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The following results are related to Rural Digital Europe. Are you interested to view more results? Visit OpenAIRE - Explore.
32 Research products, page 1 of 4

  • Rural Digital Europe
  • Publications
  • 2013-2022
  • Open Access
  • DSpace at Tartu University Library

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  • Open Access English
    Authors: 
    Mass, Jakob;
    Country: Estonia

    Värkvõrk, ehk Asjade Internet (Internet of Things, lüh IoT) edendab lahendusi nagu nn tark linn, kus meid igapäevaselt ümbritsevad objektid on ühendatud infosüsteemidega ja ka üksteisega. Selliseks näiteks võib olla teekatete seisukorra monitoorimissüsteem. Võrku ühendatud sõidukitelt (nt bussidelt) kogutakse videomaterjali, mida seejärel töödeldakse, et tuvastada löökauke või lume kogunemist. Tavaliselt hõlmab selline lahendus keeruka tsentraalse süsteemi ehitamist. Otsuste langetamiseks (nt milliseid sõidukeid parasjagu protsessi kaasata) vajab keskne süsteem pidevat ühendust kõigi IoT seadmetega. Seadmete hulga kasvades võib keskne lahendus aga muutuda pudelikaelaks. Selliste protsesside disaini, haldust, automatiseerimist ja seiret hõlbustavad märkimisväärselt äriprotsesside halduse (Business Process Management, lüh BPM) valdkonna standardid ja tööriistad. Paraku ei ole BPM tehnoloogiad koheselt kasutatavad uute paradigmadega nagu Udu- ja Servaarvutus, mis tuleviku värkvõrgu jaoks vajalikud on. Nende puhul liigub suur osa otsustustest ja arvutustest üksikutest andmekeskustest servavõrgu seadmetele, mis asuvad lõppkasutajatele ja IoT seadmetele lähemal. Videotöötlust võiks teostada mini-andmekeskustes, mis on paigaldatud üle linna, näiteks bussipeatustesse. Arvestades IoT seadmete üha suurenevat hulka, vähendab selline koormuse jaotamine vähendab riski, et tsentraalne andmekeskust ülekoormamist. Doktoritöö uurib, kuidas mobiilsusega seonduvaid IoT protsesse taoliselt ümber korraldada, kohanedes pidevalt muutlikule, liikuvate seadmetega täidetud servavõrgule. Nimelt on ühendused katkendlikud, mistõttu otsuste langetus ja planeerimine peavad arvestama muuhulgas mobiilseadmete liikumistrajektoore. Töö raames valminud prototüüpe testiti Android seadmetel ja simulatsioonides. Lisaks valmis tööriistakomplekt STEP-ONE, mis võimaldab teadlastel hõlpsalt simuleerida ja analüüsida taolisi probleeme erinevais realistlikes stsenaariumites nagu seda on tark linn. The Internet of Things (IoT) promotes solutions such as a smart city, where everyday objects connect with info systems and each other. One example is a road condition monitoring system, where connected vehicles, such as buses, capture video, which is then processed to detect potholes and snow build-up. Building such a solution typically involves establishing a complex centralised system. The centralised approach may become a bottleneck as the number of IoT devices keeps growing. It relies on constant connectivity to all involved devices to make decisions, such as which vehicles to involve in the process. Designing, automating, managing, and monitoring such processes can greatly be supported using the standards and software systems provided by the field of Business Process Management (BPM). However, BPM techniques are not directly applicable to new computing paradigms, such as Fog Computing and Edge Computing, on which the future of IoT relies. Here, a lot of decision-making and processing is moved from central data-centers to devices in the network edge, near the end-users and IoT sensors. For example, video could be processed in mini-datacenters deployed throughout the city, e.g., at bus stops. This load distribution reduces the risk of the ever-growing number of IoT devices overloading the data center. This thesis studies how to reorganise the process execution in this decentralised fashion, where processes must dynamically adapt to the volatile edge environment filled with moving devices. Namely, connectivity is intermittent, so decision-making and planning need to involve factors such as the movement trajectories of mobile devices. We examined this issue in simulations and with a prototype for Android smartphones. We also showcase the STEP-ONE toolset, allowing researchers to conveniently simulate and analyse these issues in different realistic scenarios, such as those in a smart city. https://www.ester.ee/record=b5525514

