Advance Design System (ADS) software was used to determine the antenna parameters. The MIMO antenna C-MA / RP-MA/ CP-MA achieves 2.36GHz/ 2.38GHz/ 2.38 GHz, 70 MHz/ 100 MHz/ 120 MHz, 1.625 dBi/ 4.066 dBi/ 4.117 dBi, 6.414 dBi/ 7.26 dBi/ 7.153 dBi, 33.9 %/ 47.8 %/ 49.70 %, -12.35 dB/ -22.21 dB/ -23.66 dB, and -30.924 dB/ -28.46 dB/ -27.59 dB for center frequency, bandwidth, gain, directivity, efficiency, reflection coefficient, and mutual coupling, respectively. Compared to C-MA (Model1) performances, The result showed that proposed antenna has wider-bandwidth/ higher-gain with 42.8%/ 150.2 %, and 71.4%/ 163.3% for RP-MA (Model 2) and CP-MA (Model 3), respectively. The proposed antenna has size of 50 mm x 130 mm x 23.2 mm. Measured results are in a good agreement with the simulated results.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6377
      Issue No: Vol. 15, No. 3 (2017)
  • Wave Peak and Dispersion in Transmission of Bragg Grating Coupler

    • Authors: Romi Fadli Syahputra, Toto Saktioto, Ros Meri, Okfalisa Okfalisa, Syamsudhuha Syamsudhuha
      Abstract: This paper describes a numerical experiment of design and operation of a fiber coupler between single mode fiber and fiber Bragg grating (FBG). A characterization of fiber coupler is simulated by varying long grating of 10mm to 60mm using transfer matrix method based on coupled mode equation. The wave peak, transmission, and dispersion parameters are analyzed to determine the performance of the fiber coupler. The transmission spectrum showed the wave peaks rise to any increase in the grating length on channel 1 and channel 2. Transmission on channel 1 and channel 2 decreased from the  wavelength range of 1.45 µm – 1.55 µm and rised in the range of 1,55 µm – 1,65 µm for each increment in length of grating. The dispersion showed the zero dispersion at specific wavelength for each increase in length of grating.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6383
      Issue No: Vol. 15, No. 3 (2017)
  • Planar Microwave Sensors for Accurate Measurement of Material
           Characterization: A Review

    • Authors: Norhanani Abd Rahman, Zahriladha Zakaria, Rosemizi Abd Rahim, Yosza Dasril, Amyrul Azuan Mohd Bahar
      Abstract: Microwave sensor is used in various industrial applications and requires highly accurate measurements for material properties. Conventionally, cavity waveguide perturbation, free-space transmission, open-ended coaxial probe, and planar transmission line technique have been used for characterizing materials. However, these planar transmission lines are often large and expensive to build, further restricting their use in many important applications. Thus, this technique is cost effective, easy to manufacture and due to its compact size, it has the potential to produce sensitivity and a high Q-factor for various materials. This paper reviews the common characteristics of planar transmission line and discusses numerous studies about several designs of the microstrip resonator to improve the sensor performance in terms of the sensitivity and accuracy. This technique enables its use for several industrial applications such as agriculture and quality control. It is believed that previous studies would lead to a promising solution of characterizing materials with high sensitivity, particularly in determining a high Q-factor resonator sensor.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6684
      Issue No: Vol. 15, No. 3 (2017)
  • Miniaturized Minkowski-Island Fractal Microstrip Antenna Fed by Proximity
           Coupling for Wireless Fidelity Application

    • Authors: I Putu Elba Duta Nugraha, Indra Surjati, Syah Alam
      Abstract: This paper proposed a new design of Minkowski Island microstrip antenna fed by proximity coupling with partial ground plane. The design are consists of two layers of substrate, on the top substrate is the antenna patch and on the bottom substrate is the proximity feed line and the partial ground. Using the Minkowski Island fractal technique, the dimension of the patch can be reduced up to 58.7%. While the proximity feed line in this design are used to increase the impedance bandwidth and from the measurement the impedance bandwidth of the proposed antenna is 240 MHz with return loss of -24.54 dB and VSWR of 1.126.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6826
      Issue No: Vol. 15, No. 3 (2017)
  • A Mathematical Approach for Hidden Node Problem in Cognitive Radio

