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28,428 Article Results

Analysis of Distributed Power Flow Controller in Power System Network for Improving Power Flow Control

10.11591/ijeecs.v2.i3.pp510-521
Kuldeep Saini , Aakash Saxena , M.R. Farooqi
In this paper, a new power flow controlling device called Distributed Power Flow Controller (DPFC) is presented that offers the same control capability as the unified power-flow controller (UPFC) but with much lower cost and high reliability. The DPFC eliminates the common DC link within the UPFC, to enable the independent operation of the shunt and the series converter. The D-FACTS concept is employed to the series converter to increase the reliability. Multiple low-rating single-phase converters replace the high-rating three-phase series converter, which significantly reduces the cost and increases the reliability. The active power that is exchanged through the common DC link in the UPFC is now transferred through the transmission line at the 3rd harmonic frequency. The DPFC is modeled in a rotating dq-frame. The modeling and analysis of DPFC in a two area two bus interconnected system is done in MATLAB/Simulink environment and comparison between the DPFC and UPFC considering the power flow and cost are also shown. 
Volume: 2
Issue: 3
Page: 510-521
Publish at: 2016-06-01

State-space Modelling and Digital Controller Design for DC-DC Converter

10.12928/telkomnika.v14i2.3042
Oladimeji; Department of Electrical and Electronics Engineering, Universiti Teknologi PETRONAS, Bander Seri Iskander, 32610 Perak Ibrahim , Nor Zaihar; Department of Electrical and Electronics Engineering, Universiti Teknologi PETRONAS, Bander Seri Iskander, 32610 Perak Yahaya , Nordin; Department of Electrical and Electronics Engineering, Universiti Teknologi PETRONAS, Bander Seri Iskander, 32610 Perak Saad
The recent development in digital technology offers better platform for easy implementation of advance control algorithm in power converter design making digital control a viable alternative to analogue counterpart. Controller design for power converters has been very challenging due to non-linear characteristics of power switches, the supply voltage variability, load current changes and circuit element variation. This paper presents dynamic averaged state-space modelling of non-ideal dc-dc boost converter with parasitic and digital controller design for boost converter using digital redesign and direct digital design methods. The system was simulated in Matlab/Simulink to investigate the dynamic performance of the two controllers’ transient response, control bandwidth and response to variable supply voltage. The results demonstrated fast transient and wide control bandwidth for tight voltage regulation of variable input voltage.
Volume: 14
Issue: 2
Page: 497-506
Publish at: 2016-06-01

Remote Sensing Image Fusion Scheme using Directional Vector in NSCT Domain

10.12928/telkomnika.v14i2.2747
Baohui; Henan Vocational & Technical College of Communications Tian , Lan; Henan Vocational & Technical College of Communications Lan , Hailiang; Zhengzhou University of Light Industry Shi , Yunxia; Zhengzhou University of Light Industry Pei
This paper is under in-depth investigation due to suspicion of possible plagiarism on a high similarity indexA novel remote sensing image fusion scheme is presented for panchromatic and multispectral images, which is based on NonSubsampled Contourlet Transform (NSCT) and Principal Component Analysis (PCA). The fusion principles of the different subband coefficients obtained by the NSCT decomposition are discussed in detail. A PCA-based weighted average principle is presented for the lowpass subbands, and a selection principle based on the variance of the directional vector is presented for the bandpass directional subbands, in which the directional vector is assembled by the NSCT coefficients of the different directional subbands but the same coordinate. The proposed scheme is tested on two sets of remote sensing images and compared with some traditional multiscale transform-based image fusion methods, such as discrete wavelet transform, stationary wavelet transform, dual-tree complex wavelet transform, contourlet transform. Experimental results demonstrate that the proposed scheme provides superior fused image in terms of several relevant quantitative fusion evaluation indexes.
Volume: 14
Issue: 2
Page: 598-606
Publish at: 2016-06-01

Design of AC Charging Interface and Status Acquisition Circuit for Electric Vehicles

10.12928/telkomnika.v14i2.3676
Kun; Zhoukou Normal University Xu , Li; Zhoukou Senior Technical School Li
To address the unreliable charging of new charging interfaces caused by comprehending deviation on China’s alternating current (AC) charging interface standard for electric vehicles, implementation methods of AC charging interface circuit, control pilot (CP) circuit, and status acquisition circuit for electric vehicles were proposed in this study. Basic principle and functions of the CP circuit were discussed, and influences of resistance parameters on voltage state at test point were analyzed. Freescale MC9S12XEQ512 was used as the main controller, and its integrated pulse-width modulation module and analog-to-digital converter module were used to simplify circuit designs. An experimental test on charging interface connection confirmation, CP, output power parameter passing, and real-time charging connection status acquisition was conducted on real vehicles. Results demonstrated that the designed circuits exhibit high security and meet the basic requirements of GB/T20234-2 with regard to AC charging interface characteristics. All test data are within the allowed error range. Furthermore, real-time monitoring of the charging process and security isolation design of signals can effectively improve the system stability. Hence, this technology can be used in AC charge control of electric vehicles.
Volume: 14
Issue: 2
Page: 449-455
Publish at: 2016-06-01

