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31,456 Article Results

Experimental installation of wireless power transfer system based on the series resonance technology

10.11591/ijpeds.v11.i4.pp1693-1700
Sarab Al-Chlaihawi , Adnan Hasan Tawafan , Fatima Kadhem Abd
In this work, we aim to install a wireless power transfer (WPT) system experimentally. Series resonance technology was used to achieve zero-voltage switching (ZVS). We investigated the impact of the primary and secondary resonance frequencies (fp and fd), and inverter frequency switching (fch) on the efficiency (β) and maximum transfer power in a WPT system based on the inductive wireless power transfer (IWPT) technology. An ultrasonic device was utilized as a generator to excite the coil at the primary side. The experimental outcomes showed that there is an optimum unlike fp and fd can be got to match fch. It was found also that there is a trade-off between the power supplied to the load (PRL) and DC-DC efficiency (β). At an air-gap of 5 cm, the obtained results are recorded as follows; the peak recorded system β is 62% that was obtained at fp=19 kHz, fd=fch=24 kHz that is corresponding to 101.88W of PRL; whereas the highest PRL resulted i.e. 244W when fp=19 kHz, fd =24 kHz, fch=21 kHz at 61% of β; in such case, the maximum β* PRL multiplication was achieved i.e. 149. Moreover, the coils’ misalignment was studied. The outcomes showed that the lateral misalignment has worst effect on the PRL and β than the air-gap. The experimental results were validated with simulation ones.
Volume: 11
Issue: 4
Page: 1693-1700
Publish at: 2020-12-01

Innovations into industrial technology programmes of Nigerian Universities for effective application of mobile communication technologies and quality assurance of graduates

10.11591/ijeecs.v20.i3.pp1315-1324
Jimoh Bakare , Hyginus Osita Omeje , Samson Oluwatimilehin , Samson Ikenna Nwaodo , Obe Pauline Ijeoma , Olusesan Johnson Ogunmilade , Ojo Ajiboye Olaoye
The study innovated the industrial technology programmes of Nigerian Universities for effective application of mobile communication technologies and quality assurance of graduates. Five research questions guided the study while three null hypotheses formulated were tested at .05 level of significance. The study made use of descriptive survey design and was carried out in Enugu State, Nigeria.nThe participants for the study were 120 comprising of 67 lecturers ofmelectrical/electronic technology and 53 technologists of industrial technical education. A 97-item questionnaire was used as instrument for data collection. One hundred and eighteen copies of the questionnaire were retrieved. The data collected were analyzed using mean, factor analysis, standard deviation and improvement need index (INI) to answer the four research questions while analysis of variance was employed to test the hypotheses at .05 level of significance. Results revealed that 33 innovations for inclusion into programme of electrical/electronic technology. Furthermore, the results of the study revealed that teachers need improvement in implementing the innovated contents of electrical/electronic technology aspect of industrial technical education programme. Hence, there is need to package the findings of the study into training programme and use it for building the capacity of teachers of electrical/electronic technology in Nigerian universities.
Volume: 20
Issue: 3
Page: 1315-1324
Publish at: 2020-12-01

A high-performance multilevel inverter with reduced power electronic devices

10.11591/ijpeds.v11.i4.pp1883-1889
Amer Chlaihawi , Adnan Sabbar , Hur Jedi
This paper introduces a new topology of multilevel inverter, which is able to operate at high performance. This proposed circuit achieves requirements of reduced number of switches, gate-drive circuits, and high design flexibility. In most cases fifteen-level inverters need at least twelve switches. The proposed topology has only ten switches. The inverter has a quasi-sine output voltage, which is formed by level generator and polarity changer to produce the desired voltage and current waveforms. The detailed operation of the proposed inverter is explained. The theoretical analysis and design procedure are given. Simulation results are presented to confirm the analytical approach of the proposed circuit. A 15-level and 31-level multilevel inverters were designed and tested at 50 Hz.
Volume: 11
Issue: 4
Page: 1883-1889
Publish at: 2020-12-01

Analysis on EMF characteristics for torque ripple reduction in BLAC motor intended for HVLS fan application

