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Published By Engineering, Technology & Applied Science Research

1792-8036, 2241-4487
Updated Saturday, 16 October 2021

2021 ◽  
Vol 11 (5) ◽  
pp. 7673-7677
Author(s):  
D. N. Truong ◽  
V. T. Ngo ◽  
M. S. N. Thi ◽  
A. Q. Hoang

In this paper, the application of an Adaptive Network-based Fuzzy Inference System (ANFIS) to control a hybrid solar and wind grid-tie inverter in order to reduce power oscillations and enhance power quality is presented. To extract the maximum power from the PV system, a Perturb and Observe (P&O) algorithm is presented that tracks the Maximum Power Point (MPP). Time-domain simulation results of the studied system are performed in MATLAB/SIMULINK under different operating conditions such as changing irradiation and short-circuit faults in the power grid. From the simulation results, it can be concluded that the designed ANFIS controller and the proposed P&O algorithm perform better than the traditional PI controller and improve transient responses under severe operating conditions.


2021 ◽  
Vol 11 (5) ◽  
pp. 7653-7657
Author(s):  
P. H. V. Nguyen ◽  
P. C. Nguyen

The shaft-grouted method has been applied on high-rise buildings in Ho Chi Minh City for the purpose of increasing the bearing capacity of barrette piles. The Exim Bank Building foundation, using two kinds of shaft-grouted barrette piles, was 65m (TP1) and 85m (TP2) in depth. To assess the bearing capacity, this project assembly used the O-cell tools installed at 49m depth below the pile head level. Shaft grouting was performed from -25m to the TP1 pile toe level and -65m to the TP2 pile toe level. This work is based on the data from the O-cell experiments at the construction site and the results of finite element simulation in Plaxis software. The effectiveness of shaft grouting was analyzed and the length and position of the ejector were evaluated and compared in order to find the best solution for applying shaft grouting with the aim to ensure safety and mitigate economic problems.


2021 ◽  
Vol 11 (5) ◽  
pp. 7695-7701
Author(s):  
M. A. Zdiri ◽  
A. S. Alshammari ◽  
A. A. Alzamil ◽  
M. Ben Ammar ◽  
H. H. Abdallah

The prevalent tendency in power transmission systems is to operate closer and closer to the energy limit, rendering system voltage instability a commonly widespread phenomenon. It is, therefore, necessary that certain remedial corrective controls need be undertaken whenever these systems tend towards failure. In this respect, load shedding stands as a major correction mechanism and such a failure can be prevented and nominal system voltage can be resumed. It is worth noting however that load shedding must be implemented very carefully to ensure the satisfaction of both the customer and the electricity-production company. In this context, our focus of interest is laid on load and machine shedding against voltage collapse as an effective corrective method. It is important to note that such a problem turns out to be commonly defined as an optimization problem under constraints. Using genetic algorithms as resolution methods, the application of the proposed methods was implemented on the 14-node IEEE test network, while considering a number of different case studies.


2021 ◽  
Vol 11 (5) ◽  
pp. 7678-7683
Author(s):  
S. Nuanmeesri

Analysis of the symptoms of rose leaves can identify up to 15 different diseases. This research aims to develop Convolutional Neural Network models for classifying the diseases on rose leaves using hybrid deep learning techniques with Support Vector Machine (SVM). The developed models were based on the VGG16 architecture and early or late fusion techniques were applied to concatenate the output from a fully connected layer. The results showed that the developed models based on early fusion performed better than the developed models on either late fusion or VGG16 alone. In addition, it was found that the models using the SVM classifier had better efficiency in classifying the diseases appearing on rose leaves than the models using the softmax function classifier. In particular, a hybrid deep learning model based on early fusion and SVM, which applied the categorical hinge loss function, yielded a validation accuracy of 88.33% and a validation loss of 0.0679, which were higher than the ones of the other models. Moreover, this model was evaluated by 10-fold cross-validation with 90.26% accuracy, 90.59% precision, 92.44% recall, and 91.50% F1-score for disease classification on rose leaves.


2021 ◽  
Vol 11 (5) ◽  
pp. 7619-7623
Author(s):  
S. M. Alsaedy ◽  
N. Aljalawi

Portland cement is considered the most involved product in environmental pollution. It is responsible for about 10% of global CO2 emissions [1]. Limestone dust is a by-product of limestone plants and it is produced in thousands of tons annually as waste material. To fulfill sustainability requirements, concrete production is recommended to reduce Portland cement usage with the use of alternative or waste materials. The production of sustainable high strength concrete by using nanomaterials is one of the aims of this study. Limestone dust in 12, 16, and 20% by weight of cement replaced cement in this study. The study was divided into two parts: the first was devoted to the investigation of the best percentage of replacement of waste lime. The second part of the study evaluated the performance of concrete when adding nanomaterials. Three percentages of cement replacement 0.5%, 1%, and 1.5% with nano-Al2O3 were used. The most efficient content of hydrated lime used in this study which achieves sustainability and maintains the quality of concrete was (16%). On the other hand, it was found that the best percentage of nano-Al2O3 as a partial replacement of cement is 1.5%.


