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31,456 Article Results

The development of an ontology model for early identification of children with specific learning disabilities

10.11591/ijece.v9i6.pp5486-5494
Rosmayati Mohemad , Nur Fadila Akma Mamat , Noor Maizura Mohamad Noor , Arifah Che Alhadi
Ontology-based knowledge representation is explored in special education environment as not much attention has been given to the area of specific learning disabilities such as dyslexia, dysgraphia and dyscalculia. Therefore, this paper aims to capture the knowledge in special education domain, represent the knowledge using ontology-based approach and make it efficient for early identification of children who might have specific learning disabilities. In this paper, the step-by-step development process of the ontology is presented by following the five phases of ontological engineering approach, which consists of specification, conceptualization, formalization, implementation, and maintenance. The details of the ontological model’s content and structure is built and the applicability of the ontology for early identification and recommendation is demonstrated.
Volume: 9
Issue: 6
Page: 5486-5494
Publish at: 2019-12-01

Wireless power transfer through metal using inductive link

10.11591/ijpeds.v10.i4.pp1906-1913
Tuan Anh Vu , Chi Van Pham , Anh-Vu Pham , Christopher S. Gardner
This paper presents a highly efficient power transfer system based on a co-design of a class-E power amplifier (PA) and a pair of inductively coupled Helical coils for through-metal-wall power transfer. Power is transferred wirelessly through a 3.1-mm thick aluminum barrier without any physical penetration and contact. Measurement results show that the class-E PA achieves a peak power gain of 25.2 dB and a maximum collector efficiency of 57.3%, all at 200 Hz. The proposed system obtains a maximum power transfer efficiency of 9% and it can deliver 5 W power to the receiver side through the aluminum barrier.
Volume: 10
Issue: 4
Page: 1906-1913
Publish at: 2019-12-01

Impacts of photovoltaic power source intermittence on a distribution network

10.11591/ijece.v9i6.pp5134-5142
Oumaima Garfi , Helmi Aloui , Nadia Chaker
The integration of the photovoltaic (PV) solar systems into distribution networks has brought new challenges to the network planners. One of the most interesting is to prevent the impacts of the PV intermittent character on the steady state system operation conditions. This work is aimed to investigate such effect on voltage performance, conventional generator daily behavior and automatic voltage regulator operation. Simulations were conducted on a 33-bus IEEE radial distribution power system. In order to provide a reliable study, a real PV power profile was considered. Obtained results over a period of 24 hours revealed that the PV integration contributes to an enhancement of the overall voltage profile, a considerable saving in the total amount of the produced active power and a reduction of power losses. However, the PV intermittent character causes significant transformation in buses voltages daily profiles as well as changes in production plan. To sum up, this paper reports the alterations, caused by the PV source intermittence, which must be taken into consideration by the distribution networks planners to maintain the overall network parameters within safe operating condition
Volume: 9
Issue: 6
Page: 5134-5142
Publish at: 2019-12-01

Direct controls for wind turbine with PMSG used on the real wind profile of Essaouira-Morocco city

10.11591/ijeecs.v16.i3.pp1229-1239
Dalila Hammoumi , Chakib El Bekkali , Mohammed Karim , Mohammed Taoussi , Najib El Ouanjli , Badre Bossoufi
This article presents the use of a permanent magnet synchronous generator (PMSG) for the wind energy production and electrical energy injection produced into an electrical grid. The objective is to perform modeling and direct control of the Wind Energy conversion System (WECS), taking into account the problems of wind speed variations and generator maintenance.  The direct torque control (DTC) is applied to the machine-side converter and direct power control (DPC) is applied to the grid-side converter. The performance of WECS is tested in MATLAB / SIMULINK environment simulation with a real wind profile of Essaouira-Morroco city. The simulation results obtained show that the proposed direct controls provide high performance in terms of setpoint tracking, speed, stability and power quality.
Volume: 16
Issue: 3
Page: 1229-1239
Publish at: 2019-12-01

Genetic algorithm to improve power output of photovoltaic system under partial shaded condition

