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29,939 Article Results

Torque ripple minimization in direct torque control at low-speed operation using alternate switching technique

10.11591/ijpeds.v13.i1.pp631-642
Muhammad Zaid Aihsan , Auzani Jidin , Azrita Alias , Siti Azura Ahmad Tarusan , Zuraidi Md Tahir , Tole Sutikno
Direct torque control (DTC) of induction motor is prominent to offer instant torque and flux control with a simple control structure. However, this scheme suffers from two major drawbacks namely high torque ripple and variable switching frequency of the inverter, especially during low-speed operation. During the low-speed condition, the positive torque slope is very steep and torque overshoot occurs frequently resulting in the torque ripple become of great significance. This paper proposes a new and effective technique to reduce the torque ripple by integrating the alternate switching technique to the inverter switching status to limit the torque slope surge. By varying the frequency and duty cycle of the alternate switching, the rate of surge can be controlled resulting in the chances of overshoots, and selection of reverse voltage vector can be avoided. The feasibility of the proposed technique has been validated using MATLAB/Simulink software and through experimental results. The results show the proposed alternate switching technique minimizes over 40% reduction in the torque ripple while maintaining the simple structure of DTC.
Volume: 13
Issue: 1
Page: 631-642
Publish at: 2022-03-01

Maternal health services utilization and its contributing factors among adolescent mothers

10.11591/ijphs.v11i1.21041
Dewi Nuryana , Pramon Viwattanakulvanid , Nohan Arum Romadlona
Adolescent girls (15-19 years old) experienced childbirth face the higher risk for maternal mortality than older women. This study aimed to assess the utilization level of maternal health services and to identify factors that contribute to the maternal health services utilization in Indonesian adolescent mothers. The study used secondary data from 2017 Indonesia Demographic and Health Survey (IDHS) and included women who had last birth at the age of 15-19 years old which total is 866 women. Among adolescent mothers, the highest level of utilization is post-natal care (PNC) (71.5%) followed by antenatal care (ANC) (67.2%) then delivery services (64.5%). Factors that associated with ANC utilization are husband/partner’s education, mother’s autonomy, region, husband accompanied during ANC, topic discussed during ANC, and intendedness of last birth (p<0.05). Factors contributed to delivery services are mother’s education, mother’s working status, mother’s autonomy, residence, region, wealth index, health insurance, husband accompanied during ANC, and topic discussed during ANC (p<0.05). Whereas, for PNC utilization are knowledge of danger sign during childbirth, residence, region, and delivery services utilization (p<0.05). Therefore, health strategic programs which focused on adolescent mothers are necessary to improve the maternal health in Indonesia.
Volume: 11
Issue: 1
Page: 77-87
Publish at: 2022-03-01

Critical thinking skills: Error identifications on students’ with APOS theory

10.11591/ijere.v11i1.21171
Khoerul Umam , Ardi Dwi Susandi
Identifying students' errors in solving cases of critical thinking skills from two variables of linear equation (TVLE). This was a qualitative study using a descriptive exploratory approach. The participants of the study were first-year students of mathematics education. The method used in this research is a test, interview, and triangulation. The findings showed that the students have low critical thinking skills; therefore, they could not complete the task correctly. Based on the Action-Process-Object-Schema (APOS) theory, students' mistakes in completing math problems consist of four elements, namely: i) The errors in interpreting; ii) The errors in understanding the concept; iii) The error in the procedures; and iv) The error in technical things. The student's response in this study was in the theoretical of APOS, so that they could not reach a correct schema. The study results are expected to be beneficial in developing the activities in teaching TVLE, so that the students will make less errors in completing critical thinking skills problems in mathematics. Therefore, further study in developing a teaching model for mathematics teaching to improve students' critical thinking skills is highly recommended.
Volume: 11
Issue: 1
Page: 182-192
Publish at: 2022-03-01

AraBERT transformer model for Arabic comments and reviews analysis

10.11591/ijai.v11.i1.pp379-387
Hicham EL Moubtahij , Hajar Abdelali , El Bachir Tazi
Arabic language is rich and complex in terms of word morphology compared to other Latin languages. Recently, natural language processing (NLP) field emerges with many researches targeting Arabic language understanding (ALU). In this context, this work presents our developed approach based on the Arabic bidirectional encoder representations from transformers (AraBERT) model where the main required steps are presented in detail. We started by the input text pre-processing, which is, then, segmented using the Farasa segmentation technique. In the next step, the AraBERT model is implemented with the pertinent parameters. The performance of our approach has been evaluated using the ARev dataset which contains more than 40,000 comments-remarks records relate to the tourism sector such as hotel reviews, restaurant reviews and others. Moreover, the obtained results are deeply compared with other relevant states of the art methods, and it shows the competitiveness of our approach that gives important results that can serve as a guide for further improvements in this field.
Volume: 11
Issue: 1
Page: 379-387
Publish at: 2022-03-01

