Tuscia University

Unitus DSpace
Not a member yet
    2551 research outputs found

    Projecting Nonnative Douglas Fir Plantations in Southern Europe with the Forest Vegetation Simulator

    Get PDF
    In Italy, Douglas-fir has great potential in terms of wood production and drought tolerance. However, a growth reference for mature stands is lacking. We calibrated and validated the Pacific Northwest variant of the Forest Vegetation Simulator (FVS) for Douglas-fir plantations in Italy and then ran the calibrated model to test management alternatives. We calibrated the height-diameter, crown width, crown ratio, and diameter increment submodels of the FVS using multipliers fitted against tree measurements (n 704) and increment cores (n 180) from 20 plots. Validation was carried out on tree-level variables sampled in 1996 and 2015 in two independent permanent plots (275 trees). Multiplier calibration improved the error of crown submodels by 7–19%; self-calibration of the diameter growth submodel produced scale factors of 1.0 –5.2 for each site. Validation of 20-year simulations was more satisfactory for tree diameter ( 6% to 1% mean percent error) than for height ( 10% to 8%). Calibration reduced the error, relative to that of yield tables, of the predicted basal area and yield after 50 years. Simulated responses to thinning diverged, depending on site index and competition intensity. The FVS is a viable option for modeling the yield of Douglas-fir plantations in Italy, reflecting the current understanding of forest ecosystem dynamics and how they respond to management interventions

    AutoRE (Automotive Derivative Energy System). 2 Years in

    Get PDF
    AutoRE is a multi- partner project funded under the FCH-JU FCH-02.5-2014 call, aimed at demonstrating an automotive derivative fuel cell integrated with a natural gas reformer to make the required high purity hydrogen. The system prototype, to be demonstrated at GE’s Rugby site in the UK, has a targeted electrical efficiency of 38-40%, with parallel component developments, such as hydrogen separation membranes, undertaken to increase the efficiency of a subsequent commercial system to >45%. The market for the product will be 50-100kWe applications in industrial and commercial buildings in combined heat and power (CHP) mode. At this scale, the fuel cell based CHP system has potential cost of electricity and emissions advantage over competing technologies. The project is now in its third year, with the build of the prototype system significantly underway. This paper gives the status of the project as reported at the mid-term meeting.This project has received funding from the Fuel Cells and Hydrogen Joint Undertaking under grant agreement No 671396. This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme and UK, Germany, Greece, Croatia, Italy, Switzerland, Norway. Swiss partners are funded by the State Secretariat for Education, Research & Innovation of the Swiss Confederation

    Predicting carbon dioxide and energy fluxes across global FLUXNET sites with regression algorithms

    Get PDF
    Spatio-temporal fields of land–atmosphere fluxes derived from data-driven models can complement simulations by process-based land surface models. While a number of strategies for empirical models with eddy-covariance flux data have been applied, a systematic intercomparison of these methods has been missing so far. In this study, we performed a cross-validation experiment for predicting carbon dioxide, latent heat, sensible heat and net radiation fluxes across different ecosystem types with 11 machine learning (ML) methods from four different classes (kernel methods, neural networks, tree methods, and regression splines). We applied two complementary setups: (1) 8-day average fluxes based on remotely sensed data and (2) daily mean fluxes based on meteorological data and a mean seasonal cycle of remotely sensed variables. The patterns of predictions from different ML and experimental setups were highly consistent. There were systematic differences in performance among the fluxes, with the following ascending order: net ecosystem exchange (R2 < 0.5), ecosystem respiration (R2 > 0.6), gross primary production (R2> 0.7), latent heat (R2 > 0.7), sensible heat (R2 > 0.7), and net radiation (R2 > 0.8). The ML methods predicted the across-site variability and the mean seasonal cycle of the observed fluxes very well (R2 > 0.7), while the 8-day deviations from the mean seasonal cycle were not well predicted (R2 < 0.5). Fluxes were better predicted at forested and temperate climate sites than at sites in extreme climates or less represented by training data (e.g., the tropics). The evaluated large ensemble of ML-based models will be the basis of new global flux products

    Viaggiatori inglesi in Italia nel Cinque e Seicento

    Get PDF
    Il volume contiene notizie relative ai viaggiatori inglesi che hanno visitato a vario titolo l'Italia e altri paesi europei, dell'area mediterranea e del Vicino Oriente tra Cinque e Seicento, lasciando relazioni e diari di viaggio. Il testo è corredato da un’ampia bibliografia che comprende, oltre alle varie edizioni delle opere degli autori presi in esame, tutte le pubblicazioni più utili sul tema del Grand Tour e dei viaggi in Italia e in Europa in generale, con particolare riferimento al Cinquecento e al Seicento

    I prestiti greci nel Paterik Alfabetico antico-slavo

    Get PDF
    In questo contributo l'autore cerca di delineare un quadro dei prestiti greci nel Paterík Alfabetico antico slavo ecclesiastico, una raccolta di vite e detti dei padri del deserto tradotta appunto dal greco. La percentuale di grecismi è inferiore rispetto ad opere consimili come il Sinajskij Paterík o il Rimskij Paterík. In ogni caso non sembra possibile parlare di una revisione sistematica volta ad eliminare per quanto possibile i grecismi, secondo i moduli della Scuola di Preslav. L'autore prende poi in considerazione i diversi ambiti semantici del lessico, alcuni dei quali presentano rispetto al problema in esame delle interessanti specificità.In this paper the author tries to sketch a picture of the Greek loan-words in OCS Alphabetic Paterík. Their rate is inferior in comparison with other hagiographical works like Sinajskij Paterík or Rimskij Paterík. Anyway, one could not assert that AP was subjected to a thorough lexical revision in the way of Preslav School, aiming to a systematic elimination of Greek loan-words

    L'antifascismo tra Italia ed Europa

    Get PDF
    The essay sketches a comparison between Italian anti-fascism and international anti-fascism as political categorie

    Linguaggi e tecnologia: usi della lingua e strumenti di rete

    Get PDF
    The paper deals with the use of italian language within the digital media environment. Special attention is devoted to the written language of e-mails, blogs, SMS, Twitter, social networks.Pre-print of a paper published in "Il libro dell'anno 2010" Treccani, Roma, Istituto dell'Enciclopedia Italiana 2010, pp. 207-320

    Structured Knowledge Representation for Image Retrieval

    Get PDF
    We propose a structured approach to the problem of retrieval of images by content and present a description logic that has been devised for the semantic indexing and retrieval of images containing complex objects. As other approaches do, we start from low-level features extracted with image analysis to detect and characterize regions in an image. However, in contrast with feature-based approaches, we provide a syntax to describe segmented regions as basic objects and complex objects as compositions of basic ones. Then we introduce a companion extensional semantics for defining reasoning services, such as retrieval, classification, and subsumption. These services can be used for both exact and approximate matching, using similarity measures. Using our logical approach as a formal specification, we implemented a complete clientserver image retrieval system, which allows a user to pose both queries by sketch and queries by example. A set of experiments has been carried out on a testbed of images to assess the retrieval capabilities of the system in comparison with expert users ranking. Results are presented adopting a well-established measure of quality borrowed from textual information retrieval

    Ma gli intellettuali tacciono scoraggiati

    Get PDF


    full texts


    metadata records
    Updated in last 30 days.
    Unitus DSpace is based in IT
    Access Repository Dashboard
    Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