  • Open Access English
    Authors: 
    Montibeller, Bruno;
    Country: Estonia

    Forests are strongly impacted by human activities. While the deforestation is very likely the most common examples of human impact on forested areas, the remaining standing forests are susceptible to other types of direct or indirect forest degradation by humans. The direct human-induced impacts can be exemplified by forest fragmentation or selective logging while the indirect human-induced impacts can be related to the changes in the ecosystem services (e.g., carbon and water cycling) induced by anthropogenic climate change. The aim of this thesis was to evaluate two processes related to forest degradation: (i) fragmentation of tropical forest cover in the Brazilian Amazon and (ii) changes in forest evapotranspiration over/across the Baltic countries and the carbon cycle in undisturbed forest areas across Europe. Satellite derived data and spatial analyses were used to assess the impacts of forest degradation in these three different case studies. The results of this thesis showed that although the anti-deforestation initiatives have played an important role in reducing deforestation in the Brazilian Amazon region, the forest fragmentation has increased mainly because of the decrease in the size of forest loss patches and the spatial shift into areas previously isolated areas. Hence, more forest areas are potentially being degraded because of the edge effects (e.g., tree mortality) caused by the fragmentation. For the Baltic region, the results indicated an intensification of the evapotranspiration rates over undisturbed forest areas. The intensification occurred mainly during spring and early autumn months because of the longer growing season induced by the increasing temperatures during these periods. Changes in the climate patterns were also the potential cause for changes in the carbon assimilation rates over the European forests. Approximately 25% of the undisturbed European forests showed reduced total carbon assimilation. That shows the vulnerability and incapacity of certain forest areas to act as carbon sink. Metsaökosüsteemid võivad siduda kuni 12% inimtekkelisest süsihappegaasist ning tagastada atmosfääri kuni 40% kohalikest sademetest. Seetõttu on metsaökosüsteemidel oluline roll süsihappegaasi emissioonide vähendamisel ja veeringe reguleerimisel. Samal ajal väheneb metsade pindala ning metsad degradeeruvad läbi killustumise ning nende süsiniku- ja veeringe reguleerimise võime võib väheneda kliimamuutuste tõttu. Käesoleva doktoritöö eesmärgiks oli hinnata kahte metsade degradeerumisega seotud protsessi: (1) troopilise vihmametsa killustumist Brasiilia Amasoonias ja (2) muutuseid evapotranspiratsioonis ja süsinikuringes Baltikumi ja Eurooma muutumatuna püsinud metsamassiivides. Käesoleva doktoritöö tulemused näitasid, et kuigi Brasiilias on metsatustumise vastased poliitikad vähendanud metsade raadamist, siis samal ajal on suurenenud metsade killustumine, sest raiutakse väiksemate eraldiste kaupa ja liikudes endiselt varem raadamata aladele. Killustunud metsas on rohkem metsaserva, kust on süsinikukaod suuremad nii leostumise kui ka gaasilise emissioonina. Baltikumis leiti, et pikem taimekasvuperiood on suurendanud evapotranspiratsiooni kevadel ja sügisel, kuid samal ajal on suvel evapotranspiratsioon mõnedes piirkondades vähenenud. Kuigi evapotranspiratsiooni suurenemisel ei ole metsade ökosüsteemile otseselt negatiivset mõju, siis võib sellel olla ebasoovitav mõju regiooni veeringele, sest suurenenud evapotranspiratsioon suurendab tõenäosust, et suveperioodil on mullas vähem vett, mis omakorda suurendab põuaohtu. Lisaks selgus, et neljandikus Euroopa muutumatuna püsinud metsamassiivides on süsiniku sidumine vähenenud. Vähenenud süsiniku sidumisega metsamassiivid paiknesid üle kogu Euroopa ning hõlmasid erinevaid metsatüüpe. Kliimamuutuste mõjul võib metsade süsiniku sidumine väheneda veelgi rohkem, mis seab kahtluse alla varasemalt eeldatud metsade võimekuse leevendada kliimamuutuste mõjusid. Väitekirja elektrooniline versioon ei sisalda publikatsioone https://www.ester.ee/record=b5519495