Emergency congestion management of power systems by static synchronous series compensator

10.11591/ijeecs.v25.i3.pp1258-1265
Majeed Rashid Zaidan , Saber Izadpanah Toos
From a transmission system point of view, any overload on the grid lines during operation in situations such as peak load or emergency conditions include line outage or generator outage, is refers to congestion. Generally, the congestion can be managed by controlling power flow. On the other hand, series compensation has a significant role in control power flow; therefore, series compensation equipment like fixed series capacitor (FSC), thyristor-controlled series capacitor (TCSC), and static synchronous series compensator (SSSC) can be used for congestion management. In this paper, an SSSC is used in a transmission line to manage congestion in emergency conditions, line outage and generator outage. The congestion rent contribution method has been used to determine the location of the SSSC in the IEEE 14-bus test system. This technique finds the transmission line 1-2 (from bus 1 to bus 2) is the best location of the SSSC to reduce congestion. After installing an SSSC in the specified line, simulation results show that the power flow has been controlled, leading to reducing the congestion. In other words, the effectiveness of the SSSC can be seen in reducing the total congestion rent, the total generation cost, and network losses.
Volume: 25
Issue: 3
Page: 1258-1265
Publish at: 2022-03-01

Optimal economic dispatch using particle swarm optimization in Sulselrabar system

10.11591/ijai.v11.i1.pp221-228
Marhatang Marhatang , Muhammad Ruswandi Djalal
In this study, a particle swarm optimization (PSO) is proposed to optimize the cost of generating thermal plants in the South Sulawesi system. The study was con ducted by analyzing several methods using the lagrange and ant colony optimization (ACO). PSO algorithm converges on the 11th iteration algorithm with the lowest generation cost obtained, which is Rp129687962.17/hour. While the ACO algorithm converges on the 34th iteration with a generation cost of Rp131,473,269.39/hour. The results of optimization using PSO produce a total thermal power of 400.75 MW and losses of 26.15 MW. The PSO method is able to reduce the cost of generating the South Sulawesi system by Rp11,118,312.07/hour or 7.9%. While using the ACO method generates a generation cost of Rp131,473,269.39/hour to generate power of 400,812 MW with losses of 26,219 MW. The ACO method is able to reduce the cost of generating the South Sulawesi system by Rp9,333,004.9/hour or 6.62%. PSO algorithm provides the lowest cost calculation of generator compared with conventional methods and ACO smart methods. This is also shown in the calculation process, the PSO method completes calculations faster than the ACO method.
Volume: 11
Issue: 1
Page: 221-228
Publish at: 2022-03-01

Influence of non-sinusoidal power supply on the performance of a single-phase capacitor induction motor

10.11591/ijeecs.v25.i3.pp1246-1257
Omar Sharaf Al-deen Alyozbaky , Mohd Zainal Abidin Ab‐Kadir
Harmonic is seen to be an important factor that can influence the performance of different electrical appliances. Earlier studies have regarded the non-sinusoidal power supply as the major source of the harmonic in the induction motors. In this paper, the researcher compared the results generated by a single-phase capacitor induction motor (SIM) using the sinusoidal and non-sinusoidal power supplies. The results in the study could help in comprehensively understanding the impact of the harmonic on the effective performance of the SIM machines when they were powered using a non-sinusoidal power supply. Here, the performance of the SIM when subjected to a maximum load or non-load condition were studied and determined. Furthermore, numerous experimental work was presented to validate the results of the SIM. Power analyses and spectral analysis indicated the actual difference in the overall harmonic wave distortion. It was seen that the current load increased to 89% (i.e., an increase of 11%) when the motor working from the non-sinusoidal source. This investigation highlighted the direct impact of the non-sinusoidal power source on the properties and components of the SIM machine. The vibrations measured under varying conditions and compared the results for the 2 types of power supplies.
Volume: 25
Issue: 3
Page: 1246-1257
Publish at: 2022-03-01

Impact of on-grid solar energy generation system on low voltage ride through capability

