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Evaluation of the performance of data-driven approaches for filling monthly precipitation gaps in a semi-arid climate conditions

Katipoğlu Okan Mert

Acta Geophysica

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2023

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Vol. 71, no. 5

2265--2285

EN

Missing data cause problems in meteorological, hydrological, and climate analysis. The observation data should be complete and cover long periods to make the research more accurate and reliable. Artificial intelligence techniques have attracted interest for completing incomplete meteorological data in recent years. In this study the abilities of machine learning models, artificial neural networks, the nonlinear autoregressive with exogenous input (NARX) model, support vector regression, Gaussian processes regression, boosted tree, bagged tree (BAT), and linear regression to fill in missing precipitation data were investigated. In developing the machine learning model, 70% of the dataset was used for training, 15% for testing, and 15% for validation. The Bayburt, Tercan, and Zara precipitation stations, which are closest to the Erzincan station and have the highest correlation coefficients, were used to fill the data gaps. The accuracy of the constructed models was tested using various statistical criteria, such as root-mean-square error (RMSE), mean absolute error (MAE), Nash–Sutcliffe model efficiency coefficient (NSE), and determination coefficient (R2) and graphical approaches such as scattering, box plots, violin plots, and Taylor diagrams. Based on the comparison of model results, it was concluded that the BAT model with R2: 0.79 and NSE: 0.79 and error (RMSE: 11.42, and MAE: 7.93) was the most successful in the completion of missing monthly precipitation data. The contribution of this research is assist in the choice of the best and most accurate method for estimating precipitation data in semi-arid regions like Erzincan.

2

A relaying scheme for detection and classification of shunt faults in six-phase transmission system based on DFT-FIS approach

Ashok V., Yadav A.

Journal of Power Technologies

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2018

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Vol. 98, nr 2

202--211

EN

Hitherto many schemes based on the fuzzy system have been protected by a three-phase transmission system, but not by a six-phase transmission system. This paper sets out a novel protection scheme based on DFT-FIS approach for detection/classification of shunt faults in a six-phase transmission system. In this scheme, two separate DFT-FIS modules have been designed to detect the presence of fault in any of the six-phase(s) and to identify the presence of ground in the fault loop, thus classifying all 120 types of fault in a six-phase transmission line. The six-phase voltage and current signals are collected at one end of the transmission line only, thus circumvent dependence on a communication link for remote end data. A widerange of fault simulation studies were carried out in MATLAB/Simulink environment for all possible shunt fault combinations by varying fault locations, fault inception angle, fault resistance, short circuit capacity (SCC) of the source and at various fault conditions such as: close-in faults, remote-end faults, high resistance faults, including CT saturation. Furthermore, the relay operation time in fault detection/classification is less than one-cycle (<16.67ms) and since the scheme does not experience any malfunction it is deemed reliable and adaptable.

3

Wieżowce Warszawy 2012

Pawłowski A. Z.

Budownictwo, Technologie, Architektura

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2012

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nr 1

46-49

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Możliwości zastosowania szybkiego prototypowania w procesie projektowania i wytwarzania elementów pojazdów samochodowych

Budzik G., Budzik W., Cygnar M., Janisz K.

Problemy Eksploatacji

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2009

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nr 1

7-16

PL

Artykuł przedstawia możliwości zastosowania szybkiego prototypowania w procesie projektowania i wytwarzania pojazdów samochodowych. Prototypy przedstawione w artykule zostały wykonane metodą trójwymiarowego druku (Three Dimensional Printing - 3DP). W pierwszej części artykułu zostały opisane zasady wytwarzania prototypów z wykorzystaniem przyrostowych metod szybkiego prototypowania (Rapid Prototyping - RP). Przedstawione zostały również możliwości metod RP oraz ich miejsce w procesie technologicznym wytwarzania elementów pojazdów samochodowych - elementów silnika, elementów układu napędowego i nadwozia. Opisany został proces przygotowania budowy prototypów techniką 3DP, począwszy od etapu projektowania poprzez obróbkę programową danych, skończywszy na budowie prototypu fizycznego. Przedstawiona została również możliwość wykorzystania metody 3DP jako techniki szybkiego wytwarzania narzędzi (Rapid Tooling - RT). Przedstawiona w artykule analiza możliwości wykorzystania systemów RP w przemyśle samochodowym oraz dynamiczny rozwój tych systemów pokazuje, że obszar zastosowań szybkiego prototypowania w dziedzinie motoryzacji stale się powiększa. Techniki RP pozwalają również na skrócenie procesu projektowania i wytwarzania elementów pojazdów samochodowych.

EN

The article presents the possibilities of application of rapid prototyping (RP) in process of designing and manufacturing of car vehicles. The presented prototypes in article were created by method of three-dimensional printing (Three Dimensional Printing - 3DP).The principles of manufacturing of prototypes with application of additive methods of rapid prototyping (Rapid Prototyping - RP) were described in the first part of article. Possibilities of methods RP and also their place in technological process of manufacturing of elements of car vehicles i.e. elements of engine, elements of the driving system and car body also were presented. Process of preparation of building of prototypes by means of technique 3DP was described to begin with stage of designing and across the program processing of data and to finish on building of physical prototype. Possibility of application of method 3DP as technique of rapid manufacturing of tools (Rapid Tooling - RT) also was presented. Presented in article analysis of possibilities of application systems RP in car industry and dynamic development of these systems shows, that the area of applications of rapid prototyping in the range of the motorization still increases. Techniques RP also enable on shortening of process of designing and manufacturing of elements of car vehicles.