10.11591/ijpeds.v10.i4.pp2182-2189
Abdalla Eltigani Ibrahim , Nursyarizal Mohd Nor , Illani Binti Mohd Nawi , Mohd Fakhizan Ramlie , Khairul Nisak Mohd
The Partial Shaded Condition (PSC) is a process of non-optimal power capture in photovoltaic (PV) system; it will happen when one or all the PV solar cells get shaded by external factors. This phenomenon makes a sudden change in cell irradiance and lead to non-optimal power capture and reduces the generated power in PV systems. Cell under PSC generates one global peak (GP) and many local peaks (LPs), but the tracking of GP under (PSCs) effectively are still a big challenge to the researchers. In this paper, Fuzzy Logic Control (FLC) and optimized FLC algorithms were developed to track the PV power during the PSCs. The configuration of both algorithms are designed, simulated and evaluated using MATLAB/Simulink and their performance was compared with other literature techniques to study their capability to track the MPPT under PSCs. Proposed GA-FLC achieved 0.7 S as tracking time to find and track the Global Peak of Maximum power Point (GMPP) under PSCs and the usage of buck/boost converter in this technique achieved 98.5% of tracking accuracy. GA-FLC shows good dynamic performance in terms of tracking accuracy and complexity under PSCs compared to other techniques.
Volume: 10
Issue: 4
Page: 2182-2189
Publish at: 2019-12-01

Extended family of DC-DC Quasi-Z-Source converters

10.11591/ijece.v9i6.pp4540-4555
Muhammad Ado , Awang Jusoh , Tole Sutikno
The family of DC-DC q-ZSCs is extended from two to three classes and four to six members. All the members were analyzed based on efficient duty ratio range (RDeff) and general duty ratio range (RDgen). Findings showed that similar to the traditional buck-boost converter (BBC), each of the topologies is theoretically capable of inverted buck-boost (BB) operation for the RDgen with additional advantages but differed according to class in how the gains are achieved. The new topologies have advantages of BB capability at the RDeff, continuous and operable duty ratio range with unity gain at  contrary to existing topologies where undefined or zero gain is produced. Potential applications of each class were discussed with suitable topologies for applications such as fuel cells, photovoltaic, uninterruptible power supply (UPS), hybrid energy storage and load levelling systems identified.
Volume: 9
Issue: 6
Page: 4540-4555
Publish at: 2019-12-01

Development of crack on composite detection sensor using magnetic induction concept

10.11591/ijece.v9i6.pp5644-5652
N. I. Ismail , W. N. A. Rashid , N. Lokmanulhakim
A crack detection is very important to control the quality of the composite itself that been widely used in industries. There are quite a numbers of techniques which are used to detect the crack such as visual inspection, radiography, ultrasonic, eddy current magnetic particle, and penetrant testing. In this paper, it focuses on designing and implementing the system to detect a crack on the composite material using magnetic induction concept. At the early stage, the miniature of composite detection sensor using magnetic induction concept is designed using Comsol Multiphysics software to see the current induced from the system. The current value from the sensor is measured based on magnetic induction concept. A complete design of a system then is designed which include the sensor design, the main controller unit design and Bluetooth electronic application. The experiment results show that the magnetic induction concept can be used to detect crack by changing the value of current. When crack occurs the value of current will decrease due to the changes of magnetic induction.
Volume: 9
Issue: 6
Page: 5644-5652
Publish at: 2019-12-01

Predicting fatalities among shark attacks: comparison of classifiers

10.11591/ijai.v8.i4.pp360-366
Lim Mei Shi , Aida Mustapha , Yana Mazwin Mohmad Hassim
This paper presents the comparisons of different classifiers on predicting Shark attack fatalities. In this study, we are comparing two classifiers which are Support vector machines (SVMs) and Bayes Point Machines (BPMs) on Shark attacks dataset. The comparison of the classifiers were based on the accuracy, recall, precision and F1-score as the performance measurement. The results obtained from this study showed that BPMs predicted the fatality of shack attack victim experiment with higher accuracy and precision than the SVMs because BPMs have “average” identifier which can minimize the probabilistic error measure. From this experiment, it is concluded that BPMs are more suitable in predicting fatality of shark attack victim as BPMs is an improvement of SVMs.
Volume: 8
Issue: 4
Page: 360-366
Publish at: 2019-12-01