    • Authors: Felix Obite, Kamaludin Yusof, Jafri Din
      Abstract: Cognitive radio (CR) technology has emerged as a realistic solution to the spectrum scarcity problem in present day wireless networks. A major challenge in CR radio networks is the hidden node problem, which is the inability of the CR nodes to detect the primary user. This paper proposes energy detector-based distributed sequential cooperative spectrum sensing over Nakagami-m fading, as a tool to solve the hidden node problem. The derivation of energy detection performance over Nakagami-m fading channel is presented. Since the observation represents a random variable, likelihood ratio test (LRT) is known to be optimal in this type of detection problem. The LRT is implemented using the Neyman-Pearson Criterion (maximizing the probability of detection but at a constraint of false alarm probability). The performance of the proposed method has been evaluated both by numerical analysis and simulations. The effect of cooperation among a group of CR nodes and system parameters such as SNR, detection threshold and number of samples per CR nodes is investigated. Results show improved detection performance by implementing the proposed model.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6897
      Issue No: Vol. 15, No. 3 (2017)
  • Design and Improvement of a Compact Bandpass Filter using DGS Technique
           for WLAN and WiMAX Applications

    • Authors: Ahmed Boutejdar, Mohamed Amzi, Saad Dosse Bennani
      Abstract: In this article, A compact size band pass filter based on octagonal resonators is presented to give sharp response at desired frequency bands along with very low insertion loss. The proposed filter structure is composed of octagonal microstrip resonators, backed by Quasi-Yagi slots ‘Quasi-Yagi Defected Ground Structure’ (Quasi-Yagi-DGS). By controlling the electrical coupling between the octagonal–strip and the Quasi-Yagi-DGS, the bandpass filter’s stopband is optimized for better rejection. The proposed BPF has low insertion loss and compact size because of the slow-wave effect. Meanwhile, sharp rejection bands induced by the presence of two transmission zeros. The simulated center frequency and passband insertion loss are 2.4 GHz and 0.6 dB, respectively.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6917
      Issue No: Vol. 15, No. 3 (2017)
  • Synchronization Control of Complex Dynamical Networks Based on Uncertain

    • Authors: Qianqian Jia
      Abstract: In recent years, the study of complex networks has been a focus subject of technology fields.  In this paper, we consider the adaptive control and synchronization of uncertain complex networks. By using the adaptive control techniques with the linear feedback updated law and the well-known  invariant principle on dynamical system theory, some simple yet generic criteria are derived.  Furthermore, the result is applied to typical chaotic cellular neural networks (CNN). Finally, numerical simulations are presented to demonstrate the feasibility and effectiveness of the proposed techniques.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.4224
      Issue No: Vol. 15, No. 3 (2017)
  • Integral Backstepping Approach for Mobile Robot Control

    • Authors: Kamel Bouzgou, Benaoumeur Ibari, Laredj Benchikh, Zoubir Ahmed-Foitih
      Abstract: This paper presents the trajectory tracking problem of a unicycle-type mobile robots. A robust output tracking controller for nonlinear systems in the presence of disturbances is proposed, the approach is based on the combination of integral action and Backstepping technique to compensate for the dynamic disturbances. For desired trajectory, the values of the linear and angular velocities of the robot are assured by the kinematic controller. The control law guarantees stability of the robot by using the lyapunov theorem. The simulation and experimental results are presented to verify the designed trajectory tracking control.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5667
      Issue No: Vol. 15, No. 3 (2017)
  • Development of Ammonia Gas Leak Detection and Location Method

    • Authors: Ding Xibo, Wang Ru-yue
      Abstract: This paper proposed the gas for industrial ammonia leak diffusion model and the Gauss method of leakage localization. A set of wireless ammonia leak alarm system is composed of sensor node, network coordinator and host used in the industrial field was developed, the purpose is to reduce the loss of property caused by the leakage of ammonia industry. Using the monitoring system to carry out the ammonia leak location simulation measurement experiment, the result shows that the relative positioning error of the monitoring system is about 12%, which meets the needs of industrial production safety monitoring. Using the wireless sensor network to monitor the concentration of ammonia gas and locate the leakage source, it solves the problems of traditional wired alarm system, such as difficult wiring and weak expansibility, which helps to find the leak timely and provides a reference for the emergency rescue work. 
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5079
      Issue No: Vol. 15, No. 3 (2017)
  • Estimation of Optimum Number of Poles for Random Signal by Yule-Walker

