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29,758 Article Results

A Miniature L-slot Microstrip Printed Antenna for RFID

10.12928/telkomnika.v16i5.9378
Mohamed; Hassan 1st University Ihamji , El hassane; Hassan 1st University Abdelmounim , Jamal; Hassan 1st University Zbitou , Hamid; Moulay Ismail University Bennis , Mohamed; Microwave Group Latrach
This work presents a miniature microstrip antenna at 2.45 GHz by using the slots technique. This microstrip antenna is fed by a CPW technique and designed for RFID reader system on FR4 substrate. A size reduction equal to 66.6% has been obtained compared to the conventional rectangular microstrip antenna. The total area of the final circuit is 19x31 mm2. The validated antenna has good matching input impedance with a stable radiation pattern, a loss return of -40 dB, and a gain of 1.78 dBi, a prototype of the proposed antenna has been fabricated and measured.
Volume: 16
Issue: 5
Page: 1923-1930
Publish at: 2018-10-01

Load Flow Based Voltage Stability Indices for Voltage Stability and Contingency Analysis for Optimal Location of STATCOM in Distribution Network with Integrated Distributed Generation Unit

10.12928/telkomnika.v16i5.10577
Ibrahim; University Kuala Lumpur British Malaysian Institute (UniKL BMI) Alhamrouni , M. A; University Kuala Lumpur British Malaysian Institute (UniKL BMI) Alif , Bazilah; University Kuala Lumpur British Malaysian Institute (UniKL BMI) Ismail , Mohamed; Universiti Sains Malaysia Salem , Awang; Universiti Teknologi Malaysia Jusoh , T.; Universitas Ahmad Dahlan Sutikno
Electrical power system is growing rapidly with the current increasing demand. One of many important issues being faced in power system is the voltage instability. With that being said, this work investigates the voltage stability indices with contingency analysis used in order to determine the voltage stability of the network system. These approaches are used to detect and avoid voltage instability in the distribution network. The behavior of the distribution network is determined based on the contingency analysis. STATCOM is injected into selected buses in the distribution network of the system to determine the system’s stability during the contingency condition. Distributed generation (DG) is utilized to enhance the network stability. Different scenarios have been assumed in order to test the proposed technique under different conditions. The work has been implemented in Digsilent power factory environment. The proposed technique has been tested on IEEE 30 bus system. Promising results have been obtained with respect to previous published literature, in term of identifying the weak buses and enhancing the overall stability of the network.
Volume: 16
Issue: 5
Page: 2302-2315
Publish at: 2018-10-01

Tropospheric Scintillation with Rain Attenuation of Ku Band at Tropical Region

10.12928/telkomnika.v16i5.10002
Ibtihal F; Universiti Teknologi Malaysia El-shami , Lam Hong; Universiti Teknologi Malaysia Yin , Jafri; Universiti Teknologi Malaysia Din , Ali l; College of Electrical and Electronics Technology Benghazi Elgayar , Manhal; Universiti Teknologi Malaysia Alhilali
Tropospheric scintillation can become a significant impairment in satellite communication systems, especially in tropical regions with frequencies higher than 10 GHz, the attenuation is dramatically affecting the scintillation. This work concentrates on those aspects in equatorial Johor Bahru, Malaysia, based on a one-year Ku-band propagation measurement campaign, utilizing the equipment of Direct Broadcast Receiver (DBR) and Automatic Weather Station (AWS). This study investigates the relationship between wet scintillation and rain attenuation using experimental measurement and concentrate on the probability density function (PDF) of different scintillation parameters. From the results, it is concluded that wet scintillation intensity increases with rain attenuation. Thus, the relationship can be phrased by linear equations or power-law. The PDFs of wet scintillation intensity, adapted to a given rain attenuation level, are found lognormally distributed, leading to selection of method for determining the relation between conditional PDFs and rain attenuation.
Volume: 16
Issue: 5
Page: 1982-1987
Publish at: 2018-10-01

Performance of MPLS-based Virtual Private Networks and Classic Virtual Private Networks Using Advanced Metrics

