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Planning of commercial thinnings using machine learning and airborne Lidar data / Tauri Arumäe in Forests, vol 13 n° 2 (February 2022)  

Public [article]  inForests > vol 13 n° 2 (February 2022) . - n° 206 Titre : Planning of commercial thinnings using machine learning and airborne Lidar data Type de document : Article/Communication Auteurs : Tauri Arumäe, Auteur ; Mait Lang, Auteur ; Allan Sims, Auteur ; et al., Auteur Année de publication : 2022 Article en page(s) : n° 206 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] apprentissage automatique [Termes IGN] classification par forêts d'arbres décisionnels [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] éclaircie (sylviculture) [Termes IGN] Estonie [Termes IGN] gestion forestière [Termes IGN] inventaire forestier (techniques et méthodes) [Termes IGN] modèle linéaire [Termes IGN] planification [Termes IGN] semis de points Résumé : (auteur) The goal of this study was to predict the need for commercial thinning using airborne lidar data (ALS) with random forest (RF) machine learning algorithm. Two test sites (with areas of 14,750 km2 and 12,630 km2) were used with a total of 1053 forest stands from southwestern Estonia and 951 forest stands from southeastern Estonia. The thinnings were predicted based on the ALS measurements in 2019 and 2017. The two most important ALS metrics for predicting the need for thinning were the 95th height percentile and the canopy cover. The prediction accuracy based on validation stands was 93.5% for southwestern Estonia and 85.7% for southeastern Estonia. For comparison, the general linear model prediction accuracy was less for both test sites—92.1% for southwest and 81.8% for southeast. The selected important predictive ALS metrics differed from those used in the RF algorithm. The cross-validation of the thinning necessity models of southeastern and southwestern Estonia showed a dependence on geographic regions. Numéro de notice : A2022-122 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.3390/f13020206 Date de publication en ligne : 29/01/2022 En ligne : https://doi.org/10.3390/f13020206 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99674 [article]

Consolidation of crowd-sourced geo-ragged data for parameterized travel recommendations / Ago Luberg (2021)  

Public Titre : Consolidation of crowd-sourced geo-ragged data for parameterized travel recommendations Type de document : Thèse/HDR Auteurs : Ago Luberg, Auteur ; Tanel Tammet, Directeur de thèse Editeur : Tallinn [Estonia] : Tallinn University of Technology Année de publication : 2021 Importance : 159 p. Format : 21 x 30 cm Note générale : bibliographie Dissertation accepted for the defence of the degree of Doctor of Philosophy in Computer Science Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] apprentissage automatique [Termes IGN] base de données [Termes IGN] conception orientée utilisateur [Termes IGN] données localisées des bénévoles [Termes IGN] extraction de données [Termes IGN] géoréférencement [Termes IGN] point d'intérêt [Termes IGN] Riga [Termes IGN] site wiki [Termes IGN] système de recommandation [Termes IGN] Tallinn [Termes IGN] taxinomie [Termes IGN] tourisme Résumé : (auteur) The research covered in this thesis is focused on different aspects of the task of creating automated recommendations for tourism, focusing mostly on places of interest like beautiful views, architectural landmarks, charming areas etc. A significant amount of work has been spent on designing and developing actual recommender systems - Sightsplanner, Sightsmap and the automated recommender of Visit Estonia - and their data harvesting methods in order to create a platform for showing the feasibility of the new methods designed and experimented with. The main results of our research are split between three subfields: • Knowledge engineering: we have shown how to formalize fuzzy and uncertain POI categories along with suitable ontologies and reasoner-based algorithms for object matching and score calculation in a real-life context of actual POI-s, available data and easily expressable user preferences. • Machine learning: we have designed a learnable detection system for detecting duplicate POIs from different databases, usable for cross- category, cross-language and cross-city datasets. • We show that learning on Tallinn eateries improved the algorithm parameters to such a degree that on Riga data containing also museums and galleries it gave us 98% accuracy versus 85% accuracy achieved by tuning the algorithm parameters manually. • Knowledge extraction: we have designed an algorithm for high-quality keyword extraction from short crowd-sourced POI descriptions in different languages, able to find a suitable name and to add suitable types to the POI. Our clusterization algorithm is able to merge the POIs based on the extracted data: on the Panoramio and Wikipedia data about U.K. and French locations it was able to find 56% of Wikipedia objects from the textual titles/annotations of Panoramio pictures in the area. Note de contenu : 1- Introduction 2- Related work 3- Involvement in recommender projects 4- Data acquisition and information extraction 5- Data deduplication (using machine learning) 6- Location category and name detection 7- Data storage and object score calculation 8- Conclusions 9- Future work Numéro de notice : 28600 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Thèse étrangère Note de thèse : PhD Thesis : Computer Science : Tallinn University of Technology : 2021 DOI : 10.23658/taltech.23/2021 En ligne : https://doi.org/10.23658/taltech.23/2021 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99407

