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1.
Heliyon ; 8(12): e12049, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36531618

ABSTRACT

This study presents a practical computer-based design program for a power cable network called "Power Cables Graphical User Interface" (PCGUI). This program is mainly for academic education, consulting electrical designers, primary engineers, and technical personnel with open-source code and a simple user interface. As a low/medium-voltage cable selection program, PCGUI will represent an essential part of the design for any electrical system, including different and complex analytic procedures based on various international standards ("IEEE, IEC, BS, NEC, NPFA 70, and local applied country standards."). A MATLAB PCGUI program gives a new method to analyze and identify the optimized cable design depending on huge numbers of MATLAB script files and data appropriate for different factors and conditions. These factors and conditions include the type of insulation, temperature factor, grouping factor, accepted voltage drop, cable lifetime costs, etc. PCGUI is easily accomplished with the least effort and provides a fast and economical design with very high accuracy through limited manual input steps. After executing the program, the obtained results will contain the complete economic cable design, the circuit breaker standard rating and type, the actual cable current loading, the actual voltage drop, and the primary and the most economic cable cross-section area "CSA" based on the cost analysis.

2.
Sensors (Basel) ; 22(4)2022 Feb 19.
Article in English | MEDLINE | ID: mdl-35214536

ABSTRACT

This paper presents the results of research and development of capacitive-based sensors of rotating shaft vibration for fault diagnostic systems of powerful turbines and hydro generators. It showed that diagnostic systems with special sensors are the key to increasing the reliability of powerful turbines and hydro generators. The application of sensors in monitoring systems was considered, and the requirements for the sensors used were analyzed. Structures of concentric capacitive-based sensors of rotating shaft vibration based on the measurement of the capacitance value from the distance to the metal surface were proposed. The design scheme was created for determining electrode dimensions of the rotating shaft vibration capacitive-based sensors with concentric electrodes, and analytical dependences were obtained. The calculation results allow the selection of optimal parameters of the active and guard electrodes. Analytical and computer simulation methods determined the response functions of the capacitive sensors. Analytical calculations and simulation results using 3D FEM were used to find the response functions of the sensors. The calculation of the characteristics of the capacitive-based sensors of rotating shaft vibration is presented. The study of the influence of fringe effects was carried out using the obtained results of the modeling and analytical calculations.

3.
PeerJ Comput Sci ; 7: e682, 2021.
Article in English | MEDLINE | ID: mdl-34541310

ABSTRACT

In this study, a deep learning bidirectional long short-term memory (BiLSTM) recurrent neural network-based channel state information estimator is proposed for 5G orthogonal frequency-division multiplexing systems. The proposed estimator is a pilot-dependent estimator and follows the online learning approach in the training phase and the offline approach in the practical implementation phase. The estimator does not deal with complete a priori certainty for channels' statistics and attains superior performance in the presence of a limited number of pilots. A comparative study is conducted using three classification layers that use loss functions: mean absolute error, cross entropy function for kth mutually exclusive classes and sum of squared of the errors. The Adam, RMSProp, SGdm, and Adadelat optimisation algorithms are used to evaluate the performance of the proposed estimator using each classification layer. In terms of symbol error rate and accuracy metrics, the proposed estimator outperforms long short-term memory (LSTM) neural network-based channel state information, least squares and minimum mean square error estimators under different simulation conditions. The computational and training time complexities for deep learning BiLSTM- and LSTM-based estimators are provided. Given that the proposed estimator relies on the deep learning neural network approach, where it can analyse massive data, recognise statistical dependencies and characteristics, develop relationships between features and generalise the accrued knowledge for new datasets that it has not seen before, the approach is promising for any 5G and beyond communication system.

4.
Materials (Basel) ; 14(9)2021 May 01.
Article in English | MEDLINE | ID: mdl-34062877

ABSTRACT

The use of corrugated webs increases web shear stability and eliminates the need for transverse stiffeners in steel beams. Optimised regression learner techniques (ORLTs) are rarely used for calculating shear capacity in steel beam research. This study proposes a new approach for calculating the maximum shear capacity of steel beams with trapezoidal corrugated webs (SBCWs) by using ORLTs. A new shear model is proposed using ORLTs in accordance with plate buckling theory and previously developed formulas for predicting the shear strength of SBCWs. The proposed ORLT models are implemented using the regression learner toolbox of MATLAB software (2020b). The available data of more than 125 test results from different specimens prepared by previous researchers are used to create the model. In this study, web geometry and relevant web steel grades determine the shear capacity of SBCWs. Four regression methods are adopted. Results are compared with those of an artificial neural network model. The model output factor represents the ratio of the web vertical shear stress to the normalised shear stress. Shear capacity can be estimated on the basis of the resulting factor from the model. The proposed model is verified using two methods. In the first method, a series of tests are performed by the authors. In the second method, the results of the model are compared with the shear values obtained experimentally by other researchers. On the basis of the test results of previous studies and the current work, the proposed model provides an acceptable degree of accuracy for predicting the shear capacity of SBCWs. The results obtained using Gaussian process regression are the most appropriate because its recoded mean square error is 0.07%. The proposed model can predict the shear capacity of SBCWs with an acceptable percentage of error. The recoded percentage of error is less than 5% for 93% of the total specimens. By contrast, the maximum differential obtained is ±10%, which is recorded for 3 out of 125 specimens.

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