10.11591/ijpeds.v13.i1.pp488-499
Mohammad Ahmad Shawqi , Mokhtar Hussien Abdallah , Ibrahim Ahmed Nassar
This paper represented a control strategy for photovoltaic (PV) system, this control strategy was referred to as a low voltage ride through (LVRT), it had been achieved by using three phase (3-PH) (PV) grid-connected system, where this paper discussed the way to achieve maximum output active power from the solar system, while the solar system remained connected to the grid with voltage decreasing controller techniques and this was valid until certain amount of voltage decreasing which was clarified in the results. The main goal of low voltage ride through depended on injecting reactive power to the grid, amount of the injected reactive power depended on regulations of the grid code using the control of the inverter and the strategy depended on the grid voltage drop amount. MATLAB simulation had been used to achieve what was mentioned above, which led to present various cases of achieving maximum output active power with grid voltage drops by using conventional proportional integral (PI) control of the inverter. Finally, another control method, which was proportional integral genetic algorithm (PI-GA), had been used to improve value of the generated output active power.
Volume: 13
Issue: 1
Page: 488-499
Publish at: 2022-03-01

Fault detection and power quality analysis of wind turbine system using integrated systems

10.11591/ijpeds.v13.i1.pp576-585
Anburaj Mutharasan , Perumal Chandrasekar
Growth in the need for electric energy and fossil fuel scarcity endorses renewable energy generation sources. The generation cost of electric power utilizing wind turbines is cost-effective and straightforward compared to other renewable energy sources (RES). Recently, hasty research and developments have been presented in wind turbines (WT) by researchers globally. Although wind-based energy production is more content, planting the WT is challenging. Maintaining the WT from fault incidence is highly crucial. The fault in the WT distresses the power quality of the produced energy. This condensed power quality affects the transmission systems, substations, and loading end of the renewable source. Also, gear malfunctioning is the primary reason for most of the downtime in wind turbines. This work successfully proposed and implemented a deoxyribonucleic acid (DNA) sequencing-based control technique to reduce the drive train vibration. Therefore, fault detection and monitoring in WTs play an active part in power production and quality maintenance. In this work, a vibration-grounded WT gearbox fault observing scheme is proposed to increase the power quality. Precisely, a wavelet is executed to chart the vibration gesture. Also, the current sensor gesture is implemented to discover the power quality variances associated with the WT's vibration magnitude.
Volume: 13
Issue: 1
Page: 576-585
Publish at: 2022-03-01

Image and video face retrieval with query image using convolutional neural network features

10.11591/ijai.v11.i1.pp102-109
Imane Hachchane , Abdelmajid Badri , Aïcha Sahel , Ilham Elmourabit , Yassine Ruichek
This paper addresses the issue of image and video face retrieval. The aim of this work is to be able to retrieve images and/or videos of specific person from a dataset of images and videos if we have a query image of that person. The methods proposed so far either focus on images or videos and use hand crafted features. In this work we built an end-to-end pipeline for both image and video face retrieval where we use convolutional neural network (CNN) features from an off-line feature extractor. And we exploit the object proposals learned by a region proposal network (RPN) in the online filtering and re-ranking steps. Moreover, we study the impact of finetuning the networks, the impact of sum-pooling and max-pooling, and the impact of different similarity metrics. The results that we were able to achieve are very promising.
Volume: 11
Issue: 1
Page: 102-109
Publish at: 2022-03-01

Design of semi-Z source inverter topology with reduced number switches for four quadrant control of direct current motor

10.11591/ijpeds.v13.i1.pp102-112
Waseah Anjum , Sudeekshya Panda , Palanisamy Ramasamy
This paper proposes a novel approach to 4-quadrant speed control of a direct current (DC) motor based on the use of a semi-Z source inverter which has 2 active switches and 2 switching states. The semi-Z source inverter topology is analyzed for design purposes and results and relationships are discussed. The objective of this simulation is to design and analyze the performance of closed loop speed control of a DC motor using a semi-Z source inverter under realistic operating conditions. The findings of this project can be useful for designing several household appliances as well as systems like lathe machines, hoists, conveyors, and fans. Closed loop system designed for automatic speed control of a DC motor is obtained by using MATLAB/Simulink. The simulation results show that the proposed system works as intended.
Volume: 13
Issue: 1
Page: 102-112
Publish at: 2022-03-01