10.11591/ijpeds.v11.i4.pp2203-2211
Nurfaezah Abdullah , Raja Nor Firdaus Raja Othman , Kasrul Abdul Karim , Lim Seng Tat
This paper analyzes the harmonic characteristics of electromagnetic force (EMF) in Brushless Alternating Current (BLAC) motor for High Volume Low Speed (HVLS) fan application. Vibration and noise are one of the main crucial things in HVLS fan application. It comes from torque ripples which can be detected by harmonics of Electro Magnetic Force (EMF). Commonly, there are a few methods to eliminate the noise and vibrations issue, but most literatures only focus on small motor and not intended for HVLS fan application. Thus, the objective of this paper is to eliminate the harmonics content in EMF at early stage design. Through EMF harmonics the expected torque produced could be used to select proper slot-pole number in order to eliminate the noise and vibrations issue. In here, the analysis involves three different slot-pole numbers which are 18s/20p, 12s/10p and 9s/8p BLAC model, respectively. All models have similar volume of permanent magnet. The analysis is carried out using FLUX 2D Finite Element Analysis (FEA) for EMF computational and transient torque computation. Later, Fast Fourier Transform (FFT) analysis is used to calculate the harmonics of EMF. The analysis stage includes the EMF parameter analysis, harmonics and torque ripples analysis. It was found that 18s/20p has higher output torque with the lowest 5% torque ripple value. As a conclusion, this paper presents low torque ripple in point of view of the EMF characteristics in designing HVLS fan.
Volume: 11
Issue: 4
Page: 2203-2211
Publish at: 2020-12-01

A new hybrid algorithm for solving distribution network reconfiguration under different load conditions

10.11591/ijeecs.v20.i3.pp1118-1127
Omar Muhammed Neda
Distribution network reconfiguration (DNR) is a significant problem for keeping the network running under normal conditions. In this study, for preventing the premature convergence issue, also to improving the searching ability of the binary particle sarm optimization (BPSO) algorithm, chaotic strategy is incorporating with BPSO algorithm to create a new hybrid algorithm called chaotic BPSO (CBPSO). Undeniably, the chaotic strategy enables the hybrid CBPSO algorithm to slip from the local optima and also to reach optimal solution in fewer number of iterations compare to BPSO due to the remarkable behavior and ergodic of the chaos strategy than random search in BPSO algorithm. The CBPSO algorithm is presented as a advantageous optimization tool for solving DNR. In this problem, decreasing of real power loss () is an objective function while node voltage, system radially and line current have been utilized as a constrains of the system. The search space in this problem for the presented technique is a group of lines (switches) that are normally opened or closed. Two types of loads are presented: the constant and variable loads for testing the efficacy of the CBPSO method for tackling DNR problem when the load is changes. The proposed technique is implemented on IEEE Node system by utilizing R2013b software for verifying the efficacy of CBPSO technique. The simulation results confirm that technique has high ability in reducing and raising the voltage profile of the grid compared to and other procedures in the literature.
Volume: 20
Issue: 3
Page: 1118-1127
Publish at: 2020-12-01

Modeling of battery pack sizing for electric vehicles

10.11591/ijpeds.v11.i4.pp1987-1994
V. Sandeep , Suchitra Shastri , Arghya Sardar , Surender Reddy Salkuti
The paper presents the mathematical modeling for battery pack sizing to evaluate the vehicle energy consumption by using the derivation from Parametric Analytical Model of Vehicle Energy Consumption (PAMVEC) by Simpson in R Studio. The assess of storage batteries for electric vehicles (EVs) application is presented in this paper. The main source of power in EVs are batteries and to properly optimize their use in them, a parametric vehicle dynamic model is created and factors like battery mass, energy needed for the EV etc. are predicted using inputs such as battery specific energy, range etc. An assessment of output parameters is performed by using different batteries and compared to determine best battery for EV application.
Volume: 11
Issue: 4
Page: 1987-1994
Publish at: 2020-12-01

An enhanced 17-level hybridized multilevel inverter with stair case modulation

10.11591/ijpeds.v11.i4.pp1872-1882
Hemalatha Javvaji , Basavaraja Banakara
This paper proposes a Hybridized Symmetric Cascaded Multilevel Inverter for voltage levels ranging from 5 levels to 17 levels. The proposed Multi Level Inverter (MLI) topology is built using a modified H-bridge inverter that results in an increased output voltage levels with a smaller number of solid-state switches. This technique enhances the h-bridge configuration from three level to five level by means of a bi-directional switch at source. Gating pulses of hybridized symmetric MLI are generated through staircase modulation. The operation and performance of the proposed topology is tested for different output voltage levels, simulation results prove that the proposed technique results in less THD at all levels with lesser power consumption and are easily applicable for renewable energy applications.
Volume: 11
Issue: 4
Page: 1872-1882
Publish at: 2020-12-01