10.12928/telkomnika.v16i5.7326
Kennedy; Covenant University Okokpujie , Olamilekan; Covenant University Shobayo , Etinosa; Covenant University Noma-Osaghae , Okokpujie; Covenant University Imhade , Obinna; Covenant University Okoyeigbo
Multiprotocol Label Switching (MPLS) is effective in managing and utilizing available network bandwidth. It has advanced security features and a lower time delay. The existing literature has covered the performance of MPLS-based networks in relation to conventional Internet Protocol (IP) networks. But, too few literatures exist on the performance of MPLS-based Virtual Private Networks (VPN) in relation to traditional VPN networks. In this paper, a comparison is made between the effectiveness of the MPLS-VPN network and a classic VPN network using simulation studies done on OPNET®. The performance metrics used to carry out the comparison include; End to End Delay, Voice Packet Sent/Received and Label Switched Path’s Traffic. The simulation study was carried out with Voice over Internet Protocol (VoIP) as the test bed. The result of the study showed that MPLS-based VPN networks outperform classic VPN networks.
Volume: 16
Issue: 5
Page: 2073-2081
Publish at: 2018-10-01

Critical Review of Different Methods for Siting and Sizing Distributed-generators

10.12928/telkomnika.v16i5.9693
Shomefun T; Covenant University S , Ademola; Covenant University A , Awosope CO; Covenant University A , Adekitan A; Covenant University I
Due to several benefits attached to distributed generators such as reduction in line losses, improved voltage profile, reliable system etc., the study on how to optimally site and size distributed generators has been on the increase for more than two decades. This has propelled several researchers to explore various scientific and engineering powerful simulation tools, valid and reliable scientific methods like analytical, meta-heuristic and hybrid methods to optimally place and size distributed generator(s) for optimal benefits. This study gives a critical review of different methods used in siting and sizing distributed generators alongside their results, test systems and gaps in literature.
Volume: 16
Issue: 5
Page: 2395-2405
Publish at: 2018-10-01

About Quality of Optical Channels in Wavelength Division Multiplexing Systems of Optic Fibers

10.12928/telkomnika.v16i5.10300
Mirazimova Gulnora; Tashkent University of Information Technologies Hasanovna
Researches and the analysis of factors of the systems influencing quality with division according to radiation wavelength are given in article. Especially the communication quality in systems with wave division of channels is influenced by hindrances from Four Wave Mixing. In this regard the technique of definition of number of products of nonlinear effect of Four Wave Mixing getting to ranges of working channels, results of calculation of combinational products for the different number of channels in systems with division according to radiation wavelength is given. Power of a hindrance of Four Wave Mixing in systems with wave division of channels is calculated. Methods of reduction of influences of these nonlinear effects are considered. Conclusions and recommendations on ensuring quality of optical channels are provided in systems with wave division.
Volume: 16
Issue: 5
Page: 2005-2013
Publish at: 2018-10-01

A Hardware Model to Measure Motion Estimation with Bit Plane Matching Algorithm

10.12928/telkomnika.v16i5.7672
Shaik Asif; Middle East College Hussain , Chandrashekar; Middle East College Ramaiah , S. Javeed; Sultanate of Oman Hussain
The multistep approach involving combination of techniques is referred as motion estimation. The proposed approach is an adaptive control system to measure the motion from starting point to limit of search. The motion patterns are used to analyze and avoid stationary regions of image. The algorithm proposed is robust efficient and the calculations justify its advantages. The motivation of the work is to maximize the encoding speed and visual quality with the help of motion vector algorithm. In this work a hardware model is developed in which a frame of pictures are captured and sent via serial port to the system. MATLAB simulation tool is used to detect the motion among the picture frame. Once any motion is detected that signal is sent to the hardware which will give the appropriate sign accordingly. This system is developed on two platforms (hardware as well software) to estimate and measure the motion vectors.
Volume: 16
Issue: 5
Page: 2091-2100
Publish at: 2018-10-01

Review on Public Key Cryptography Scheme-Based Performance Metrics

10.11591/ijeecs.v12.i1.pp386-392
Jasmin Ilyani Ahmad , Roshidi Din , Mazida Ahmad
Cryptography is a method used to establish secure data communication. The goal of cryptography is to send data to satisfy the criteria of confidentiality, data integrity, authentication and non-repudiation. In line with the goals, the performance metrics is the important evaluation criteria to be analyzed. This paper presents the review of performance metrics of Public Key Cryptography (PKC) that had been analyzed based on the PKC scheme from the previous researchers’ effort since the last four decades. It also displayed the research pattern in different performance metrics over the years. The aim of this paper is to identify the key performance metrics which addressed by the researchers in previous studies. Finally, the critical concern of this paper which shows the overall PKC performance metrics also presented in this paper.
Volume: 12
Issue: 1
Page: 386-392
Publish at: 2018-10-01