Impact of deadwood decomposition on soil organic carbon sequestration in Estonian and Polish forests / Ewa Blonska in Annals of Forest Science [en ligne], Vol 76 n° 4 (December 2019)  

Public [article]  inAnnals of Forest Science [en ligne] > Vol 76 n° 4 (December 2019) Titre : Impact of deadwood decomposition on soil organic carbon sequestration in Estonian and Polish forests Type de document : Article/Communication Auteurs : Ewa Blonska, Auteur ; Jaroslaw Lasota, Auteur ; Arvo Tullus, Auteur ; et al., Auteur Année de publication : 2019 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] bois mort [Termes IGN] déchet organique [Termes IGN] Estonie [Termes IGN] forêt boréale [Termes IGN] forêt tempérée [Termes IGN] Pologne [Termes IGN] teneur en carbone [Vedettes matières IGN] Ecologie forestière Résumé : (auteur) Key message : The deadwood of different tree species with different decomposition rates affects soil organic carbon sequestration in Estonian and Polish forests. In warmer conditions (Poland), the deadwood decomposition process had a higher rate than in cooler Estonian forests. Soil organic matter fractions analysis can be used to assess the stability and turnover of organic carbon between deadwood and soil in different experimental localities. Context : Deadwood is an important element of properly functioning forest ecosystem and plays a very important role in the maintenance of biodiversity, soil fertility, and carbon sequestration. Aims : The main aim was to estimate how decomposition of deadwood of different tree species with different decomposition rates affects soil organic carbon sequestration in Estonian and Polish forests. Methods : The investigation was carried out in six forests in Poland (51° N) and Estonia (58° N). The study localities differ in their mean annual air temperature (of 2 °C) and the length of the growing season (of 1 month). The deadwood logs of Norway spruce (Picea abies (L.) Karst.), common aspen (Populus tremula L.), and silver birch (Betula pendula Roth) were included in the research. Logs in three stages of decomposition (III–V) were selected for the analysis. Results : There were differences in the stock of soil organic carbon in two experimental localities. There was a higher soil carbon content under logs and in their direct vicinity in Polish forests compared to those in the cooler climate of Estonia. Considerable differences in the amount of soil organic matter were found. The light fraction constituted the greatest quantitative component of organic matter of soils associated with deadwood. Conclusion : A higher carbon content in surface soil horizons as an effect of deadwood decomposition was determined for the Polish (temperate) forests. More decomposed deadwood affected soil organic matter stabilization more strongly than less decayed deadwood. This relationship was clearer in Polish forests. Higher temperatures and longer growing periods primarily influenced the increase of soil organic matter free light fraction concentrations directly under and in close proximity to logs of the studied species. The slower release of deadwood decomposition products was noted in Estonian (hemiboreal) forests. The soil organic matter mineral fraction increased under aspen and spruce logs at advanced decomposition in Poland. Numéro de notice : A2019-530 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-019-0889-9 Date de publication en ligne : 29/10/2019 En ligne : https://doi.org/10.1007/s13595-019-0889-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94118 [article]

Mapping changes of residence with passive mobile positioning data : the case of Estonia / Pilleriine Kamenjuk in International journal of geographical information science IJGIS, vol 31 n° 7-8 (July - August 2017)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 31 n° 7-8 (July - August 2017) . - pp 1425 - 1447 Titre : Mapping changes of residence with passive mobile positioning data : the case of Estonia Type de document : Article/Communication Auteurs : Pilleriine Kamenjuk, Auteur ; Anto Aasa, Auteur ; Jaanus Sellin, Auteur Année de publication : 2017 Article en page(s) : pp 1425 - 1447 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] Estonie [Termes IGN] géovisualisation [Termes IGN] habitat individuel [Termes IGN] migration pendulaire [Termes IGN] mobilité [Termes IGN] surveillance [Termes IGN] téléphonie mobile [Termes IGN] trace GPS Résumé : (Auteur) Similar to every process involving quantitative research, the study of migration heavily depends on the data available for analysis. The available movement data limit the type of questions that can be asked, and as a result, certain aspects of human spatial mobility have yet to be examined. The development of information and communication technologies and their widespread adoption offers new datasets, methods and interpretations that make it possible to study social processes at a new level. For example, mobile positioning data can aid in overcoming certain constraints embedded in traditional data sources (such as censuses or questionnaires) for study of the connections between daily mobility and change of residence. This study presents a framework for mapping changes of residence using data from passive mobile positioning and an anchor point model to better understand the limits of these methods and their contribution to understanding long-term mobility. The study concludes that the most important considerations in monitoring change of residence using passive mobile position data include the continuity of the time-series data, the varying structure of the mobile tower network and the diversified nature of human mobility. The fine spatial and temporal granularities of passive mobile positioning data allow us to study human movement at a detailed scale. Numéro de notice : A2017-307 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/13658816.2017.1295308 En ligne : http://dx.doi.org/10.1080/13658816.2017.1295308 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85354 [article]