Proposal and design methodology of switching mode low dropout regulator for Bio-medical applications

10.11591/ijece.v9i6.pp5046-5059
Kenya Kondo , Hiroki Tamura , Koichi Tanno
The switching operation based low dropout (LDO) regulator utilizing on-off control is pre-sented. It consists of simple circuit elements which are comparator, some logic gates, switched capacitor and feedback circuit. In this study, we target the application to the power supply circuit for the analog front end (AFE) of bio-medical system (such as daily-used bio-monitoring devices) whose required maximum load current is 50 A. In this paper, the design procedure of the proposed LDO has been clarified and actual circuit design using the procedure has been done. The proposed LDO has been evaluated by SPICE simulation using 1P 2M 0.6 m CMOS process device parameters. From simulation results, we could confirm that the low quiescent current of 1 A with the output ripple of 5 mVpp. The circuit area is 0.0173 mm2 in spite of using 0.6 m design rules. The proposed circuit is suitable for adopting to the light load and low frequency applications.
Volume: 9
Issue: 6
Page: 5046-5059
Publish at: 2019-12-01

Classifiers ensemble and synthetic minority oversampling techniques for academic performance prediction

10.11591/ijict.v8i3.pp122-127
Abdulazeez Yusuf , Ayuba John
The increasing need for data driven decision making recently has resulted in the application of data mining in various fields including the educational sector which is referred to as educational data mining. The need for improving the performance of data mining models has also been identified as a gap for future researcher. In Nigeria, higher educational institutions collect various students’ data, but these data are rarely used in any decision or policy making to improve the academic performance of students. This research work, attempts to improve the performance of data mining models for predicting students’ academic performance using stacking classifiers ensemble and synthetic minority over-sampling techniques. The research was conducted by adopting and evaluating the performance of J48, IBK and SMO classifiers. The individual classifiers models, standard stacking classifier ensemble model and stacking classifiers ensemble model were trained and tested on 206 students’ data set from the faculty of science federal university Dutse. Students’ specific previous academic performance records at Unified Tertiary Matriculation Examination, Senior Secondary Certificate Examination and first year Cumulative Grade Point Average of students are used as data inputs in WEKA 3.9.1 data mining tool to predict students’ graduation classes of degrees at undergraduate level. The result shows that application of synthetic minority over-sampling technique for class balancing improves all the various models performance with the proposed modified stacking classifiers ensemble model outperforming the various classifiers models in both performance accuracy and RSME values making it the best model.
Volume: 8
Issue: 3
Page: 122-127
Publish at: 2019-12-01

Comparative analysis of cascaded fuzzy-PI controllers based-MPPT and perturb and observe MPPT in a grid-connected PV system operating under different weather and loading conditions

10.11591/ijpeds.v10.i4.pp1986-1994
Harici Otmane , Youssef Mouloudi , Bendjebbar Mokhtar
In this paper, a comparison is carried out between MPPT technique using a hybrid cascaded Fuzzy-PI Controller and Perturb and Observe (P&O) MPPT technique. The two techniques are compared in a system which consists of a photovoltaic system connected to a grid via a two-level three-phase inverter. The P&O and Fuzzy-PI techniques are examined under different weather conditions, namely, ramp change in irradiation level and ramp change in temperature levels. Disturbances represented by fluctuations in power demand from the utility grid is generated to assess the robustness of each of the two controllers. The Fuzzy-PI based MPPT, has  proved its excellent tracking and robustness against abrupt perturbations. Simulations of the system performances using the two regulators are performed to validate the conceptual standings.
Volume: 10
Issue: 4
Page: 1986-1994
Publish at: 2019-12-01

