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您的检索式：作者名="Petru Andrei"
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| 1 | Classification of Soil Types Using Geographic Object-Based Image Analysis and Random Forests显示文摘There is increasing interest in developing automatic procedures to segment landscapes into soil spatial entities that replace conventional, expensive manual procedures for delineating and classifying soils. Geographic object-based image analysis(GEOBIA)partitions remote sensing imagery or digital elevation models into homogeneous image objects based on image segmentation. We used an object-based methodology for the detailed delineation and classification of soil types using digital maps of topography and vegetation as soil covariates, based on the Random Forests(RF) classifier. We compared the object-based method's results with those of a pixel-based classification using the same classifier. We used 18 digital elevation model derivatives and 5 remote sensing indices that were related to vegetation cover and soil. Using 171 soil profiles with their associated environmental variable values,the RF method was used to identify the most important soil type predictors for use in the segmentation process. A stack of rastergeodatasets corresponding to the selected predictors was segmented using a multi-resolution segmentation algorithm, which resulted in homogeneous objects related to soil types. These objects were further classified as soil types using the same method, RF. We also conducted a pixel-based classification using the same classifier and soil profiles, and the resulting maps were assessed in terms of their accuracy using 30% of the soil profiles for validation. We found that GEOBIA was an effective method for soil type mapping, and was superior to the pixel-based approach. The optimized object-based soil map had an overall accuracy of 58%, which was 10% higher than that of the optimized pixel-based map. | Andrei DORNIK Lucian DRAGUT Petru URDEA | 2018 | Pedosphere2018，28，6： | 4 |
| 2 | High-energy hybrid femtosecond laser system demonstrating 2×10 PW capability显示文摘We report on a two-arm hybrid high-power laser system(HPLS)able to deliver 2×10 PW femtosecond pulses,developed at the Bucharest-Magurele Extreme Light Infrastructure Nuclear Physics(ELI-NP)Facility.A hybrid frontend(FE)based on a Ti:sapphire chirped pulse amplifier and a picosecond optical parametric chirped pulse amplifier based on beta barium borate(BBO)crystals,with a cross-polarized wave(XPW)filter in between,has been developed.It delivers 10 mJ laser pulses,at 10 Hz repetition rate,with more than 70 nm spectral bandwidth and high-intensity contrast,in the range of 1013:1.The high-energy Ti:sapphire amplifier stages of both arms were seeded from this common FE.The final high-energy amplifier,equipped with a 200 mm diameter Ti:sapphire crystal,has been pumped by six 100 J nanosecond frequency doubled Nd:glass lasers,at 1 pulse/min repetition rate.More than 300 J output pulse energy has been obtained by pumping with only 80%of the whole 600 J available pump energy.The compressor has a transmission efficiency of 74%and an output pulse duration of 22.7 fs was measured,thus demonstrating that the dual-arm HPLS has the capacity to generate 10 PW peak power femtosecond pulses.The reported results represent the cornerstone of the ELI-NP 2×10 PW femtosecond laser facility,devoted to fundamental and applied nuclear physics research. | François Lureau Guillaume Matras Olivier Chalus Christophe Derycke Thomas Morbieu Christophe Radier Olivier Casagrande Sébastien Laux Sandrine Ricaud Gilles Rey Alain Pellegrina Caroline Richard Laurent Boudjemaa Christophe Simon-Boisson Andrei Baleanu Romeo Banici Andrei Gradinariu Constantin Caldararu Bertrand De Boisdeffre Petru Ghenuche Andrei Naziru Georgios Kolliopoulos Liviu Neagu Razvan Dabu Ioan Dancus Daniel Ursescu | 2020 | High Power Laser Science and Engineering2020，8，4： | 4 |
| 3 | 显示文摘 | Petru Andrei | 1999 | J Magn Magn Mater1999，362，： | 1 |
| 4 | Rate Dependence of First-order Reversal Curves By Using a Dynamic Preisach Model of Hysteresis显示文摘 | Petru Andrei Ovidiu Caltun Alexandru Stancu | 2006 | Physica B2006，372，： | 1 |
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