A Comparative Modeling and Analysis of Voltage Variation by Using Spectrogram

10.12928/telkomnika.v16i5.9493
Weihown; Universiti Teknikal Malaysia Melaka (UTeM) Tee , AR; Universiti Teknikal Malaysia Melaka (UTeM) Abdullah , T; Universitas Ahmad Dahlan (UAD) Sutikno , MH; CeRIA, UTeM Jopri , M; CeRIA, UTeM Manap
In this paper, the power quality (PQ) disturbance which is the voltage variations consist of voltage swell, sag and interruption are model and analyze. Different types of voltage variations PQ disturbances models are developed and created by using MATLAB/Simulink as well as mathematical models. The mathematical and Simulink model are used to compare in terms of time-frequency representation (TFR). The Simulink models include shutting down enormouscapacities from system to resemble voltage swell, large loads energizing and three-phase fault to simulate voltage sag as well as implementing permanent three-phase fault to simulate voltage interruption. The signals generated are analyzed by using linear time-frequency distribution (TFD). The signal parameters such as root mean square voltage (Vrms), total harmonic distortion (THD) and power value are estimated from the TFR to identify the characteristics of the voltage variation. The results of analysis on the PQ disturbance waveforms generated are identical to the actual real-time PQ signals and the models can be modified to any desired situation respectively. The PQ waveforms obtained are suitable to be further analyzed.
Volume: 16
Issue: 5
Page: 2385-2394
Publish at: 2018-10-01

Fast Ant Colony Optimization for Clustering

10.11591/ijeecs.v12.i1.pp78-86
Abba Suganda Girsang , Tjeng Wawan Cenggoro , Ko-Wei Huang
Data clustering is popular data analysis approaches, which used to organizing data into sensible clusters based on similarity measure, where data within a cluster are similar to each other but dissimilar to that of another cluster. In the recently, the cluster problem has been proven as NP-hard problem, thus, it can be solved with meta-heuristic algorithms, such as the particle swarm optimization (PSO), genetic algorithm (GA), and ant colony optimization (ACO), respectively. This paper proposes an algorithm called Fast Ant Colony Optimization for Clustering (FACOC) to reduce the computation time of Ant Colony Optimization (ACO) in clustering problem. FACOC is developed by the motivation that a redundant computation is occurred in ACO for clustering. This redundant computation can be cut in order to reduce the computation time of ACO for clustering. The proposed FACOC algorithm was verified on 5 well-known benchmarks. Experimental result shows that by cutting this redundant computation, the computation time can be reduced about 28% while only suffering a small quality degradation.
Volume: 12
Issue: 1
Page: 78-86
Publish at: 2018-10-01

Establishment of Standard Reference Environment for Photovoltaic Nominal Operating Cell Temperature Testing with Dedicated Approach for Tropical Region

10.11591/ijeecs.v12.i1.pp433-440
M.M.M. Hanifah , H. Zainuddin , M.Z. Hussin
This paper presents the establishment of Standard Reference Environment (SRE) for photovoltaic (PV) Nominal Operating Cell Temperature (NOCT) testing in Malaysia representing one of the countries that lies in tropical region. From a field testing conducted, 12-months data of six parameters namely solar irradiance (SI), ambient temperature (AT), relative humidity (RH), wind speed (WS), wind direction (WD), module temperature (MT) and open circuit voltage were analysed to determine the median SI and the median AT.  From the analysis, the median SI and the median AT are 228 W/m2 and 30 °C respectively.  However, these results show that the current approach in determining SRE using median ambient parameters is not suitable for tropical Malaysia based on the percentage error of approximately   30 %. Due to this, the proposed approach applied in this study is determining the corresponding AT of the same SI (800 W/m2) used in present SRE of international standard. Thus, the new proposed SI and AT for SRE in this study are 800W/m2 and 31°C respectively. The SRE found in this study is determined using dedicated approach to suit tropical climate in deriving a more accurate NOCT for tropical region.
Volume: 12
Issue: 1
Page: 433-440
Publish at: 2018-10-01

Techno-economic Viability and Energy Conversion Analysis of RHES with Less Weight/Area