    • Authors: Ahmed Al Amin, Md. Shoriful Islam, K.M. Abdul Al Woadud, Md. Jahirul Islam, Md. Imrul Kayes
      Abstract: The Yule-Walker method is an effective method to estimate the system response or spectrum for random signal. Hence most of the noise and spurious signals are random in nature, so it is very convenient to estimate their spectrum by Yule-Walker method successfully. The Yule-Walker method is an autoregressive process to estimate the poles and errors also based on the number of poles for Wide Sense Stationary (WSS) process as well. Moreover the value of zero will be correspondingly calculated based on the poles in case of all poles model. The main concern of this paper is to analyze the Yule-Walker method and estimate the poles and zero along with the error based on the number of poles for a random signal. Moreover analyze the results to find out the optimum number of poles for least possible error.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6103
      Issue No: Vol. 15, No. 3 (2017)
  • A Review on Methods of Identifying and Counting Aedes Aegypti Larvae using
           Image Segmentation Technique

    • Authors: Mohamad Aqil Mohd Fuad, Mohd Ruddin Ab Ghani, Rozaimi Ghazali, Mohamad Fani Sulaima, Mohd Hafiz Jali, Tole Sutikno, Tarmizi Ahmad Izzuddin, Zanariah Jano
      Abstract: Aedes aegypti mosquitoes is a small slender fly insect that spreads the arbovirus from flavivirus vector through its sucking blood. An early detection of this species is very important because once these species turn into adult mosquitoes a population control becomes more complicated. Things become worse when difficult access places like water storage tank becomes one of the breeding favorite places for Aedes aegypti mosquitoes. Therefore, there is a need to help the field operator during the routine inspection for an automated identification and detection of Aedes aegypti larvae, especially at difficult access places. This paper reviews different methodologies that have been used by various researchers in identifying and counting Aedes aegypti. The objective of the review was to analyze the techniques and methods in identifying and counting the Aedes Aegypti larvae of various fields of study from 2008 and above by taking account their performance and accuracy. From the review, thresholding method was the most widely used with high accuracy in image segmentation followed by hidden Markov model, histogram correction and morphology operation region growing.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6422
      Issue No: Vol. 15, No. 3 (2017)
  • Feature Extraction of Musical Instrument Tones using FFT and Segment

    • Authors: Linggo Sumarno, I. Iswanjono
      Abstract: A feature extraction for musical instrument tones that based on a transform domain approach was proposed in this paper. The aim of the proposed feature extraction was to get the lower feature extraction coefficients. In general, the proposed feature extraction was carried out as follow. Firstly, the input signal was transformed using FFT (Fast Fourier Transform). Secondly, the left half of the transformed signal was divided into a number of segments. Finally, the averaging results of that segments, was the feature extraction of the input signal. Based on the test results, the proposed feature extraction was highly efficient for the tones, which have many significant local peaks in the Fourier transform domain, because it only required at least four feature extraction coefficients, in order to represent every tone.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.3381
      Issue No: Vol. 15, No. 3 (2017)
  • Decision Support System for Bats Identification using Random Forest and

    • Authors: Deden Sumirat Hidayat, Imas Sukaesih Sitanggang, Gono Semiadi
      Abstract: Morphometric and morphological bat identification is a conventional method of identification and requires precision, significant experience, and encyclopedic knowledge.  Morphological features of a species may sometimes similar to that of another species and this causes several problem for the beginners working with bat’s taxonomy.  The purpose of the study was to implement and conduct the random forest and C5.0 algorithm analysis in order to decide characteristics and carry out identification of bat species. It also aims at developing supporting decision-making system based on the model to find out the characteristics and identification of the bat species. The study showed that C5.0 algorithm prevailed and was selected with the mean score of accuracy of 98.98, while the mean score of accuracy for the random forest was 97.26. Total rules to be implemented in the DSS to identify species with morphometric and morphological attributes and rare species were 50 rules.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.3638
      Issue No: Vol. 15, No. 3 (2017)
  • Predicting the Presence of Learning Motivation in Electronic Learning: a
           New Rules to Predict

