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Number of results: 7
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Abstract

The rapid development of grid integration of solar energy in developing countries like India has created vital concerns such as fluctuations and interruptions affecting grid operations. Improving the consistency and accuracy of solar energy forecasts can increase the reliability of the power grid. Although solar energy is available in abundance around the world, it is viewed as an unpredictable source due to uncertain fluctuations in climate conditions. Global horizontal irradiance (GHI) prediction is critical to efficiently manage and forecast the power output of solar power plants. However, developing an accurate GHI forecasting model is challenging due to the variability of weather conditions over time. This research aims to develop and compare univariate LSTM models capable of predicting GHI in a solar power plant in India over the short term. The present study introduces a deep neural network-based (DNN) hybrid model with a combination of convolutional neural network bi-directional long short-term memory (CNN BiLSTM) to predict the one minute interval GHI of a solar power plant located in the southern region of India. The model’s effectiveness was tested using data for the month of January 2023. In addition, the results of the hybrid model were compared to the long short-term memory (LSTM) and BiLSTM deep-learning (DL) models. It has been observed that the proposed hybrid model framework is more accurate compared to the LSTM and BiLSTM architectures. Finally, a GHI prediction tool was developed to understand the trend of the results.
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Authors and Affiliations

S.V.S. Rajaprasad
1
ORCID: ORCID
Rambabu Mukkamala
1
ORCID: ORCID

  1. National Institute of Construction Management and Research (NICMAR), Hyderabad,Telangana, India
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Abstract

This paper describes modifications of the Mayr and Cassie models of the electric arc. They include the phenomena of increased heat dissipation and non-zero residual conductance when the current passes through zero. The modified models are combined into a new hybrid model connecting them in parallel and activated by a weight function. Two cases of functional dependence of models on current intensity and instantaneous conductance are considered. Mathematical models in differential and integral forms are presented. On their basis, computer macromodels are created and simulations of processes in circuits with arc models are performed. The families of static and dynamic arc voltage and current characteristics are presented.
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Bibliography

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[2] Sawicki A., Haltof M., Spectral and integral methods of determining parameters in selected electric arc models with a forced sinusoid current circuit, Archives of Electrical Engineering, vol. 65, no. 1, pp. 87–103 (2016), DOI: 10.1515/aee-2016-0007.
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[5] Sawicki A., The universal Mayr–Pentegov model of the electric arc, Przegl˛ad Elektrotechniczny (Electrical Review), vol. 94, no. 12, pp. 208–211 (2019), DOI: 10.15199/48.2019.12.47.
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[7] Maximov S., Venegas V., Guardado J.L., Melgoza E., Torres D., Asymptotic methods for calculating electric arc model parameters, Electrical Engineering, vol. 94, no. 2, pp. 89–96 (2012), DOI: 10.1007/s00202-011-0214-6.
[8] Sawicki A., Arc models for simulating processes in circuits with a SF6 circuit breaker, Archives of Electrical Engineering, vol. 68, no. 1, pp. 147–159 (2019), DOI: 10.24425/aee.2019.125986.
[9] Sawicki A., Classical and Modified Mathematical Models of Electric Arc, Institute ofWelding Bulletin, no. 4, pp. 67–73 (2019), DOI: 10.17729/ebis.2019.4/7.
[10] Janowski T., Jaroszynski L., Stryczewska H.D., Modification of the Mayr’s electric arc model for gliding Arc Analysis, XXVI International Conference on Phenomena in Ionized Gases, Nagoya, Japan 2001/7/17, pp. 341–342 (2001).
[11] Ziani A., Moulai H., Hybrid model of electric arcs in high voltage circuit breakers, Electric Power Systems Research, vol. 92, pp. 37–42 (2012), DOI: 10.1016/j.epsr.2012.04.021.
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Authors and Affiliations

Antoni Sawicki
1
ORCID: ORCID

  1. Association of Polish Electrical Engineers (NOT-SEP), Czestochowa Division, Poland
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Abstract

The homogenous properties – as flats are – have the set of key features that characterizes them. The area of a flat, the number of rooms and storey number where it is located, the technical state of a building, and the state of the vicinity of the blocks of flats assessed. The database comprises 222 flats with their transaction prices on the secondary estate market. The analysed flats are located in a certain quarter of Wrocław city in Poland. The database is large enough to apply machine learning for successful price predictions. Their close locations significantly lower the influence of clients’ assessments of the attractiveness of the location on the flat’s price. The hybrid approach is applied, where classifying precedes the solution of the regression problem. Dependently on the class of flats, the mean absolute percentage error achieved through the calculations presented in the article varies from 4,4 % to 7,8 %. In the classes of flats where the number of cases doesn’t allow for machine predicting, multivariate linear regression is applied. The reliable use of machine learning tools has proved that the automated valuation of homogenous types of properties can produce price predictions with the error low enough for real applications.
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Authors and Affiliations