2021 ◽  
Vol 11 (5) ◽  
pp. 7605-7609
Author(s):  
. Waseemullah ◽  
M. F. Hyder ◽  
M. A. Siddiqui ◽  
M. Mukarram

Automatic TV ad detection is a challenging task in computer vision. Manual ad detection is considered a tedious job. Detecting advertisements automatically saves time and human effort. In this paper, a method is proposed for detecting repeated video segments automatically, since generally, ads appear in TV transmissions frequently. At first, the user is allowed to browse the advertisements needed to be detected, and the video in which they are to be detected. The videos are then converted into a text file using the Base64 encodings. In the third step, the advertisements are detected using string comparison methods. In the end, a report, with the names of the advertisements is shown against the total time and the number of times these advertisements appeared in the stream. The implementation was carried out in python.


2021 ◽  
Vol 11 (5) ◽  
pp. 7628-7634
Author(s):  
A. Tariq ◽  
K. L. Khatri ◽  
M. I. U. Haque ◽  
M. A. Raza ◽  
S. Ahmed ◽  
...  

The rapid increase of the electrical power demand gave rise to many challenging situations for power system control engineers as the transmission lines are operating at their maximum capacity in most developing economies. To solve this, Distributed Generation (DG), i.e. the generation of electrical power in a distribution network that provides clean energy, is gaining popularity. There are several challenges the protection of distribution networks faces after DG installation, such as variations in short circuit levels, protection blinding, reverse power flow, protection coordination, change in fault impedance, recloser-fuse coordination, selectivity, unsynchronized reclosing, false tripping, etc. In this paper, an IEEE 13-Bus System Radial Distribution System is simulated using Electrical Transient Analyzer Program (ETAP), various scenarios of DG placement are considered, their impact on the protection system is analyzed, and different techniques are proposed to minimize the effect on protection coordination. The use of directional relays, current limiting reactors, and small magnitude DGs is tested and analyzed. The way this effect varies by changing the location of DG is also analyzed.


2021 ◽  
Vol 11 (5) ◽  
pp. 7738-7744
Author(s):  
F. T. Benaissa ◽  
B. Khalfallah

Studies and research on land suitability for the localization of economic and industrial activities in cities are attracting academics and local policies concerned with urban planning and organization in order to make urban areas more accommodating. The current paper aims to demonstrate the ability of visualization and simulation techniques to assist planners in preserving urban real estate by combining the Delphi method with one of the multi-criteria hierarchical analysis decision-making techniques. The city of Bordj Bouarreridj in Algeria was chosen as the case study and, with the participation of experts, a set of criteria were adopted to determine land suitability. Three criteria were selected in the first phase with the use of the Delphi method. In the second phase, we applied the Analytical Hierarchy Process (AH, a hierarchical analysis method. During the third stage, the obtained results were translated into the GIS program to derive the spatial suitability map. The following are among the most important achieved results: 13.38% (521.793 km2) of the area was regarded to be of high suitability, 67.54% (2,634.758 km2), achieved moderate suitability, 12.94% (504,794 km2) attained low suitability, and 6.14% (239,685 km2) were found to be not suitable at all.


2021 ◽  
Vol 11 (5) ◽  
pp. 7641-7646
Author(s):  
S. A. Dahri ◽  
B. A. Memon ◽  
M. Oad ◽  
R. Bhanbhro ◽  
I. A. Rahu

This research paper presents the laboratory investigations of the compressive strength of no-fines concrete made with demolished waste as coarse aggregates used in percentages from 20% to 100%. The basic properties of aggregates were determined. Sieve analysis of both conventional and recycled aggregates was conducted to ensure the existence of well-graded aggregates in concrete. Nine concrete mixes were designed with an aggregate-cement ratio of 4. Additionally, three batches were prepared (conventional, recycled, conventional no-fines concrete) and the results were compared. For all mixes, the water-cement ratio was equal to 0.5. In each batch, 5 cylinders of standard size (total 60 samples) were prepared and cured for 28 days. The weight of the specimens was determined and compressive strength was checked in a Universal Testing Machine under gradually increasing load. A decrease in weight and compressive strength was recorded for the batches of the proposed concrete. Results show that at 40% replacement level the loss of compressive strength is 19% and the weight reduction of the samples was equal to 9%.


2021 ◽  
Vol 11 (5) ◽  
pp. 7591-7597
Author(s):  
L. Bangar Raju ◽  
K. Subba Rao

Distributed Generators (DGs) are incorporated in the power distribution systems to develop green energies in microgrids. Islanding is a challenging task in a microgrid. Different types of islanding methods, e.g. local and remote methods, have been developed for handling this task, with local methods being easier to implement, while remote methods are communication-based and costly. The local methods are classified as passive, active, and hybrid, out of which the passive methods are more simple and economical. In this paper, a passive islanding detection method is proposed to detect single line to ground fault. This fault is considered to represent the 60 to 70% of the total un-intentional faults of this category. The available passive methods cannot detect islanding at lower power mismatches as the variations in voltage and frequency fall within thresholding values. In this method, the voltage signals are first retrieved at the targeted DG output and then the phase angle is estimated. Finally, the phase angle is differentiated to get Rate Of Change Of Voltage Phase Angle (ROCOVPA) to detect islanding, and then it is compared with the Rate Of Change Of Frequency (ROCOF) at zero percent power mismatch. Simulation results depict that the ROCOVPA is more effective than ROCOF. The proposed method not only reduces detection time and Non-Detection Zone (NDZ) but is also stable during non-islanding cases like load connection and disconnection to avoid nuisance tripping.


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