Quantifying ENSO impacts at the basin scale using the Iterative Input variable Selection algorithm

Medium-to-long range streamflow predictions provide a key assistance in anticipating hydro- climatic adverse events and prompting effective adaptation measures. In this context, recent modelling efforts have been dedicated to seasonal and inter-annual predictions based on the teleconnection between at-site hydrological processes and large-scale, low-frequency climate fluctuations, such as El Nino Southern Oscillation (ENSO). This work proposes a novel procedure for first detecting the impact of ENSO on hydro-meteorological processes at the basin scale, and then quantitatively assessing the potential of ENSO indexes for building medium-to-long range streamflow prediction models. Core of this procedure is the adoption of the Iterative Input variable Selection (IIS) algorithm, which is employed to find the most relevant determinants of streamflow variability and derive predictive models based on the selected inputs. The procedure is tested on two different case studies, the Columbia River (US) and the Williams River (Australia), whose sensitivity to ENSO fluctuations has been documented in previous studies. Results show that IIS outcomes for both case studies are consistent with the results of previous analyses conducted with state-of-the-art detection methods, and that ENSO indexes can effectively be used in both regions to enhance the accuracy of streamflow prediction models

An evaluation framework for input variable selection algorithms for environmental data-driven models

Abstract not availableStefano Galelli, Greer B. Humphrey, Holger R. Maier, Andrea Castelletti, Graeme C. Dandy, Matthew S. Gibb

Water Resources Management - Singapore University of Technology and Design

Undergraduate course in Water Resources Management offered at Singapore University of Technology and Design in Spring 2015

INVESTIGATING THE ORIGINS OF UHECRS USING THE PIERRE AUGER OBSERVATORY AND PALEO-DETECTORS

A very fascinating region for investigating the origins of cosmic rays is the toe of the ultra-high energy cosmic ray (UHECR) spectrum, above ≈ 50 EeV. The potential for small magnetic deflections at these energies is coupled with the presence of flux suppression, which may be a sign of the sources’ maximum acceleration potential or may have an explanation for the interactions of cosmic rays with background photons, effectively restricting the region of interest in the search for UHECR sources to a relatively small bubble around us. In this thesis, I present the latest dataset of cosmic rays at the highest energies collected by the Pierre Auger Observatory, the largest experiment dedicated to UHECR science ever built, and the anisotropy searches carried out using it. I have carried out blind, model-independent searches for overdensities, astrophysical structural correlation analysis, and cross-correlation investigations with catalogs of candidate sources. For UHECRs with energy greater than 38 EeV, the results show evidence of a deviation from isotropy at an angular scale of ≈ 25◦ at the 4σ level. Additionally in this thesis for the first time, I present the possibility of using ancient minerals as paleo-detectors to study the history of the flux of cosmic rays in the past by detecting the tracks left in the mineral structure by the interactions between ions and energetic secondary cosmic rays present in the extensive airshowers

Assessing the predictive capability of randomized tree-based ensembles in streamflow modelling

Abstract. Combining randomization methods with ensemble prediction is emerging as an effective option to balance accuracy and computational efficiency in data-driven modelling. In this paper, we investigate the prediction capability of extremely randomized trees (Extra-Trees), in terms of accuracy, explanation ability and computational efficiency, in a streamflow modelling exercise. Extra-Trees are a totally randomized tree-based ensemble method that (i) alleviates the poor generalisation property and tendency to overfitting of traditional standalone decision trees (e.g. CART); (ii) is computationally efficient; and, (iii) allows to infer the relative importance of the input variables, which might help in the ex-post physical interpretation of the model. The Extra-Trees potential is analysed on two real-world case studies – Marina catchment (Singapore) and Canning River (Western Australia) – representing two different morphoclimatic contexts. The evaluation is performed against other tree-based methods (CART and M5) and parametric data-driven approaches (ANNs and multiple linear regression). Results show that Extra-Trees perform comparatively well to the best of the benchmarks (i.e. M5) in both the watersheds, while outperforming the other approaches in terms of computational requirement when adopted on large datasets. In addition, the ranking of the input variable provided can be given a physically meaningful interpretation

Il pedagogista in quanto diversity manager e mediatore tra Università e Mondo del Lavoro

The diversity of gender, culture, ability is recognized as a value both at the level of common sense and in the context of national and European legislation. It is necessary to question the effectiveness of work placement strategies, as a human qualification device, of disabled people who complete their university studies. How to manage risks and opportunities in order to effectively guide the work placement of disabled people who reach the end of their university career? This contribution aims to offer an in-depth study on the subject, with a particular focus on the figure of the pedagogist as a pedagogical operator of mediation between the University and the world of work.La diversità di genere, cultura, abilità è riconosciuta in quanto valore sia a livello del senso comune sia nel contesto nella Legislazione europea. È necessario, pertanto, interrogarsi circa l’efficacia delle strategie di collocamento lavorativo in quanto dispositivo di qualificazione umana e professionale, delle persone con disabilità che abbiano completato il proprio percorso di studi universitari. Come gestire rischi e opportunità al fine di guidare di il percorso di collocamento lavorativo per soggetti con disabilità che abbiano concluso il proprio percorso universitario? Il presente contributo si propone di offrire uno studio dell’argomento, con una particolare attenzione alla figura del  pedagogista in quanto mediatore tra Università e mondo del Lavoro