Automated server-side model for recognition of security vulnerabilities in scripting languages

10.11591/ijece.v10i6.pp6061-6070
Rabab F. Abdel-Kader , Mona Nashaat , Mohamed I. Habib , Hani M. K. Mahdi
With the increase of global accessibility of web applications, maintaining a reasonable security level for both user data and server resources has become an extremely challenging issue. Therefore, static code analysis systems can help web developers to reduce time and cost. In this paper, a new static analysis model is proposed. This model is designed to discover the security problems in scripting languages. The proposed model is implemented in a prototype SCAT, which is a static code analysis Tool. SCAT applies the phases of the proposed model to catch security vulnerabilities in PHP 5.3. Empirical results attest that the proposed prototype is feasible and is able to contribute to the security of real-world web applications. SCAT managed to detect 94% of security vulnerabilities found in the testing benchmarks; this clearly indicates that the proposed model is able to provide an effective solution to complicated web systems by offering benefits of securing private data for users and maintaining web application stability for web applications providers.
Volume: 10
Issue: 6
Page: 6061-6070
Publish at: 2020-12-01

Powerful processing to three-dimensional facial recognition using triple information

10.11591/ijaas.v9.i4.pp326-332
Mohammad Karimi Moridani , Ahad Karimi Moridani , Mahin Gholipour
Face Detection plays a crucial role in identifying individuals and criminals in Security, surveillance, and footwork control systems. Face Recognition in the human is superb, and pictures can be easily identified even after years of separation. These abilities also apply to changes in a facial expression such as age, glasses, beard, or little change in the face. This method is based on 150 three-dimensional images using the Bosphorus database of a high range laser scanner in a Bogaziçi University in Turkey. This paper presents powerful processing for face recognition based on a combination of the salient information and features of the face, such as eyes and nose, for the detection of three-dimensional figures identified through analysis of surface curvature. The Trinity of the nose and two eyes were selected for applying principal component analysis algorithm and support vector machine to revealing and classification the difference between face and non-face. The results with different facial expressions and extracted from different angles have indicated the efficiency of our powerful processing.
Volume: 9
Issue: 4
Page: 326-332
Publish at: 2020-12-01

Wireless charging system for electric bicycle application

10.11591/ijpeds.v11.i4.pp1926-1935
Nguyen Thi Diep , Nguyen Kien Trung , Tran Trong Minh
This paper presents a design of the wireless charging system for e-byke applications. The double-side LCC compensation circuit is used to achieve high efficiency and reduce the volt-ampere rating. A new constant current/voltage (CC/CV) charging control method at the transmitter side is proposed to avoid dual side wireless communication. This paper also presents a simple method of estimating both the coupling coefficient and load impedance only from the transmitter side. A wireless charging system of 2.5kW is built. Error in the CC/CV charging mode is 3.3% and 1.12%, respectively. System efficiency reaches 92.1% in CC charging mode.
Volume: 11
Issue: 4
Page: 1926-1935
Publish at: 2020-12-01

Discrete and continuous model of three-phase linear induction motors considering attraction force and end-effects

10.11591/ijpeds.v11.i4.pp1737-1749
Nicolás Toro-García , Yeison Alberto Garcés-Gómez , Fredy E. Hoyos
The continuous model of the linear induction motor (LIM) has been made considering the edge effects and the attraction force. Taking the attraction force into account is im- portant when considering dynamic analysis when the motor operates under mechanical load. A laboratory prototype has been implemented from which the parameters of the equivalent LIM circuit have been obtained. The discrete model has been developed to quickly obtain computational solutions and to analyze non-linear behaviors through the application of discrete control systems. In order to obtain the discrete model of the LIM we have started from the solution of the continuous model. To develop the model, the magnetizing inductance has been considered, which reflects the edge effects. In the results, the model is compared without considering the edge effects or the attraction force with the proposed model.
Volume: 11
Issue: 4
Page: 1737-1749
Publish at: 2020-12-01

Improvement of the performance of STATCOM in terms of voltage profile using ANN controller