10.12928/telkomnika.v16i5.8897
Mohammed Kdair; University of Technology Abd , Hadeel Nasrat; University of Technology Abdullah , Haishun; Huazhong University of Science & Technology Sun , Shijie; Huazhong University of Science & Technology Cheng
This article proposes a new strategy to find the optimal location, configuration and size of the Renewable (wind-photovoltaic-diesel-battery) Hybrid Energy Systems (RHES (off-grid)). This study has two steps: first, the proposaltoa strategybased on a weather change to find the optimal location in Iraq using Hybrid Optimization Model for Electric-Renewables (HOMER) software. Second, the study will examine the influence of the techno-economic viability from side less weight and area on the optimal configuration/size of the RHES, which gives the maximum output power. A period of one-year for meteorological data for both solar radiation and wind speed has used. Finally, simulation results indicated that the optimal location for this RHES is the AL Harithah location. The analysis has shown that RHES can supply 89% of the load demands by renewable-energy. It is also successful in reducing the area required for installation of the RHES about 28%.
Volume: 16
Issue: 5
Page: 2331-2341
Publish at: 2018-10-01

Implementation of E-Voting System for Student Union Government Elections

10.12928/telkomnika.v16i5.9739
Aderibigbe I.; Covenant University Adekitan , Victor O.; Covenant University Matthews , Temitope M.; Covenant University John , Stanley; Covenant Univeristy Uzairue
Several records of violence during student body elections in higher institutions of learning can be found dating back to the 1988 Abu crisis. The causal factors are multifaceted, involving both internal factors within the institution and external factors, and interest parties like main stream politicians. Suspicion of the possibility of rigging during a planned election can trigger pre-election violence, while alleged rigging during the election or the vote counting process is the major cause of election unrest during student government elections. The voting process is typically manual, and it is done through the use of ballot boxes and papers. This is error prone, inefficient and susceptible to rigging. Preventing mistrust-induced election violence requires the deployment of a trustworthy alternative to the paper ballot system. In this study, an electronic voting system is developed using Visual Basic and Microsoft Access Database. The application performs voter authentication by verifying a pre-issued pin which is unique for each voter. The system is accurate and engages the participation and login of agents who are representatives of the candidates’ contesting for various offices thereby building trust in the process.
Volume: 16
Issue: 5
Page: 2155-2164
Publish at: 2018-10-01

IT Service Management System Measurement using ISO20000-1 and ISO15504-8: Developing a Solution-Mediated Process Assessment Tool to Enable Transparent and SMS Process Assessment

10.11591/ijece.v8i5.pp4023-4032
Imam Asrowardi , Septafiansyah Dwi Putra , Eko Subyantoro , Norzaidi Haji Mohd Daud
Information technology is about not only hardware, software, communication infrastructure and communication infrastructure but also how to manage services. Information technology plays an increasingly important role in developing the structure and functions of public and private sectors. Service measurement plays an important role in IT service management (ITSM) that is one of the subfields of Services Computing science. ITSM is a big part of service science, a science field that combines computer science, operation research engineering, business strategy, management science, and organizational theory. Performance measurement from each of IT services is absolutely needed and is important in the continuous development of ITSM. These research provide good technical knowledge about the measuring ITSM with some requirements. In this paper we suggest the metrics in each service processes enables organizations to predict a direction for active process enhancement and to identify if the goal of process can achieve. This objective process metrics based on ISO/IEC 15504-8 and PRM ISO/IEC 20000-4 refinement. The output of this research, in the form of metrics and tools for any type organizational use.
Volume: 8
Issue: 5
Page: 4023-4032
Publish at: 2018-10-01

Impact of Combine Dithering and Modulators to Mitigate Noise in Radio Over Fiber System

10.11591/ijeecs.v12.i1.pp428-432
Fakhriy Hario , Eka Maulana , Hadi Suyono , Rini N Hasanah , Sholeh H Pramono
A well-prepared Radio over Fiber (RoF) is a technology that combines two transmission technologies, radio and optical fiber transmissions. The study focused on the characteristics and problems of the optical fiber medium. One of the problems in the optical fiber is the effect of nonlinear characteristic, which caused by the high light intensity in the optical fiber core with extended interaction area in a single mode fiber (SMF). This characteristic reduces the output width and creates a pulse broadening. The nonlinear characteristics discussed in this study focused on SPM (self-phase modulation) and GVD (Group Velocity Dispersion). To overcome the nonlinear problems, this study presented a method to make the noise-resistant transmitted signal and improve the optical fiber power range. The fundamental of this study was developing similarities of previous studies regarding nonlinearity in the optical fiber. The results show that the use of two modulators combined with the amplification generated the signal with smoother spectrum, which means that the spectrum distribution was more uniform. There was 61.5 % increase of the peak power of the output signal after amplification using an optical amplifier.
Volume: 12
Issue: 1
Page: 428-432
Publish at: 2018-10-01
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