    • Authors: Christina Juliane, Arry A. Arman, Husni S. Sastramihardja, Iping Supriana
      Abstract: Research affirms that electronic learning (e-learning) has a great deal of advantages to learning process, it’s provides learners with flexibility in terms of time, place, and pace. That easiness was not be a guarantee of a good learning outcomes though they got the same learning material and course, because the fact is the outcomes was not the same from one to another and even not satisfy enough. One of prerequisite to the successful of e-learning process is the presence of learning motivation and it was not easy to identify. We propose a novel model to predicting the presence of learning motivation in e-learning using those attributes that have been identified in previous research. This model has been built using WEKA toolkit by comparing fourteen algorithms for Tree Classifier and ten-fold cross validation testing methods to process 3.200 of data sets. The best accuracy reached at 91.1% and identified four parameters to predict the presence of learning motivation in e-learning, and aim to assist teachers in identify whether student needs motivation or does not. This study also confirmed that Tree Classifier still has the best accuracy to predict and classify academic performance, it was reached average 90.48% for fourteen algorithm for accuracy value.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.4286
      Issue No: Vol. 15, No. 3 (2017)
  • A Crop Pests Image Classification Algorithm Based on Deep Convolutional
           Neural Network

    • Authors: RuJing Wang, Jie Zhang, Wei Dong, Jian Yu, ChengJun Xie, Rui Li, TianJiao Chen, HongBo Chen
      Abstract: Conventional pests image classification methods may not be accurate due to the complex farmland background, sunlight and pest gestures. To raise the accuracy, the deep convolutional neural network (DCNN), a concept from Deep Learning, was used in this study to classify crop pests image. On the ground of our experiments, in which LeNet-5 and AlexNet were used to classify pests image, we have analyzed the effects of both convolution kernel and the number of layers on the network, and redesigned the structure of convolutional neural network for crop pests. Further more, 82 common pest types have been classified, with the accuracy reaching 91%. The comparison to conventional classification methods proves that our method is not only feasible but preeminent
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5382
      Issue No: Vol. 15, No. 3 (2017)
  • Improving Posture Accuracy of Non-holonomic Mobile Robot System with
           Variable Universe of Discourse

    • Authors: Siti Nurmaini, Bambang Tutuko, Kemala Dewi, Velia Yuliza, Tresna Dewi
      Abstract: This paper presents a method to decrease imprecision and inaccuracy that have the tendency to influence the posture of non-holonomic mobile by using the adaptive tuning of universe of discourse. As such, the primary objective of the study is to force the posture error of x(t), y(t) and θ(t) towards zero. Hence, for each step of tuning the fuzzy domain, about 20% of imprecision and inaccuracy had been added automatically into the variable universe fuzzy, while the control input was bound via scaling gain. Furthermore, the experimental results showed that the tuning of universe fuzzy parameters could increase the performance of the system from the aspects of response time and error for steady state through better control of inaccuracy. Besides, the domains of universe fuzzy input [-4,4] and output [0,6] exhibited good performance in inching towards zero values as the steady state error was about 1% for x(t) position, 0.02% for y(t) position, and 0.16% for θ(t) orientation, whereas the posture error in the given reference was about 0.0002% .
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6078
      Issue No: Vol. 15, No. 3 (2017)
  • Improving DNA Barcode-based Fish Identification System on Imbalanced Data
           using SMOTE