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Effects of environmental factors on the species richness, composition and community horizontal structure of vascular plants in Scots pine forests on fixed sand dunes / Mari Tilk in Silva fennica, vol 51 n° 3 (2017)  

Public [article]  inSilva fennica > vol 51 n° 3 (2017) Titre : Effects of environmental factors on the species richness, composition and community horizontal structure of vascular plants in Scots pine forests on fixed sand dunes Type de document : Article/Communication Auteurs : Mari Tilk, Auteur ; Tea Tullus, Auteur ; Katri Ots, Auteur Année de publication : 2017 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] biodiversité [Termes IGN] dune [Termes IGN] Estonie [Termes IGN] facteur édaphique [Termes IGN] microhabitat [Termes IGN] Pinus sylvestris [Vedettes matières IGN] Ecologie forestière Résumé : (auteur) Different environmental factors were studied to determine which factors influence the species richness, composition and structure of vascular plants in Pinus sylvestris L. forests in a fixed dune landscape in south-western Estonia. In addition to site topographic factors, different environmental parameters were investigated. Thirty-four vascular plant species were recorded in 232 quadrats. The most abundant species was Vaccinium vitis-idaea L., which was in 82.8% of quadrats, followed by Vaccinium myrtillus L. (74.1%), Melampyrum pratense L. (71.1%) and Deschampsia flexuosa (L.) Trin. (69.8%). The multiple response permutation procedure (MRPP) showed considerable differences in species composition at the bottoms of dunes compared with that on the slopes and at the tops of dunes. Indicator species analysis (ISA) determined species exhibited characteristics specific to zone: V. myrtillus had the highest indicator value at the bottoms of dunes; Calluna vulgaris L., at the tops. Soils were Haplic Podzols, and the presence of humus horizon depended on zone. Soil conditions on the dunes were variable and site specific, in general, soils at the bottoms of the dunes were more acidic and moist compared with those of the slopes and tops of the dunes, and the nutrient content decreased toward the dune tops. According to non-metric multidimensional scaling (NMDS) and linear mixed model analyses, species coverage, composition and richness were controlled by site-specific factors such as absolute height, location and aspect of the quadrat on the dune; soil nitrogen, potassium and phosphorus contents; soil pH and moisture; light conditions; and the thickness of the litter horizon. Numéro de notice : A2017-647 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.14214/sf.6986 En ligne : https://doi.org/10.14214/sf.6986 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=87005 [article]

Plant community mycorrhization in temperate forests and grasslands: relations with edaphic properties and plant diversity / Maret Gerz in Journal of vegetation science, vol 27 n° 1 (January 2016)  

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Préparation et conception de données 3D sur la ville de Tallinn / Sylvain Jourdana (2016) 

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Habitat directive forest type western taiga (*9010) in Estonia : the first description of stand structure according to mapping and monitoring data / Anneli Palo in Baltic forestry, vol 21 n° 1 ([01/02/2015])  

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Les industries baltes du bois en plein essor / Al Arter in Le Bois International : l'officiel du bois [édition verte], vol 2008 n° 17 (3 et 10 mai 2008)

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Geographic information and the enlargement of the European Union / Massimo Craglia (2001)

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Gravity measurements of Estonia / H. Sildvee (1998)

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Parliamentary libraries and research services in central and eastern Europe / W.H. Robinson (1998)

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Coordinate systems, GPS and the geoid / M. Vermeer (1995)

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Latest developments in the computation of regional Geoids / M. Vermeer (1995)

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A fast delivery GPS-gravimetric geoid for Estonia / M. Vermeer (1994)

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