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29,905 Article Results

Filtration and water reduction of methyl ester for insulation purpose

10.12928/telkomnika.v17i6.13133
A.; Andalas University Rajab , F. E.; Andalas University Putra , J. S.; Andalas University Ramadhani , M. S. I.; Andalas University Silitonga , R.; Andalas University Kurniawan , K.; Andalas University Qibran , Novison; Andalas University Novison , Melda; Andalas University L. , M. I.; Andalas University Hamid , Kiasatina; University Sains Malaysia A. , M. F.; University Sains Malaysia Akbar , Moh.; University Sains Malaysia Kamarol
An attempt to develop a monoester type insulating oil, especially methyl ester is being conducted and the current results after conducting two kinds of treatment, namely, filtration and water reduction arereported in this paper. Five different samples were prepared from methyl ester oil based on their melting point. The important properties of oil samples such as breakdown voltage, viscosity, water content, acidity, and density were tested, and are evaluated based on the standard specification of natural ester used for the transformer, ASTM D-6871. Another important property, i.e. oxidation stability was also tested and is evaluated by comparing the corresponding result of mineral oil. It is found that the breakdown voltage, the viscosity and the relative density of the oil fulfill the requirements specified by the standard, whereas other properties like water content, acidity and oxidation stability need further improvement.
Volume: 17
Issue: 6
Page: 3183-3190
Publish at: 2019-12-01

Optimization of house purchase recommendation system (HPRS) using genetic algorithm

10.11591/ijeecs.v16.i3.pp1530-1538
K.A.F.A. Samah , I.M. Badarudin , E.E. Odzaly , K.N. Ismail , N.I.S. Nasarudin , N.F. Tahar , M.H. Khairuddin
This paper presents the optimization of house purchase recommendation system (HRPS) using Genetic Algorithm.  Everyone in this world has their own dream house and plan to purchase it depending on their budget and based on the house preferences. Homebuyers face problem in comparing the house property websites according to the factors during the house survey. Subsequently, it is time-consuming in making the decision and they need to bear the transportation cost as they will need to travel to one house developer office to another. In addition, some of the homebuyers felt disappointed when their expectations were not met. Thus, in order to optimize the preferences, in this paper, we present a web-based house purchase recommendation system (HPRS) using a genetic algorithm. Then, it follows by test the functionality and usability of the system. As a result, the system found to function accordingly and obtain more than the average score of system usability scale testing. For further research, it is recommended to add more data to the database and compare with other algorithms.
Volume: 16
Issue: 3
Page: 1530-1538
Publish at: 2019-12-01

Security assessment framework for educational ERP systems

10.11591/ijece.v9i6.pp5570-5585
Hafsa Ashraf , Mamdouh Alenezi , Muhammad Nadeem , Yasir Javid
The educational ERP systems have vulnerabilities at the different layers such as version-specific vulnerabilities, configuration level vulnerabilities and vulnerabilities of the underlying infrastructure. This research has identified security vulnerabilities in an educational ERP system with the help of automated tools; penetration testing tool and public vulnerability repositories (CVE, CCE) at all layers. The identified vulnerabilities are analyzed for any false positives and then clustered with mitigation techniques, available publicly in security vulnerability solution repository like CCE and CWE. These mitigation techniques are mapped over reported vulnerabilities using mapping algorithms. Security vulnerabilities are then prioritized based on the Common Vulnerability Scoring System (CVSS). Finally, open standards-based vulnerability mitigation recommendations are discussed.
Volume: 9
Issue: 6
Page: 5570-5585
Publish at: 2019-12-01