    • Authors: Wisnu Ananta Kusuma, Nurdevi Noviana, Lailan Sahrina Hasibuan, Mala Nurilmala
      Abstract: Problem in imbalanced data is very common in classification or identification. The problem is raised when the number of instances of one class far exceeds the other. In the previous research, our DNA barcode-based Identification System of Tuna and Mackerel was developed in imbalanced dataset. The number of samples of Tuna and Mackerel were much more than the number of other fish samples. Therefore, the accuracy of the classification model was probably still in bias. This research aimed at to employ Synthetic Minority Oversampling Technique (SMOTE) to yield balanced dataset. We used k-mers frequencies from DNA barcode sequence as features and Support Vector Machine (SVM) as classification method. In this research we used trinuclotide (3-mers) and tetranucleotide (4-mers). The training dataset was taken from Barcode of Life Database (BOLD). For evaluating the model, we compared the accuracy of model using SMOTE and without SMOTE in order to classify DNA barcode sequences taken from Department of Aquatic Product Technology, Bogor Agricultural University. The results showed that the accuracy of the model in the species level using SMOTE was 7% and 13% higher than those of non-SMOTE for trinucleotide (3-mers) and tetranucleotide (4-mers), respectively. It is expected that the use of SMOTE, as one of data balancing technique, could increase the accuracy of DNA barcode based fish classification system, particularly in the species level which is difficult to be identified.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5011
      Issue No: Vol. 15, No. 3 (2017)
  • Foreign Tourist Arrivals Forecasting Using Recurrent Neural Network
           Backpropagation Through Time

    • Authors: Wayan Oger Vihikan, I Ketut Gede Darma Putra, I Putu Arya Dharmaadi
      Abstract: Bali as an icon of tourism in Indonesia has been visited by many foreign tourists. Thus, Bali is one of the provinces that contribute huge foreign exchange for Indonesia. However, this potential could be threatened by the effectuation of the ASEAN Economic Community as it causes stricter competition among ASEAN countries including in tourism field. To resolve this issue, Balinese government need to forecast the arrival of foreign tourist to Bali in order to help them strategizing tourism plan. However, they do not have an appropriate method to do this. To overcome this problem, this study contributed a forecasting method using Recurrent Neural Network Backpropagation Through Time. We also compare this method with Single Moving Average method. The results showed that proposed method outperformed Single Moving Average in 10 countries tested with 80%, 70%, and 70% better MSE results for 1, 3 and 6 months ahead forecast respectively.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5993
      Issue No: Vol. 15, No. 3 (2017)
  • HABCO : A Robust Agent on Hybrid Ant-Bee Colony Optimization

    • Authors: Abba Suganda Girsang, Chun-Wei Tsai, Chu-Sing Yang
      Abstract: The purpose of this research is to generate a robust agent by combining bee colony optimization (BCO) and ELU-Ants for solving traveling salesman problem (TSP), called HABCO. The robust agents, called ant-bees, firstly are grouped into three types scout, follower, recruiter at each stages. Then, the bad agents are high probably discarded, while the good agents are high probably duplicated in earlier steps. This first two steps mimic BCO algorithm. However, constructing tours such as choosing nodes, and updating pheromone are built by ELU-Ants method.To evaluate the performance of the proposed algorithm, HABCO is performed on several benchmark datasets and compared to ACS and BCO. The experimental results show that HABCO achieves the better solution, either with or without 2opt.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.3656
      Issue No: Vol. 15, No. 3 (2017)
  • Regression Modelling for Precipitation Prediction Using Genetic Algorithms

    • Authors: Asyrofa Rahmi, Wayan Firdaus Mahmudy
      Abstract: This paper discusses the formation of an appropriate regression models in precipitation prediction. Precipitation prediction has a major influence to multiply the agricultural production of potatoes for some farmers in Tengger, East Java, Indonesia. Periodically, the precipitation has non-linear patterns. By using a non-linear approach, problems in prediction of precipitation shows the results closer. Genetic algorithm functioning choose precipitation period which which form the best model. To prevent early convergence, testing the best combination value of crossover rate and mutation rate. Based on the RMSE value of each methods on every locations, prediction using GA-Non Linear Regression is better than Fuzzy Tsukamoto for each locations. Compared to GSTAR-SUR, precipitation prediction using GA is better. This has been proved that for 3 locations GA is superior and on 1 location, GA has least value of deviation level.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.4028
      Issue No: Vol. 15, No. 3 (2017)
  • Twitter’s Sentiment Analysis on Gsm Services using Multinomial
           Naïve Bayes

