Sökning: "Jena"

Visar resultat 1 - 5 av 21 uppsatser innehållade ordet Jena.

  1. 1. Evaluating a new hydraulic implementation in LPJ-GUESS for three sites in north Europe

    Master-uppsats, Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Författare :Carl Holmquist; [2023]
    Nyckelord :Physical Geography and Ecosystem analysis; LPJ-GUESS; drought; sensitivity analysis; evapotranspiration; gross primary production; hydraulic parameters; boreal forest.; Earth and Environmental Sciences;

    Sammanfattning : Drought is projected to increase in frequency and intensity and impacts trees with increased water stress and increased mortality rate. Water stresses can cause hydraulic failure-related mortality or carbon starvation due to tree species having different strategies to deal with water stresses. LÄS MER

  3. 2. Multitask Convolutional Neural Network Emulators for Global Crop Models - Supervised Deep Learning in Large Hypercubes of Non-IID Data

    Master-uppsats, Lunds universitet/Matematisk statistik

    Författare :Amanda Nilsson; [2020]
    Nyckelord :Multitask Learning; Convolutional Neural Network CNN ; Branched Neural Network; Dynamic Global Vegetation Models DGVM ; Automated Feature Extraction; Feature Importance; Supervised Machine Learning; Emulator; Surrogate Model; Response Surface Model; Approximation Model; Metamodeling; Model Composition; Regularization; Robustness; Hyperparameter Optimization; Mathematics and Statistics;

    Sammanfattning : The aim of this thesis is to establish whether a neural network (NN) can be used for emulation of simulated global crop production - retrieved from the computationally demanding dynamic global vegetation model (DGVM) Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS). It has been devoted to elaboration with various types of neural network architectures: Branched NNs capable of processing inputs of mixed data types; Convolutional Neural Network (CNN) architectures able to perform automated temporal feature extraction of the given weather time series; simpler fully connected (FC) structures as well as Multitask NNs. LÄS MER

  4. 3. Comparison of geospatial support in RDF stores: Evaluation for ICOS Carbon Portal metadata

    Master-uppsats, Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Författare :Amir Raza; [2019]
    Nyckelord :Geography; Geographical Information Systems GIS ; GeoSPARQL; Geospatial query language; RDF stores; Java Programming; RDF4J; Jena; Virtuoso; Stardog; GraphDB; Earth and Environmental Sciences; Technology and Engineering;

    Sammanfattning : The evolution of World Wide Web (WWW) into semantic web is happening with the aid of standards like Resource Description Framework (RDF), SPARQL and a few others from World Wide Web Consortium (W3C). Over the years, semantic data management technologies have been introduced as software platforms commonly known as RDF stores. LÄS MER

  5. 4. Implications of a dynamic vertical root distribution for modelled water and carbon fluxes across selected ecosystems : incorporating a novel rooting scheme into LPJ-GUESS

    Master-uppsats, Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

    Författare :Lasse Keetz; [2019]
    Nyckelord :Physical Geography and Ecosystem Analysis; Ecosystem Modelling; LPJ-GUESS; Vertical Root Distribution; Dynamic Root Distribution; Carbon and Water Fluxes; Earth and Environmental Sciences;

    Sammanfattning : Roots play a key role in terrestrial carbon and water cycles, and therefore for the global climate system. They mediate plant evapotranspiration, influence photosynthetic processes and are responsible for atmospheric carbon transport into the pedosphere. Fine roots, in particular, are chiefly regulating water and nutrient uptake. LÄS MER

  7. 5. Supply Chain Transparency of Certified and Conventional Businesses : A case of Coffee Industry in Colombia

    Master-uppsats, Högskolan i Halmstad/Akademin för ekonomi, teknik och naturvetenskap

    Författare :Marcela Morales; Eini Inha; [2018]
    Nyckelord :Supply chain transparency; certified businesses; conventional businesses; coffee industry; Colombia;

    Sammanfattning : Companies including their stakeholders, investors and nongovernmental organizations have an increasing interest regarding the information about the impact of their products in terms of who, how and where the products were produced (Kashmanian, 2017). A qualitative field study including interviews and observations was conducted in order to carry out the comparison of Supply Chain Transparency (SCT) between certified and conventional businesses. LÄS MER