Optimal controllers design for voltage control in Off-grid hybrid power system

10.11591/ijece.v9i6.pp4586-4597
Harsha Anantwar , Shanmukha Sundar , B. R. Laksmikantha
Generally, for remote places extension of grid is uneconomical and difficult. Off-grid hybrid power systems (OGHPS) has  renewable energy sources integrated with conventional sources. OGHPS is very significant as it is the only source of electric supply for remote areas. OGHPS under study  has Induction generator (IG) for wind power generation, Photo-Voltaic source with inverter, Synchronous generator (SG) for Diesel Engine (DE) and load. Over-rated PV-inverter has capacity to supply reactive power.  SG of  DE  has Automatic voltage regulator for excitation control to regulate terminal voltage. Load and IG demands reactive power, causes reactive power imbalance hence voltage fluctuations in OGHPS. To manage reactive power for voltage control, two control structures with Proportional–Integral controller(PI), to control  inverter reactive power and  SG excitation by automatic voltage regulator are incorporated.  Improper tuning of controllers lead  to oscillatory and sluggish response. Hence in this test system both controllers need to be tune optimally. This paper proposes novel intelligent computing algorithm , Enhanced Bacterial forging algorithm (EBFA) for optimal reactive power controller for voltage control in OGHPS. Small signal model of OGHPS with proposed controller is  tested for different disturbances. simulation results  are compared  with conventional  method , proved the effectiveness of EBFA.
Volume: 9
Issue: 6
Page: 4586-4597
Publish at: 2019-12-01

First order parallel coupled BPF with wideband rejection based on SRR and CSRR

10.12928/telkomnika.v17i6.10790
Zaid A.; Al-Mustansiriayah University Abdul Hassain , Amer Abbood; Al-Mustansiriayah University AL-Behadili , Adham R.; Uruk University Azeez
In this paper a new approach for first order Chebyshev parallel coupled Bandpass filter resonant at 1 GHz is presented to obtain better results (wideband rejection, high selectivity and low bandpass insertion loss) compared to conventional design. The proposed filter (a tri-formation consisting of CSRR, SRR and stubs of stepped impedance are loaded microstrip resonator) can be configured, by laying split ring resonator (SRR) and complementary split ring resonator (CSRR) with 50 Ω microstrip lines, in addition to effect of loading two stubs of stepped impedance around center of midline microstrip with impedance line 55.36 Ω of parallel coupled. The proposed filter produces high selectivity from passband to stopband transition equals to 307.5 dB/GHz and an excellent wide stopband performance extend from 1.22 GHz to 5 GHz (harmonics repression till for 5 ƒ0); all are bellow -20 dB excepting one transmission zero of -19 dB, that can be eliminate the harmonic superior frequencies without using any external Bandstop filter. Also, enhancement low bandpass insertion loss level, where it reaches 0.25 dB at fundamental centered frequency (ƒ0 = 0.96 GHz) with 21% bandwidth. The proposed filter is designed and simulated with computer aided of Ansoft HFSS software package which ordinarily used in microwave application.
Volume: 17
Issue: 6
Page: 2704-2712
Publish at: 2019-12-01

Computer vision for purity, phenol, and pH detection of Luwak Coffee Green Bean

10.12928/telkomnika.v17i6.12689
Yusuf; Universitas Brawijaya Hendrawan , Shinta; Universitas Brawijaya Widyaningtyas , Sucipto; Universitas Brawijaya Sucipto
Computer vision as a non-invasive bio-sensing method provided opportunity to detect purity, total phenol, and pH in Luwak coffee green bean. This study aimed to obtain the best Artificial Neural Network (ANN) model to detect the percentage of purity, total phenol, and pH on Luwak coffee green bean by using color features (red-green-blue, gray, hue-saturation-value, hue-saturation-lightness, L*a*b*), and Haralick textural features with color co-occurrence matrix including entropy, energy, contrast, homogeneity, sum mean, variance, correlation, maximum probability, inverse difference moment, and cluster tendency. The best ANN structure was (5 inputs; 30 nodes in hidden layer 1; 40 nodes in hidden layer 2; and 3 outputs) which had training mean square error (MSE) of 0.0085 and validation MSE of 0.0442.
Volume: 17
Issue: 6
Page: 3073-3085
Publish at: 2019-12-01

Power quality analysis based on simulation and MATLAB/Simulink

10.11591/ijeecs.v16.i3.pp1144-1153
Ahmed Salam Hussein , Majli Nema Hawas
This paper in existence a complete system connected to all situations power quality event, which has been achieved using MATLAB/SIMULINK and utilizing parametric equations. In electrical energy allocation system, the disturbances of power quality have emerged as an important matter for usefulness and customers. This design incorporates distribution two capacitor bank, line fault, starting of induction motor, non-linear load and transformer energizing that are usage to simulate diverse kind of voltage sag. In simulate voltage provisional through distribution network produced as a result of effect capacitor bank switching version in the general model. For clarity, this model is advanced with an integrated block and setting in which all event situations are organized for energy quality without scarifying the gist it. This model Integrated is too beneficial to simulate different energy quality waveforms. The performance of the brand new automated categorization algorithms received are appropriate for checking waveforms of power quality.
Volume: 16
Issue: 3
Page: 1144-1153
Publish at: 2019-12-01