    • Authors: Aisah Rini Susanti, Taufik Djatna, Wisnu Ananta Kusuma
      Abstract: Telecommunication users are rapidly growing each year. As people keep demanding a better service level of Short Message Service (SMS), telephone or data use, service providers compete to attract their customer, while customer feedbacks in some platforms, for example Twitter, are their souce of information. Multinomial Naïve Bayes Tree, adapted from the method of Multinomial Naïve Bayes and Decision Tree, is one technique in data mining used to classify the raw data or feedback from customers.Multinomial Naïve Bayes method used specifically addressing frequency in the text of the sentence or document. Documents used in this study are comments of Twitter users on the GSM telecommunications provider in Indonesia.This research employed Multinomial Naïve Bayes Tree classification technique to categorize customers sentiment opinion towards telecommunication providers in Indonesia. Sentiment analysis only included the class of positive, negative and neutral. This research generated a Decision Tree roots in the feature "aktif" in which the probability of the feature "aktif" was from positive class in Multinomial Naive Bayes method.The evaluation showed that the highest accuracy of classification using Multinomial Naïve Bayes Tree (MNBTree) method was 16.26% using 145 features. Moreover, the Multinomial Naïve Bayes (MNB) yielded the highest accuracy of 73,15% by using all dataset of 1665 features. The expected benefits in this research is that the Indonesian telecommunications provider can evaluate the performance and services to reach customer satisfaction of various needs.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.4284
      Issue No: Vol. 15, No. 3 (2017)
  • Step-Function Approach for E-Learning Personalization

    • Authors: Sfenrianto Sfenrianto, Zainal A. Hasibuan
      Abstract: Personalization is an alternative to improve the learning process for an e-Learning environment. It is a useful strategy to adjust the student' needs based on their characteristics to make learning more effectively. In this study, we propose the step-function approach for personalization in e-learning. It provides the students with adopting the knowledge-ability factor (Novice, Average, or Good category) that matches with their learning materials levels (Level1, Level2, or Level3). The approach implemented into an e-learning which called SCELE-PDE and used as the experimental group in two stages with different scenarios. In the first, without a step-function approach, but the SCELE-PDE can identify an initial of student's ability to knowledge category. The second stage has used the approach to providing students with personalization in e-Learning to adapt learning material based on a knowledge category. As a result, is the step-function approach has successfully to improve the student performance in the learning process during the course. Thus, by using such step-function approach, we recommend for enhancing e-Learning personalized with the approach.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.4457
      Issue No: Vol. 15, No. 3 (2017)
  • The Addition Symptoms Parameter on Sentiment Analysis to Measure Public
           Health Concerns

    • Authors: Yohanssen Pratama, Puspoko Ponco Ratno
      Abstract: Information about public health has a very important role not only for health practitioners, but also for goverment. The importance of health information can also affect the emotional changes that occur in the community, especially if there is news about the spread of infectious disease (epidemic) in particular area at the time, such as case of outbreaks Ebola disease or Mers in specific area. Based on data obtained from Semiocast, Indonesia is the country with fifth largest number of Twitter users in the world, where every topic that lively discussed will also influence a global trending topic. This paper will discuss the measurement of public health concern (Degree of Concern) level by using sentiment analysis classification on the twitter status. Sentiment data of the tweets were analyzed and given some value by using a scoring method. The scoring method equation (Kumar A. et al., 2012) will be tested with new additional parameters, ie symptoms parameters. The value of any twitter user sentiment is determined based on adjectives, verbs, and adverbs that contained in the sentence. The method that we used to find the semantic value of adjectives is corpus-based method. While for finding the semantic value of the verb and adverb we used a dictionary-based method.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.4711
      Issue No: Vol. 15, No. 3 (2017)
  • A Novel Space–time Discontinuous Galerkin Method for Solving of
           One-dimensional Electromagnetic Wave Propagations

