Effectiveness of un-decimated wavelet transform in time-series forecasting: A PV power calculation case study in BTU
| dc.authorid | 0000-0003-0423-1968 | |
| dc.authorid | 0000-0002-5136-0829 | |
| dc.authorid | 0000-0001-9613-6620 | |
| dc.contributor.author | Albayram, Mehmet | |
| dc.contributor.author | Yilmaz, Alper | |
| dc.contributor.author | Bayrak, Gokay | |
| dc.contributor.author | Basaran, Kivanc | |
| dc.contributor.author | Popescu, Luminita Georgeta | |
| dc.date.accessioned | 2026-02-08T15:15:28Z | |
| dc.date.available | 2026-02-08T15:15:28Z | |
| dc.date.issued | 2026 | |
| dc.department | Bursa Teknik Üniversitesi | |
| dc.description.abstract | This study explored the effectiveness of Un-Decimated Wavelet Transform (UWT) in time-series applications, using photovoltaic (PV) calculation as a case study. Real-time measurements of irradiance, ambient temperature, module temperature, and humidity were collected at 5-min intervals from a 1.2 kW rooftop PV system at Bursa Technical University. Wavelet-based features extracted with both UWT and the conventional Discrete Wavelet Transform (DWT) were combined with regression and tree-based learners to build 16 hybrid models. The results show that the shift-invariant UWT significantly improves both feature extraction and prediction accuracy compared to the DWT approach. The UWT-DT model achieved the highest accuracy, with the lowest MSE (0.0001), the lowest RMSE (0.0118) and the highest R-2 coefficient (0.9986). A Wilcoxon signed-rank test applied to paired RMSE values confirmed that these improvements were statistically significant (p value < 0.05 for UWTDT vs DWT-DT). In terms of computational complexity, the 'a` trous' algorithm used in UWT requires convolution operations at every level, resulting in higher processing costs than DWT (12 ms feature extraction per 1024-sample input). However, the full-resolution features provided by UWT significantly reduced the error rates of treebased models, raising R-2 above 0.99. | |
| dc.description.sponsorship | Ministry of Research, Innovation and Digitalization [PNRR-C9-I8-760089/23.05.2023, CF31/14.11.2022] | |
| dc.description.sponsorship | This work was supported by a grant of the Ministry of Research, Innovation and Digitalization, project number PNRR-C9-I8-760089/23.05.2023, code CF31/14.11.2022. | |
| dc.identifier.doi | 10.1016/j.renene.2025.124062 | |
| dc.identifier.issn | 0960-1481 | |
| dc.identifier.issn | 1879-0682 | |
| dc.identifier.scopus | 2-s2.0-105011590709 | |
| dc.identifier.scopusquality | Q1 | |
| dc.identifier.uri | https://doi.org/10.1016/j.renene.2025.124062 | |
| dc.identifier.uri | https://hdl.handle.net/20.500.12885/5778 | |
| dc.identifier.volume | 256 | |
| dc.identifier.wos | WOS:001543573200001 | |
| dc.identifier.wosquality | Q1 | |
| dc.indekslendigikaynak | Web of Science | |
| dc.indekslendigikaynak | Scopus | |
| dc.language.iso | en | |
| dc.publisher | Pergamon-Elsevier Science Ltd | |
| dc.relation.ispartof | Renewable Energy | |
| dc.relation.publicationcategory | Makale - Uluslararası Hakemli Dergi - Kurum Öğretim Elemanı | |
| dc.rights | info:eu-repo/semantics/closedAccess | |
| dc.snmz | WOS_KA_20260207 | |
| dc.subject | Un-decimated wavelet transform | |
| dc.subject | Machine learning | |
| dc.subject | Regression | |
| dc.subject | Ensemble learning | |
| dc.subject | PV power forecasting | |
| dc.title | Effectiveness of un-decimated wavelet transform in time-series forecasting: A PV power calculation case study in BTU | |
| dc.type | Article |