Study on the performance indicators for smart grids: a comprehensive review

10.12928/telkomnika.v17i6.13285
Surender Reddy; Woosong University Salkuti
This paper presents a detailed review on performance indicators for smart grid (SG) such as voltage stability enhancement, reliability evaluation, vulnerability assessment, Supervisory Control and Data Acquisition (SCADA) and communication systems. Smart grids reliability assessment can be performed by analytically or by simulation. Analytical method utilizes the load point assessment techniques, whereas the simulation technique uses the Monte Carlo simulation (MCS) technique. The reliability index evaluations will consider the presence or absence of energy storage elements using the simulation technologies such as MCS, and the analytical methods such as systems average interruption frequency index (SAIFI), and other load point indices. This paper also presents the difference between SCADA and substation automation, and the fact that substation automation, though it uses the basic concepts of SCADA, is far more advanced in nature.
Volume: 17
Issue: 6
Page: 2912-2918
Publish at: 2019-12-01

The preliminary study on inverted problem-based learning in biology among science foundation students

10.11591/ijere.v8i4.20294
Azlinah Matawali , Sitty Nur Syafa Bakri , Nur Ramziahrazanah Jumat , Iziana Hani Ismail , Sazmal Effendi Arshad , Wardatul Akmam Din
The emergent of Science, Technology, Engineering and Mathematics (STEM) Education in Malaysia has embarked challenges in higher education system. Conventional teaching methods often cause lower learning gain, fear and bad perceptions among students. The old initiative may also be the cause of students’ demotivation, lower interest in learning a subject or even dropouts. This study was conducted to evaluate the effectiveness of an inverted classroom by using the problem-based method in Biology subject among science foundation students. Students were divided into two groups; experimental (EG) and control (CG) group. A topic in Biology had been selected, and an assessment paper was given to both groups before and after the intervention session. The EG would experience self-learning through given materials and asked to conduct a problem-based learning study case. Meanwhile, the CG would obey the conventional teaching method before given a similar study case. The result reported significant improvement in assessment marks for EG group compared to the CG group. The students’ comparison between the pre- and post-test implies that they have shown positive improvement in understanding the content of the subject tested. This finding will serve as a primary platform to improvise and enhance teaching and learning methodology in biology subject for foundation level.
Volume: 8
Issue: 4
Page: 713-718
Publish at: 2019-12-01

Blind frequency offset estimator for OFDM systems

10.12928/telkomnika.v17i6.11957
Sakina; Badji Mokhtar-Annaba University BP 12 Atoui , Noureddine; Badji Mokhtar-Annaba University BP 12 Doghmane , Saddek; Badji Mokhtar-Annaba University BP 12, Afifi
Orthogonal Frequency Division Multiplexing (OFDM) is of great interest for the development of the fifth-generation technology. It is the cornerstone of Multiple-input multiple-output (MIMO) systems. Even though inter carrier interference (ICI) and inter symbol interference (ISI) have been processed for the fourth-generation standards, they still present a huge problem for the fifth-generation standards. This paper explores the tradeoff between the length of the cyclic prefix and the performances of the OFDM system. It also studies the effect of carrier frequency offset (CFO) on OFDM systems. A blind frequency offset estimator that uses the correlations between the remodulated sequence in the receiver side and the conventional received symbol is presented and a closed form solution is derived. The proposed estimator is derived under short interval when the correlation is high, so it has low computational complexity. Lin and Beek’s estimators are used for comparison. Simulations demonstrate the effectiveness of the proposed estimator under Rayleigh fading channel.
Volume: 17
Issue: 6
Page: 2722-2728
Publish at: 2019-12-01

Cloud connected smart home gas cylinder platform based wifi control

10.11591/ijict.v8i3.pp117-121
C.R. Balamurugan , P. Vijayakumar
Gas sensing technology has become topical research work for quite some time and we also want to protect our home asserts from any kind of hazards. In this work we take an overview on how to protect our home from fire and its safety issues based on wireless sensor network using wifi and cloud technologies. It also showcases the research done on the detection mechanism of leakage of domestic cooking gas at ambient condition. It can detect the fire, leakage of gas or smoke and sends an auto-generated email remotely to intimate the owner. We survey and examine the existing work in security system and its applications.
Volume: 8
Issue: 3
Page: 117-121
Publish at: 2019-12-01