    • Authors: Pranowo Pranowo
      Abstract: In this paper we propose  a high-order space-time discontinuous Galerkin (STDG) method  for solving of one-dimensional electromagnetic wave propagations in homogeneous medium. The STDG method uses finite elements discretizations in spatial and temporal domain simultaneously with high order piecewise Jacobi polynomial as the basis functions. The algebraic equations are solved using Block Gauss-Seidel iteratively in each time step. The STDG method is unconditionally stable, so the CFL number can be chosen arbitrarily. Numerical examples show that the proposed STDG method is of exponentially accuracy in time.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5080
      Issue No: Vol. 15, No. 3 (2017)
  • Binarization of Ancient Document Images Based on Multipeak Histogram

    • Authors: Fitri Arnia, Khairul Munadi
      Abstract: In document binarization, text is segmented from the background. This is an important step, since the binarization outcome determines the success rate of the optical character recognition (OCR). In ancient documents, that are commonly noisy, binarization becomes more difficult. The noise can reduce binarization performance, and thus the OCR rate. This paper proposes a new binarization approach based on an assumption that the histograms of noisy documents consist of multipeaks. The proposed method comprises three steps: histogram calculation, histogram smoothing, and the use of the histogram to track the first valley and determine the binarization threshold. In our simulations we used a set of Jawi ancient document images with natural noises. This set is composed of 24 document tiles containing two noise types: show-through and uneven background. To measure performance, we designed and implemented a point compilation scheme. On average, the proposed method performed better than the Otsu method, with the total point score obtained by the former being 7.5 and that of the latter 4.5. Our results show that as long as the histogram fulfills the multipeak assumption, the proposed method can perform satisfactorily. 
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5105
      Issue No: Vol. 15, No. 3 (2017)
  • Manager Perceptions towards the Success of E-Performance Reporting System

    • Authors: A'ang Subiyakto, Ditha Septiandani, Evy Nurmiati, Yusuf Durachman, Abd. Rahman Ahlan, Mira Kartiwi
      Abstract: Managers are one of the key informants in the information system (IS) success measurements. In fact, besides the determinant agents are rarely involved in the assessments, most of the measurements are also often performed by the technical stakeholders of the systems. Therefore, the results may questionable. This study was carried to explain the factors that influence the success of an e-performance reporting system in an Indonesian university by involving ± 70% of the managers (n=66) in the sampled institution. The DeLone and McLean model was adopted and adapted here following the suggestions of the previous meta-analysis studies. The collected data was analysed using the partial least squares-structural equation modelling (PLS-SEM) for examining the four hypotheses. Despite the findings revealed acceptances of the overall hypotheses, the weak explanation of the user satisfaction variable towards the net benefit one had been the highlighted point of the study. Besides limitations of the study, the above-mentioned point may also be the practical and theoretical considerations for the next studies, especially for the IS success studies in Indonesia.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5133
      Issue No: Vol. 15, No. 3 (2017)
  • The Pessimistic Investor Sentiments Indicator in Social Networks

    • Authors: Rui Jin, Hong-Li Zhang, Xing Wang, Xiao-Meng Wang
      Abstract: With the worldwide proliferation of social networks, the social networks have played an important role in the social activities .Peoples are inclined to obtain the corresponding public opinion to make decision such as shopping, education, investment and so on. Analysis of data generated by social networks has become an important field of research, however in the field of public opinion analysis of social networks the quantitative measure indexes are still lacking. In this paper, the calculation method of pessimistic investor sentiments indicator is proposed, and the index has a certain theoretical and practical value.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5360
      Issue No: Vol. 15, No. 3 (2017)
  • Histogram Equalization for Improving Quality of Low-Resolution
           Ultrasonography Images

    • Authors: Retno Supriyanti, Subkhi Adhi Priyono, Eko Murdyantoro, Haris Budi Widodo
      Abstract: The current development of digital image processing techniques have been very rapid. Application of digital image processing both hardware and software are available with a variety of features as a form of superiority. Medical ultrasonography is one of the results of digital image processing technology.  It is a kind of  diagnostic imaging technique with ultrasonic that is used to produce images of internal organs and muscles, size, structure, and wound pathology, which makes this technique is useful for checking organ. However the images produced by low resolution ultrasonography device is not fully produce clear information. In this research we use histogram equalization to improve image quality. In this paper we emphasize on the comparison of the two methods in the histogram equalization, namely Enhance Contrast Using Histogram Equalization (ECHE) and Contrast-Limited Adaptive Histogram Equalization (CLAHE). The results showed that CLAHE give the best results, with the parameter value Nbins 256 and Distribution Rayleigh with MSE value 9744.80 and PSNR value 8.284150.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5537
      Issue No: Vol. 15, No. 3 (2017)
  • Social Media Success Model for Knowledge Sharing (Scale Development and