Fuzzy-based Spectral Alignment for Correcting DNA Sequence from Next Generation Sequencer

10.12928/telkomnika.v14i2.2395
Kana Saputra; Bogor Agricultural University S , Wisnu Ananta; Bogor Agricultural University Kusuma , Agus; Bogor Agricultural University Buono
Next generation sequencing technology is able to generate short read in large numbers and in a relatively short in single running programs. Graph based DNA sequence assembly used to handle these big data in assembly step. The graph based DNA sequence assembly is very sensitive to DNA sequencing error. This problem could be solved by performing an error correction step before the assembly process. This research proposed fuzzy inference system (FIS) model based spectral alignment method which can detect and correct DNA sequencing error. The spectral alignment technique was implemented as a pre-processing step before the DNA sequence assembly process. The evaluation was conducted using Velvet assembler. The number of nodes yielded by the Velvet assembler become a measure of the success of error correction. The results shows that FIS model based spectral alignment created small number of nodes and therefore it successfully corrected the DNA reads.
Volume: 14
Issue: 2
Page: 707-714
Publish at: 2016-06-01

Dynamic Stability Analysis of Generator with Power System Stabilizers Using Matlab Simulink

10.11591/ijeecs.v2.i3.pp501-509
Marizan Sulaiman , Hayfaa Mohammed Hussein , Rosli Omar , Zulhisyam Salleh
 The dynamics in single machine been connected to an infinite power system bus is analyzed in this paper. This analysis requires certain amount of system modeling level. The main components of the system models are excitation system, synchronous machine and the Power System Stabilizer. The Simulink /Matlab are used as the programming tool for analyzing this system performance. Design optimization arobust PSS based on Genetic Algorithm (GA) approach has been improvement. A proper design is required for this Power System Stabilizer (PSS) performance using the Particle Swarm Optimization (PSO) to archieve this. Then the implemented of the model and response of the dynamic system is been analyzed. The designed without PSS showed an unacceptable system response since as shown in the simulation results, system response with PSS proven to have improvements and PSS succeeding in  stabilizing an unstable system. Therefore this leads to stability of the performance of the generator.
Volume: 2
Issue: 3
Page: 501-509
Publish at: 2016-06-01

Improved Indoor Location Systems in a Controlled Environments

10.12928/telkomnika.v14i2.2901
Selcuk; Akdeniz University Helhel , Atalay; Akdeniz University Kocakusak
The precise localization by using Wi-Fi Access Point (AP) has become a very important issue for indoor location based services such as marketing, patient follow up and so on. Present AP localization systems are working on specially designed Wi-Fi units, and their algorithms using radio signal strength (RSS) exhibit (relatively) high errors, so industry looks more precise and fast adaptable methods. A new model considering/eliminating strong RSS levels in addition to close distance error elimination algorithm (CDEEA) combined with median filters has been proposed in order to increase the performance of conventional RSS based location systems. Collecting local signal strengths by means of an ordinary WiFi units present on any laptop as a receiver is followed by the application of CDEEA to eliminate strong RSS levels. Median filter is then applied to those eliminated values, and AP based path loss model is generated, adaptivelly. Finally, the proposed algorithm predicts locations within a maximum mean error of 2.96m for 90% precision level. This achievement with an ordinary wifi units present on any commercial laptop is comparably at very good level in literature.
Volume: 14
Issue: 2
Page: 748-756
Publish at: 2016-06-01