Road flood warning system with information dissemination via social media

10.11591/ijece.v9i6.pp4979-4987
Ertie Cusipag Abana , Cindy Verli Dayag , Vanessa Mae Valencia , Princess Hipolito Talosig , John Paulo Ratilla , Gladys Galat
Flooding is one of the most devastating natural disasters in the world. It occurs when water from heavy rains exceeds the capacity of the river banks into which it runs. Some roads are also being affected when this natural phenomenon happens which lead to closure of roads. This closure, however, are often dissiminated late to the people that are passing through the closed roads. For this purpose, a Road Flood Warning System with Information Dissemination via Social Media has been developed to provide timely flood alert information to the public. The system determines the depth of the water through an ultrasonic sensor and disseminates the data gathered to the Internet through the use of social media sites specifically Twitter and Facebook. Moreover, the system has a LED matrix and light emitting diode to display whether the roads are passable during the occurrence of floods. The test results on the performance of ultrasonic sensor showed an accuracy of 98.69% while dissemination of information was 90% successful.
Volume: 9
Issue: 6
Page: 4979-4987
Publish at: 2019-12-01

High performance DC/DC buck converter using sliding mode controller

10.11591/ijpeds.v10.i4.pp1806-1814
Mustafa Abbas Fadel Al-Qaisi , Mohanad A. Shehab , Ammar Al-Gizi , Mohammed Al-Saadi
This paper investigated the performance of the sliding mode control technique for dc/dc converter using frequency response method. The applications of the step down type switching regulator) buck converter (are found in the devices that use batteries as power source like laptop, cell phones, electric vehicle, and recently, it  has also been used in the renewable energy processing, as a maximum output power can be achieved at higher efficiency. In order to optimize the efficiency and for convenient power management, the issues like power on transients, the effect of load variation, Switching and Electromagnetic interference (EMI) losses has to be overcome for which controllers are used. In the proposed method, pulse width modulation (PWM) based on proportional-integral-derivative sliding mode voltage controller (PID SMVC) is designed for a buck converter and the response for appropriate control parameters has been obtained. The system stability has been examined and analyzed from the performance characteristics, which shows clearly that the buck converter controlled by the sliding mode controller has fast dynamic response and it’s very efficient for various applications.
Volume: 10
Issue: 4
Page: 1806-1814
Publish at: 2019-12-01

Ensemble deep learning for tuberculosis detection using chest X-Ray and canny edge detected images

10.11591/ijai.v8.i4.pp429-435
Stefanus Kieu Tao Hwa , Mohd Hanafi Ahmad Hijazi , Abdullah Bade , Razali Yaakob , Mohammad Saffree Jeffree
Tuberculosis (TB) is a disease caused by Mycobacterium Tuberculosis. Detection of TB at an early stage reduces mortality. Early stage TB is usually diagnosed using chest x-ray inspection. Since TB and lung cancer mimic each other, it is a challenge for the radiologist to avoid misdiagnosis. This paper presents an ensemble deep learning for TB detection using chest x-ray and Canny edge detected images. This method introduces a new type of feature for the TB detection classifiers, thereby increasing the diversity of errors of the base classifiers. The first set of features were extracted from the original x-ray images, while the second set of features were extracted from the edge detected image. To evaluate the proposed approach, two publicly available datasets were used. The results show that the proposed ensemble method produced the best accuracy of 89.77%, sensitivity of 90.91% and specificity of 88.64%. This indicates that using different types of features extracted from different types of images can improve the detection rate.
Volume: 8
Issue: 4
Page: 429-435
Publish at: 2019-12-01

Modeling and simulation of graphene field effect transistor (GFET)

10.11591/ijece.v9i6.pp4826-4835
Nanda B. S. , Puttaswamy P. S.
Graphene based top-gated Field effect transistor (GFET) is designed and simulated using the device simulator packages. The paper describes fabrication process and the device simulation aspects of the GFET device. Two devices with different gate lengths of 200nm and 350nm are simulated. Device simulations are carried out in open source TCAD software package. The results indicate a depletion FET type operation in which ON/OFF current ratio of 2.25 is obtained.
Volume: 9
Issue: 6
Page: 4826-4835
Publish at: 2019-12-01
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