Algorithm fuzzy scheduling for realtime jobs on multiprocessor systems

10.11591/ijeecs.v25.i3.pp1308-1319
Nirmala Holagundi , Girijamma Hollalkere Ashwathsetty , Mustafa Basthikodi
The computing in Real-time is rapidly focusing much developments in technologies so that the real-time jobs are to be scheduled and executed on computing systems in particular time frame. The scheduling and load balancing techniques in distributed systems face numerous challenges because of lack of centralized strategy to dispatch the jobs in multiprocessors systems. In this work, we propose an Algorithm Fuzzy Scheduling (AFS) for real-time jobs that includes of Arrival time, Deadline and Computation time as the scheduling parameters of input. The approach AFS is analyzed and compared with Existing Fuzzy Algorithm (EFA) model for evaluation of performances from the outcome of the simulation. The jobs are scheduled on multiprocessor at higher system load by making use of fuzzy mechanisms in the algorithms. The experimental results prove that the proposed AFS achieves a better performance comparatively to EFA at various system load factors with respect to mean turnaroundtime, mean response time and count of missed deadlines. This is the initial phase of the algorithm, that will be enhanced to consider a greater number of parameters to be associated with jobs for better decision making and to investigate the scope for algorithm level parallelism.
Volume: 25
Issue: 3
Page: 1308-1319
Publish at: 2022-03-01

Comparative study of extraction features and regression algorithms for predicting drought rates

10.12928/telkomnika.v20i3.23156
Irza Hartiantio; Mercu Buana University Rahmana , Amalia Rizki; Mercu Buana University Febriyani , Indra; Mercu Buana University Ranggadara , Suhendra; Mercu Buana University Suhendra , Inna; Mercu Buana University Sabily Karima
Rice is the primary staple food source for Indonesian people, with consumption increasing so that rice production needs to be increased. Rice drought is one of the problems that can hamper rice production. This research aims to determine the best extraction feature between the normalized difference vegetation index (NDVI) and the normalized difference water index (NDWI) in describing rice fields’ dryness. Moreover, using the random forest regression algorithm. This research compares NDVI with NDWI using data originating from Sentinel-2A and retrieved via the google earth engine. Regression algorithms are used in research to predict drought in paddy fields. This research shows that NDVI is better than NDWI in predicting drought using random forest regression algorithms and logistic regression algorithms. The random forest regression algorithm based on the results obtained shows that the average root mean square error (RMSE) on NDVI is 0.018, and NDWI is 0.012. Based on the logistic regression algorithm results, it was found that the average value of RMSE on NDVI was 0.346, and NDWI was 0.336. Based on the results of the RMSE, it shows that the forecasting ability of the random forest regression algorithm is better than the logistic regression.
Volume: 20
Issue: 3
Page: 638-646
Publish at: 2022-03-01

Development of a new linearizing controller using Lyapunov stability theory and model reference control

10.11591/ijeecs.v25.i3.pp1328-1343
Yohan Darcy Mfoumboulou , Mkhululi Elvis Siyanda Mnguni
One of the most challenging aspects in the nonlinear control of a magnetic levitation (Maglev) system is to find an efficient control algorithm to achieve the stability and accuracy of the closed-loop system. The challenge is then to develop a linearizing control algorithm to maintain a steel ball at a desired position. In this paper, a novel linearizing control algorithm is proposed, which consists of the Lyapunov direct method (LDM) and the model reference control (MRC). The Lyapunov function is developed using the nonlinear equations of the magnetic levitation system, and the reference model is a linear second order system. Two control methods are developed to guarantee system robustness and output stability. Firstly, a new integral linear quadratic regulator (ILQR) is designed for the reference model. Then, an additional innovative proportional gain is combined with the linearizing controller to make the nonlinear control signal stronger. The simulation results indicate that the proposed linearizing controller has excellent set-point tracking, no time delay, fast rising and settling times, and achieves states stability.
Volume: 25
Issue: 3
Page: 1328-1343
Publish at: 2022-03-01

Group investigation model to improve interpersonal skills

10.11591/ijere.v11i1.21914
Nur Ainiyah , Anik Ghufron , Marzuki Marzuki , Said Subhan Posangi , Kasim Yahiji , Abdul Rohman , Moch. Tolchah , St. Wardah Hanafie Das
This study aimed to prove the effectiveness of the application of the group investigation learning model in improving students' interpersonal skills. The sample of this study was 116 students, which was determined by a simple random sampling technique. This experimental research used pre-test post-test Control Group Design. Data were obtained by direct observation of the interpersonal skills of students during the learning process. Final observation score of interpersonal skills is 0.026 and the t value count greater than t table (2.272>1.980). Thus, there are differences in interpersonal skills between the experimental class and the control class. This means that the use of the group investigation model is effective in improving students' interpersonal skills.
Volume: 11
Issue: 1
Page: 467-474
Publish at: 2022-03-01
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