Regenerating face images from multi-spectral palm images using multiple fusion methods

10.12928/telkomnika.v17i6.12857
Raid Rafi; Northern Technical University Al-Nima , Moatasem Yaseen; Northern Technical University Al-Ridha , Farqad Hamid; Northern Technical University Abdulraheem
This paper established a relationship between multi-spectral palm images and a face image based on multiple fusion methods. The first fusion method to be considered is a feature extraction between different multi-spectral palm images, where multi-spectral CASIA database was used. The second fusion method to be considered is a score fusion between two parts of an output face image. Our method suggests that both right and left hands are used, and that each hand aims to produce a significant part of a face image by using a Multi-Layer Perceptron (MLP) network. This will lead to the second fusion part to reconstruct the full-face image, in order to examine its appearance. This topology provided interesting results of Equal Error Rate (EER) equal to 1.99%.
Volume: 17
Issue: 6
Page: 3110-3119
Publish at: 2019-12-01

Optimal volt/var control of distribution system using MOPSO

10.11591/ijeecs.v16.i3.pp1088-1095
Ramesh Babu M , C. Venkatesh Kumar , R. Sreekanth
This paper presents a novel method for solving multi-objective Volt/Var control of radial distribution system. The Volt/Var control is formulated as a multi-objective optimization problem which consists of the following objectives: minimization of real power loss, minimization of total voltage deviation and minimization of number of OLTC’s and capacitor operation and voltage fluctuations for a day-a-head in Distribution system.The Proposed MOPSO Algorithm is used to find the optimal settings of control variables such as On-Load tap changer (OLTC) and Shunt Capacitor. The proposed MOPSO algorithm is tested on a standard IEEE33-bus and 69-bus distribution system.
Volume: 16
Issue: 3
Page: 1088-1095
Publish at: 2019-12-01

Ba[Mg2Al2N4]Eu2+ phosphor for enhancing the optical quality of the 6600K CPW-LEDs

10.12928/telkomnika.v17i6.13090
Van-Duc; Nguyen Tat Thanh University Phan , Duy-Hung; Ton Duc Thang University Ha , Minh; Ton Duc Thang University Tran , Tran Thanh; National Key Laboratory of Digital Control and System Engineerin Trang
Compared with conventional lamps, LED-based light sources have a superior lifetime, efficiency, and reliability, which promise significant reductions in power consumption and pollution from fossil fuel power plants. The main purpose of this paper is proposed and investigated the effect of the concentration of Ba[Mg2Al2N4]Eu2+conversion phosphor on the CCT deviation (D-CCT) and lumen output (LO) of the 6600 K conformal-packaging white LEDs (CPW-LEDs). For this purpose, we used the Light Tools and Mat Lab software to investigate this problem. From the research results, we can state that the concentration of the red phosphor crucially influenced on the optical quality of the 6600 K CPW-LEDs. The D-CCT can be decreased from 4700K to 2500K, and the LO can be increased from 600 lm. to 1200 lm. This research can provide the new recommendation for LEDs industry at this time.
Volume: 17
Issue: 6
Page: 2926-2930
Publish at: 2019-12-01

Robust optmized control of multi levels STATCOM

10.11591/ijeecs.v16.i3.pp1203-1212
Tedjini Hamza , Messaoud Fatima Zahra , Kadri Boufeldja
Reactive power compensation is an essential part of a power system and the static synchronous compensator (STATCOM) plays an important role in controlling the reactive power flow over the transmission line. The basic building block of the STATCOM is a voltage source inverter (VSI) that generates a synchronous sinusoidal voltage and because of the high MVA ratings, it would be expensive to provide independent, equal, regulated dc voltage sources to power the multilevel converters which are presently proposed for STATCOMs. Dc voltage sources can be derived from the dc link capacitances which are charged by the rectified ac power. In this paper a new stronger control combined of nonlinear control based Lyapunov’s theorem and Ant Colony Algorithm (ACA) to maintain stability of multilevel STATCOM and the utility.
Volume: 16
Issue: 3
Page: 1203-1212
Publish at: 2019-12-01
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