An Optimum Database for Isolated Word in Speech Recognition System

10.12928/telkomnika.v14i2.2353
Syifaun; Department of Electrical Engineering and Information Technology, Universitas Gadjah Mada Department of Library and Information Science, Islamic State University Sunan Kalijaga Yogyakarta Nafisah , Oyas; Deparment of Electrical Engineering and Information Technology, Universitas Gadjah Mada Wahyunggoro , Lukito Edi; Deparment of Electrical Engineering and Information Technology, Universitas Gadjah Mada Nugroho
Speech recognition system (ASR) is a technology that allows computers receive the input using the spoken words. This technology requires sample words in the pattern matching process that is stored in the database. There is no reference as the fundamental theory to develop database in ASR. So, the research of database development to optimize the performance of the system is required.  Mel-scale frequency cepstral coefficients (MFCCs) is used to extract the characteristics of speech signal and backpropagation neural network in quantized vector is used to evaluate likelihood the maximum log values to the nearest pattern in the database.  The results shows the robustness of ASR is optimum using 140 samples of data reference for each word with an average of accuracy is 99.95% and duration process is 27.4 msec.  The investigation also reported the gender doesn’t have significantly influence to the accuracy.  From these results it concluded that the performance of ASR can be increased by optimizing the database.
Volume: 14
Issue: 2
Page: 588-597
Publish at: 2016-06-01

A Systematic Design towards Usability for Novice Designers

10.12928/telkomnika.v14i2.3116
Hoo; Universiti Tunku Abdul Rahman Meei Hao , Azizah; Universiti Kebangsaan Malaysia Jaafar
Dependence on intuitive and experiences would add more complexity in the design process. Novice designers would follow the design of any existing systems without direction. This paper proposed a systematic design approach that provides guidance for novice designers in achieving the targeted usability goal using patterns, and evaluating the prototypes in achieving the determined usability goals. The proposed approach involved the cooperation of experts in providing direction to the novice designers in achieving usability goal in the system design. A collective decision both from users and experts would be gather to give a clear decision of a chosen prototype. Two experiments that followed the proposed approach were conducted with 7 groups or 33 undergraduate students. Ten industry experts, 10 field experts and 29 prospective users were involved in evaluating the appropriate use of the tool to assist them in making decision during comparative prototype evaluation. The result from both experiments concluded the systematic approach could help the novice designers to emphasize usability along the design process. It was observed that the achievement of important goals in their designed prototype could be easily done if pattern selection was provided to the novice designers. The designed tool to assist novice designers has high reliability and high acceptance level of appropriate of use in making decision for the preferred prototype.
Volume: 14
Issue: 2
Page: 715-724
Publish at: 2016-06-01

SC-FDMA LTE Performance Through High Altitude Platforms Communications Channel

10.12928/telkomnika.v14i2.2646
Iskandar; Bandung Institute of Technology Iskandar , D.; Bandung Institute of Technology Hidayat
It is known that HAPS is one of the promising wireless infrastructures in the years to come. HAPS exploit many advantages from cellular satellite system as well as from cellular terrestrial system. Therefore, HAPS is envisaged as a novel technology for communication. This paper aims at evaluating the performance of a pilot-based channel estimation for uplink LTE using SC-FDMA over Ricean HAPS communication channel. Pilot-based channel estimation is used to estimate an uplink channel of LTE users who transmit the data to HAPS as a base transceiver station (BTS). Analysis is performed to determine the effect of users elevation angle with respect to user position inside HAPS coverage, LTE channel bandwidth, modulation type, and the Doppler frequency shift effect. We found that user’s elevation angle contribute major effect to the pilot-based channel estimation of LTE SC-FDMA performance. System capability to overcome fading effect that users with low elevation angle would be needed to increase the performance. In particular to keep an acceptable performance, in this paper we compensate the channel bandwidth, changing modulation type, and limit the Doppler effect through vehicle speed limitation.
Volume: 14
Issue: 2
Page: 515-522
Publish at: 2016-06-01

Improved Energy Aware Cluster based Data Routing Scheme for WSN

10.12928/telkomnika.v14i2.3375
Khalid; Universiti Teknologi Malaysia Haseeb , Kamalrulnizam; Universiti Teknologi Malaysia Abu Bakar , Abdul; Universiti Teknologi Malaysia Hanan Abdullah , Tasneem; Universiti Teknologi Malaysia Darwish , Fasee; Universiti Teknologi Malaysia Ullah , Adnan; Quaid-e-Awam University of Engineering, Science and Technology Ahmed
Wireless sensor network (WSN) consists of several tiny devices that are dispersed randomly for gathering network field. Clustering mechanism divides the WSN into different sub-regions called clusters. Individual cluster is consisting of cluster head (CH) and member nodes. The main research challenges behind clustering mechanism are to optimize network overheads with efficient data delivery. Sensor nodes are operated by batteries and practically it is not feasible to replace them during sensing the environment so energy should be effectively utilized among sensors for improving overall network performance. This research paper presents an improved energy aware cluster based data routing (i-ECBR) scheme, by dividing the network regions into uniform sized square partitions and localized CH election mechanism. In addition, consistent end-to-end data routing is performed for improving data dissemination. Simulation results illustrate that our proposed scheme outperforms than existing work in terms of different performance metrics.
Volume: 14
Issue: 2
Page: 531-537
Publish at: 2016-06-01