Hubert Anysz
1
ORCID: ORCID
Monika Podwórna
2
Nabi Ibadov
1
ORCID: ORCID
Kunibert Lennerts
3
Kostiantyn Dikarev
4

  1. Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16, 00-637 Warsaw, Poland
  2. Wrocław University of Science and Technology, Faculty of Civil Engineering , Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland
  3. Karlsruhe Institute of Technology, Institute of Technology and Management in Construction, Gotthard-Franz-Street 3, 76131 Karlsruhe, Germany
  4. Prydniprovska State Academy of Civil Engineering and Architecture, Department of Construction Technology, 24a, Chernyshevskogo St., Dnipro, 49005, Ukraine
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Abstract

This study describes the methodology for modelling a worm and worm wheel of a double enveloping worm gear with the use of a CAD system. An algorithm for generating a globoid helix is described. In addition, the methodology for modelling an hourglass worm thread with a straight axial tooth profile is presented. The shape of the hourglass worm tooth end with and without a trace modification is proposed. Moreover, a method for achieving a geometric modification of the tooth trace was developed. Next, the method for modelling the worm wheel teeth is described. A solid model of using a machining worm as a hob is applied. Owing to the limitations of a CAD system, which prevents the use of a direct machining simulation, an indirect modelling method is introduced. In the present study, different CAD techniques, both solid and surface, are applied. Knowledge of the correct modelling of the hourglass worm and worm wheel facilitates their generation and conducting various analyses, including a tooth contact analysis. CAD models are utilised to analyse the geometrical contact pattern in a CAD environment, to carry out FEM analysis, to manufacture real parts or to prototype models using the technique of rapid prototyping. They can be also used as master models for measurement, e.g. in optical technics.
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Authors and Affiliations

Piotr Połowniak
1
ORCID: ORCID
Mariusz Sobolak
1
ORCID: ORCID
Adam Marciniec
1
ORCID: ORCID

  1. Rzeszow University of Technology, The Faculty of Mechanical Engineering and Aeronautics, al. Powstańców Warszawy 12, 35-959 Rzeszow, Poland
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Abstract

The study examines various approaches oriented towards conceptual and numerical reduction of first-principle models, data-driven methodologies for surrogate (black box) and hybrid (grey box) modeling, and addresses the prospect of using digital twins in chemical and process engineering. In the case of numerical reduction of mechanistic models, special attention is paid to methodologies in which simulation data are used to construct light but robust numerical models while preserving all the physics of the problem, yielding reduced-order datadriven but still white-box models. In addition to reviewing various methodologies and identifying their applications in chemical engineering, including industrial process engineering, as well as fundamental research, the study outlines associated problems and challenges, as well as the risks posed by the era of big data.
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Authors and Affiliations

Katarzyna Bizon
1
ORCID: ORCID

  1. Cracow University of Technology, Faculty of Chemical Engineering and Technology,Warszawska 24, 31-155 Kraków, Poland
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Abstract

Artificial neural networks are widely employed as data mining methods by researchers across various fields, including rainfall-runoff (R-R) statistical modelling. To enhance the performance of these networks, deep learning (DL) neural networks have been developed to improve modelling accuracy. The present study aims to improve the effectiveness of DL networks in enhancing the performance of artificial neural networks via merging with the gradient boosting (GB) technique for daily runoff data forecasting in the river Amu Darya, Uzbekistan. The obtained results showed that the new hybrid proposed model performed exceptionally well, achieving a 16.67% improvement in determination coefficient ( R2) and a 23.18% reduction in root mean square error ( RMSE) during the training phase compared to the single DL model. Moreover, during the verification phase, the hybrid model displayed remarkable performance, demonstrating a 66.67% increase in R 2 and a 50% reduction in RMSE. Furthermore, the hybrid model outperformed the single GB model by a significant margin. During the training phase, the new model showed an 18.18% increase in R 2 and a 25% reduction in RMSE. In the verification phase, it improved by an impressive 75% in R 2 and a 33.33% reduction in RMSE compared to the single GB model. These findings highlight the potential of the hybrid DL-GB model in improving daily runoff data forecasting in the challenging hydrological context of the Amu Darya River basin in Uzbekistan.
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Authors and Affiliations

Barno S. Abdullaeva
1
ORCID: ORCID

  1. Tashkent State Pedagogical University, Faculty of Math and Physics, 27 Bunyodkor Ave, 100070, Tashkent, Uzbekistan

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