Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2019
Sammendrag
Surface mould growth contributes to the colour changes of outdoor exposed wood over time. Modelling mould growth can thus help visualize wooden facades’ colour development, which can improve facade design and service life. However, existing wood mould models do not consider transient wetting effects that occur outdoors due to precipitation and condensation. To address this, four mould models were evaluated using laboratory experimental data that included exposure to transient wetting. First, the models (the original and the updated VTT model, the biohygrothermal model and the mould resistance design (MRD) model) were evaluated for Scots pine sapwood. For this evaluation, the transient wetting effect was implemented in the models by using hourly wood surface relative humidity (RH), calculated from electrical resistance measurements, as input. This showed that the original and the updated VTT model gave best fit to the experimental data. However, further evaluation of these two models for more wood materials showed that the updated VTT model was sensitive to the choice of material parameters. Large discrepancies occurred when varying the material parameters in the updated VTT model. Finally, different estimates of RH were tested in the original VTT model. Using wood surface RH as input gave best fit to the experimental data, and ambient air RH gave poorest fit. Overall, the results indicate that the original VTT model is fairly reliable and can be used to predict mould growth on wooden claddings exposed to transient wetting as long as the wood surface climate is used as climatic input data.
Forfattere
Tao Zhao Suresh Ganji Christian Schiebe Björn Bohman Philip Weinstein Paal Krokene Anna-Karin Borg-Karlson C. Rikard UneliusSammendrag
Det er ikke registrert sammendrag
Forfattere
Fernanda Canassa Susanna Tall Rafael de Andrade Moral Idemauro A.R. de Lara Italo Delalibera Jr. Nicolai Vitt MeylingSammendrag
Det er ikke registrert sammendrag
Forfattere
Jamal Zaherpour Nick Mount Simon N. Gosling Rutger Dankers Stephanie Eisner Dieter Gerten Xingcai Liu Yoshimitsu Masaki Hannes Müller Schmied Qiuhong Tang Yoshihide WadaSammendrag
This study presents a novel application of machine learning to deliver optimised, multi-model combinations (MMCs) of Global Hydrological Model (GHM) simulations. We exemplify the approach using runoff simulations from five GHMs across 40 large global catchments. The benchmarked, median performance gain of the MMC solutions is 45% compared to the best performing GHM and exceeds 100% when compared to the ensemble mean (EM). The performance gain offered by MMC suggests that future multi-model applications consider reporting MMCs, alongside the EM and intermodal range, to provide end-users of GHM ensembles with a better contextualised estimate of runoff. Importantly, the study highlights the difficulty of interpreting complex, non-linear MMC solutions in physical terms. This indicates that a pragmatic approach to future MMC studies based on machine learning methods is required, in which the allowable solution complexity is carefully constrained.
Forfattere
Valentina Picchi Roberto Lo Scalzo Elisabeth Kurze Marta Fibiani Eivind Vangdal Wilfried SchwabSammendrag
The present work studied the effect of the year of harvest, the genotype and the cultivation method on the nutritional quality and the allergen content of three plum cultivars. The common quality parameters and the phytochemical content strongly varied with the year and the cultivar, while the system of cultivation had a minor influence. In particular, ascorbic acid greatly decreased in 2016 compared to 2015, while polyphenols were higher in 2016. The health-promoting compounds, and particularly phenolics, were significantly correlated with the antioxidant capacity. Finally, the allergen content was strongly dependent on the content of flavan-3-ols, suggesting that this class of phenolics is determinant in influencing the allergen content in plums. Results showed that the major factor affecting the quality and the concentration of natural metabolites of plum, in addition to the diversity among genotypes, is the year-to-year variation, whereas the system of cultivation plays a marginal role.
Forfattere
Paal KrokeneSammendrag
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Forfattere
Paal KrokeneSammendrag
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Sammendrag
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Forfattere
Masoud Mahdianpari Mahdi Motagh Vahid Akbari Fariba Mohammadimanesh Bahram SalehiSammendrag
Synthetic Aperture Radar (SAR) data have gained interest for a variety of remote sensing applications, given the capability of SAR sensors to operate independent of solar radiation and day/night conditions. However, the radiometric quality of SAR images is hindered by speckle noise, which affects further image processing and interpretation. As such, speckle reduction is a crucial pre-processing step in many remote sensing studies based on SAR imagery. This study proposes a new adaptive de-speckling method based on a Gaussian Markov Random Field (GMRF) model. The proposed method integrates both pixel-wised and contextual information using a weighted summation technique. As a by-product of the proposed method, a de-speckled pseudo-span image, which is obtained from the least-squares analysis of the de-speckled multi-polarization channels, is also produced. Experimental results from the medium resolution, fully polarimetric L-band ALOS PALSAR data demonstrate the effectiveness of the proposed algorithm compared to other well-known de-speckling approaches. The de-speckled images produced by the proposed method maintainthe mean value of the original image in homogenous areas, while preserving the edges of features in heterogeneous regions. In particular, the equivalent number of look (ENL) achieved using the proposed method improves by about 15% and 47% compared to the NL-SAR and SARBM3D de-speckling approaches, respectively. Other evaluation indices, such as the mean and variance of the ratio image also reveal the superiority of the proposed method relative to other de-speckling approaches examined in this study.
Forfattere
Tomáš Hlásny Paal Krokene Andrew Liebhold Claire Montagné-Huck Jörg Müller Hua Qin Kenneth F Raffa Mart-Jan Schelhaas Rupert Seidl Miroslav Svoboda Heli ViiriSammendrag
Det er ikke registrert sammendrag