Semi-supervised Online Multiple Kernel Learning Algorithm for Big Data

10.12928/telkomnika.v14i2.2751
Ning; Shangluo University Liu , Jianhua; Shangluo University Zhao
In order to improve the performance of machine learning in big data, online multiple kernel learning algorithms are proposed in this paper. First, a supervised online multiple kernel learning algorithm for big data (SOMK_bd) is proposed to reduce the computational workload during kernel modification. In SOMK_bd, the traditional kernel learning algorithm is improved and kernel integration is only carried out in the constructed kernel subset. Next, an unsupervised online multiple kernel learning algorithm for big data (UOMK_bd) is proposed. In UOMK_bd, the traditional kernel learning algorithm is improved to adapt to the online environment and data replacement strategy is used to modify the kernel function in unsupervised manner. Then, a semi-supervised online multiple kernel learning algorithm for big data (SSOMK_bd) is proposed. Based on incremental learning, SSOMK_bd makes full use of the abundant information of large scale incomplete labeled data, and uses SOMK_bd and UOMK_bd to update the current reading data. Finally, experiments are conducted on UCI data set and the results show that the proposed algorithms are effective.
Volume: 14
Issue: 2
Page: 638-646
Publish at: 2016-06-01

Critical Success Factor in Monetizing Blog

10.12928/telkomnika.v14i2.3041
Andika; Bina Nusantara University Rizky , Bens; Bina Nusanatara University Pardamean
Blog usage has transformed from its initial function as a digital diary into a legitimate form of mainstream media. Nowadays any member of the public can generate income from blogging through monetization even though various factors affect the results of this process. Four factors were identified: traffic, search engine optimization (SEO), post frequencies, and media usage. This study examines the level of importance of these factors through practical implementation into blogs then quantitatively determine which factor is critical for the success of blog monetization. An empirical analysis based on thirty samples of blogs were performed to assess the impact of the received income. The finding showed that the revenue for most of the blogs increased after the implementation of critical factors with SEO being the most critical of all the factors.
Volume: 14
Issue: 2
Page: 757-761
Publish at: 2016-06-01

Harmonic Suppression Rectangular Patch Antenna with Circularly Polarized

10.12928/telkomnika.v14i2.2394
Nurzaimah; Universiti Teknikal Malaysia Melaka Zainol , Zahriladha; Universiti Teknikal Malaysia Melaka Zakaria , Maisarah; Universiti Teknikal Malaysia Melaka Abu , Mawarni; Universiti Teknikal Malaysia Melaka Mohamed Yunus
The rectangular patch antenna with proximity coupling at 2.45 GHz is designed and printed on FR-4 substrate with dielectric constant 4.3 and loss tangent 0.019. The overall size of proposed antenna gives 36 % reduction of substrate area as compared to conventional designs. The symmetrical arm of inverted U-stub and U-slot embedded on the transmission feed line suppress harmonic signal effectively at second and third order with minimum reflection coefficients of –0.51 dB and -2.28 dB respectively while circularly polarization was obtained by corner truncated and U-slot on the patch element. The return loss is -23.95 dB at fundamental modes with gain 4.61 dB and axial ratio of 1.48 dB.
Volume: 14
Issue: 2
Page: 471-477
Publish at: 2016-06-01

Measurement and Evaluation of Tx/ Rx Antennas for X-Band Radar System

10.12928/telkomnika.v14i2.3291
Folin; Research Center for Electronic and Telecommunication, Indonesian Institute of Sciences Oktafiani , Yuyu; Research Center for Electronic and Telecommunication, Indonesian Institute of Sciences Wahyu , Yusuf Nur; Research Center for Electronic and Telecommunication, Indonesian Institute of Sciences Wijayanto
This paper presents the performance evaluation of antennas for microwave transmission and reception in X-band radar systems. The transmitter (Tx) and receiver (Rx) antennas are fabricated on microstrip array structures. The antennas are connected to microwave circuits with transmission lines, coaxial cables, and microwave combiners and splitters. The designed antennas in X-band microwave operation for Tx and Rx parts were fabricated identically by 4x64 microstrip patch antennasin an array structure. The fabricated antennas were measured for return loss (S11), VSWR, radiation pattern, and Gain. The detail methods for the measurements are reported and their results are also discussed. The measured antenna gain of ~20dBi, and beam-width of ~20degreecan be obtained using the fabricated antennas at 9.4GHz microwave operation.
Volume: 14
Issue: 2
Page: 555-562
Publish at: 2016-06-01
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