    • Authors: Setiawan Assegaff, H Hendri, Akwan Sunoto, Herti Yani, Desy Kisbiyanti
      Abstract: This study aimed to evaluate the success of social media as a means of sharing knowledge among scholars in Indonesia. By using Information System Success Model (DeLone and McLean), this study develops a research model that will be used to investigate what factors are contributing to the success of social media as tool for sharing knowledge among academics. This article would focus on the discussion of instrument development and validation process. The method for development and validation the research instrument was refers to the framework proposed by McKanzie et al. This study resulted in a validated instrument, the instrument could use by researchers who are interested in study social media success for knowledge sharing.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5569
      Issue No: Vol. 15, No. 3 (2017)
  • A Soft Set-based Co-occurrence for Clustering Web User Transactions

    • Authors: Edi Sutoyo, Iwan Tri Riyadi Yanto, Rd Rohmat Saedudin, Tutut Herawan
      Abstract: Web transaction clustering of webpages is important yet a challenging web mining problem. This is due to uncertainty to form clusters. Rough set theory has been utilized for clustering web user transactions, while managing uncertainty in clustering process. However, it suffers from high computational complexity and low cluster purity. In this paper, we propose a soft set approach for clustering web user transactions. Unlike rough set approach that uses similarity approach, the novelty of this approach uses a co-occurrence approach of soft set. We compare the proposed approach and rough set approaches on computational complexity and cluster purity. The results show that the proposed soft set approach achieves lower computational complexity with the improvement of more than 100% and higher cluster purity as compared to rough set-based approaches.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6382
      Issue No: Vol. 15, No. 3 (2017)
  • Using SVD and DWT Based Steganography to Enhance the Security of
           Watermarked Fingerprint Images

    • Authors: Mandy Douglas, Karen Bailey, Mark Leeney, Kevin Curran
      Abstract: Watermarking is the process of embedding information into a carrier file for the protection of ownership/copyright of digital media, whilst steganography is the art of hiding information.  This paper presents, a hybrid steganographic watermarking algorithm based on Discrete Wavelet Transform (DWT) and Singular Value Decomposition (SVD) transforms in order to enhance the security of digital fingerprint images.  A facial watermark is embedded into fingerprint image using a method of singular value replacement.  First, the DWT is used to decompose the fingerprint image from the spatial domain to the frequency domain and then the facial watermark is embedded in singular values (SV’s) obtained by application of SVD.  In addition, the original fingerprint image is not required to extract the watermark. Experimental results provided demonstrate the methods robustness to image degradation and common signal processing attacks, such as histogram and filtering, noise addition, JPEG and JPEG2000 compression with various levels of quality.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.6437
      Issue No: Vol. 15, No. 3 (2017)
  • Brown’s Weighted Exponential Moving Average Implementation in Forex

    • Authors: Seng Hansun, Subanar Subanar
      Abstract: In 2016, a time series forecasting technique which combined the weighting factor calculation formula found in weighted moving average with Brown’s double exponential smoothing procedures had been introduced. The technique is known as Brown’s weighted exponential moving average (B-WEMA), as a new variant of double exponential smoothing method which does the exponential filter processes twice. In this research, we will try to implement the new method to forecast some foreign exchange, or known as forex data, including EUR/USD, AUD/USD, GBP/USD, USD/JPY, and EUR/JPY data. The time series data forecasting results using B-WEMA then be compared with other conventional and hybrid moving average methods, such as weighted moving average (WMA), exponential moving average (EMA), and Brown’s double exponential smoothing (B-DES). The comparison results show that B-WEMA has a better accuracy level than other forecasting methods used in this research.
      PubDate: 2017-09-01
      DOI: 10.12928/telkomnika.v15i3.5410
      Issue No: Vol. 15, No. 3 (2017)
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
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Fax: +00 44 (0)131 4513327
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