10.11591/ijpeds.v11.i4.pp1966-1978
Mohammed Salheen Alatshan , Ibrahim Alhamrouni , Tole Sutikno , Awang Jusoh
The electronic equipments are extremely sensitive to variation in electric supply. The increasing of a nonlinear system with several interconnected unpredicted and non-linear loads are causing some problems to the power system. The major problem facing the power system is power quality, controlling of reactive power and voltage drop. A static synchronous compensator (STATCOM) is an important device commonly used for compensation purposes, it can provide reactive support to a bus to compensate voltage level. In this paper, the Artificial Neural Network (ANN) controlled STATCOM has been designed to replace the conventional PI controller to enhance the STATCOM performance. The ANN controller is proposed due to its simple structure, adaptability, robustness, considering the power grid non linearities. The ANN is trained offline using data from the PI controller. The performance of STATCOM with case of Load increasing and three-phase faults case was analyzed using MATLAB/Simulink software on the IEEE 14-bus system. The comprehensive result of the PI and ANN controllers has demonstrated the effectiveness of the proposed ANN controller in enhancing the STATCOM performance for Voltage profile at different operating conditions. Furthermore, it has produced better results than the conventional PI controller.
Volume: 11
Issue: 4
Page: 1966-1978
Publish at: 2020-12-01

Developing an assessment framework of multidimensional scientific competencies

10.11591/ijere.v9i4.20542
Sasima Intasoi , Putcharee Junpeng , Keow Ngang Tang , Jatuphum Ketchatturat , Yidan Zhang , Mark Wilson
The study aimed to develop and validate an assessment framework of multidimensional scientific competencies for seventh-grade students in the northeastern region of Thailand. A total of 289 samples with three different scientific competency levels were randomly selected to participate as testtakers. The design-based research encompassing four phases of the construct modelling approach, namely construct maps, item design, outcome space, and Wright map. Multidimensional Random Coefficient Multinomial Logit model was employed to examine the quality of the created assessment framework of multidimensional scientific competencies. The results showed that scientific competence is comprised of three dimensions, namely explain phenomena scientifically, evaluate and design scientific inquiry, and interpret data and evidence scientifically. Each dimension can be further categorized into four levels. The assessment framework consists of 16 items. The results revealed that there is validity evidence regarding internal structure based on the comparison of the model fit and Wright map. Moreover, results also indicated that the reliability evidence and item fit are compliance with the quality of the assessment framework as revealed in the analysis of standard error of measurement and infit and outfit of the items. It can be concluded that the assessment framework is currently prevalent to assess the scientific competencies of seventh-grade students.
Volume: 9
Issue: 4
Page: 963-970
Publish at: 2020-12-01

Outlier detection in WSN by entropy based machine learning approach

10.11591/ijeecs.v20.i3.pp1435-1443
Manmohan Singh Yadav , Shish Ahamad
Environmental disasters like flooding, earthquake, epidemics etc. cause’s significant catastrophic effects on population of all over the world. Wireless sensor network (WSN) based techniques have become significantly popular in susceptibility modelling of such challenging disaster due to their greater strength and efficiency in the prediction of such threats occurring enormously day by day. This paper demonstrates the multiple machine learning-based approach to predict outlier in sensor data records with the use of bagging, boosting, random subspace, SVM and KNN based frameworks for outlier prediction using a Wireless sensor network data records. First of all the algorithm follows the pre processing of the database taken from records of 14 sensor motes with presence of outlier due to intrusion. Subsequently the segmented database is created from sensor pairs. Finally, the data entropy is calculated and used as a feature to determine the presence of outlier used different approach. Results show that the KNN model has the highest prediction capability for outlier assessment.
Volume: 20
Issue: 3
Page: 1435-1443
Publish at: 2020-12-01

Teachers’ strategies on teaching grammar: Facts and expectations of senior high school teachers at Ambon

10.11591/ijere.v9i4.20643
Threesje Roza Souisa , Lelyemin Yanuarius
This study is aimed at describing the English as a Foreign Language (EFL) senior high schools’ teachers’ perceptions on grammar teaching; their teaching strategies which are the most and less frequently applied in their classroom practices and the challenges that they have in teaching grammar. Explanatory mixed approaches were conducted involving 63 teachers as the sample population in collecting quantitative data, and five selected teachers as participants for collecting the qualitative data. The findings showed that teachers' perceptions of grammar teaching are based on their conceptual knowledge as they have experienced it and it is based on grammar theories. The teachers applied vary grammar approaches and strategies but they still face with the challenges in teaching grammar such as students' learning styles and less of teaching references.
Volume: 9
Issue: 4
Page: 1121-1127
Publish at: 2020-12-01
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