  • Open Access English
    Authors: 
    Vahter, Tanel;
    Country: Estonia

    This doctoral thesis provides a deeper understanding of the ecology of soil fungi that form mycorrhizas in arable landscapes. These fungi provide plants with much needed soil nutrients and are therefore a vital part of sustainable food production. One of the central aims was to understand how the common agricultural practices used in the fields affect these key fungi. In our studies we found that much like in the rest of Europe, there are large differences in the diversity of mycorrhizal fungi in arable field soils. Differences in mycorrhizal fungal richness between the most and least diverse fields were sixfold. The major factors decreasing mycorrhizal fungal diversity were the use of synthetic fertilizers and pesticides but also biodiversity impoverished agricultural landscapes. In addition, we learned that temporary grasslands within the crop rotations have important implications for sustaining soil fungal biodiversity. Furthermore, we found that the crop varieties sown can have an impact on mycorrhizal fungi, with some older varieties faring better in organically managed soils than newer breeds. Although the plants’ affinity to mycorrhizal fungi was not clearly dependant on the era a variety was bred, it does show that we should bear mycorrhizal associations in mind when breeding crops of the future. We also experimented with creating diverse vegetation assemblages in biodiversity impoverished landscapes, using depleted oil-shale quarries as a model system. We used native plants and sowed them onto the restoration sites together with the mycorrhizal fungi they naturally grow with. Using this methodology, we were able to bring dosens of plant species into a former biodiversity desert, highlighting the possibilities of restoring biodiversity hot-spots also in other areas. To conclude, we emphasize that safeguarding the biodiversity of vital mycorrhizal fungi is possible even with the measures available to farmers today. More organic fertilizers with diverse crop rotations for disease and weed control, accompanied by the biodiversity support of diverse landscapes is something that would pave the way for sustainable food production. Doktoritöö käigus uuriti taimede ja seente vahelist vastastikku kasulikku kooselu, mükoriisat, moodustavate mullaseente ökoloogiat põllumajandusmaastikes. Kuna nende seente abil saavad taimed mullast vajaminevaid toitaineid, on nad oluline osa mulla elustikust ning panustavad ka põllumajanduse jätkusuutlikkusse. Töö üks põhieesmärke oli uurida, kuidas levinud põlluharimise praktikad mükoriisaseeni mõjutavad ning millised praktikad võiksid nende elurikkust suurendada. Uuringutes leidsime, et sarnaselt Lääne-Euroopaga on ka Eestis olenevalt põlluharimise viisidest mükoriisaseente elurikkuses suured erinevused – mitmekesisemate ja vaesemate põldude mükoriisaseente liigirikkuse vahe oli koguni kuuekordne. Olulisteks negatiivseteks teguriteks olid sünteetiliste väetiste ja pestitsiidide kasutamine, kuid positiivselt mõjusid orgaaniliste väetiste kasutamine ja maastikuelementide rohkus. Lisaks saime teada, et lühiajaliste rohumaade lisamine külvikorda soodustab mullaseeni ning külvikorra planeerimisel tasuks mõelda kasvatatavate sortide valiku peale. Näiteks selgus, et mõned ajaloolised nisusordid kasvavad paremini koos mahetootmise põllu mullast pärit seentega, samas kui mõni kaasaegne sort jällegi intensiivtootmise mulla seentega. Selle teadmise baasilt oleks võimalik tulevikus aretada näiteks mükoriisasõbralikke sorte nii mahe- kui tavaviljelusse. Lisaks eksperimenteerisime ka liigirikaste taimekoosluste taastamisega, luues liigivaestesse põlevkivikarjääridesse mükoriisaseente abiga kõigest mõne aastaga rohelised niidud. Sama metoodikat kasutades võiks tekitada elurikkuse tugipunkte ka intensiivselt majandatud põllumajandusmaastikesse, kus taimede, putukate ja mükoriisaseente elustik põllumajandustootjale kasu saaks tuua. Seega, kasutades rohkem orgaanilisi väetisi ja tõrjudes haiguseid ning kahjureid mitmekesise külvikorraga saab luua mükoriisaseeni soodustavad tingimused. Lisades maastikesse veel uusi ja hoides olemasolevaid elurikkuse tugipunkte, võiksime olla eeskujuks oma kodukandi kõrge elurikkuse ja sellega arvestava toidutootmisega. Väitekirja elektrooniline versioon ei sisalda publikatsioone https://www.ester.ee/record=b5449439

  • Open Access English
    Authors: 
    Draheim, Dirk; Krimmer, Robert; Tammet, Tanel;
    Publisher: Springer, Berlin, Heidelberg
    Country: Estonia

    The \digital transformation" is perceived as the key enabler for increasing wealth and well-being by politics, media and the citizens alike. In the same vein, digital government steadily receives more and more attention. Digital government gives rise to complex, large-scale state-level system landscapes consisting of many players and technological systems { and we call such system landscapes digital government ecosystems. In this paper, we systematically approach the state-level architecture of digital government ecosystems.We will discover the primacy of the state's institutional design in the architecture of digital government ecosystems, where Williamson's institutional analysis framework supports our considerations as theoretical background. Based on that insight, we will establish the notion of data governance architecture, which links data assets with accountable organizations. Our investigation results into a digital government architecture framework that can help in large-scale digital government design e_orts through (i) separation of concerns in terms of appropriate categories, and (ii) a better assessment of the feasibility of envisioned digital transformations. With its focus on data, the proposed framework perfectly _ts the current discussion on moving from ICT-driven to data-centric digital government.

  • Open Access
    Authors: 
    Alexander Kmoch; Arno Kanal; Alar Astover; Ain Kull; Holger Virro; Aveliina Helm; Meelis Pärtel; Ivika Ostonen; Evelyn Uuemaa;
    Publisher: Copernicus GmbH
    Country: Estonia
    Project: EC | GLOMODAT (795625)

    To understand, model, and predict landscape evolution, ecosystem services, and hydrological processes, the availability of detailed observation-based soil data is extremely valuable. For the EstSoil-EH dataset, we synthesized more than 20 eco-hydrological variables on soil, topography, and land use for Estonia (https://doi.org/10.5281/zenodo.3473289, Kmoch et al., 2019a) as numerical and categorical values from the original Soil Map of Estonia, the Estonian 5 m lidar DEM, Estonian Topographic Database, and EU-SoilHydroGrids layers. The Soil Map of Estonia maps more than 750 000 soil units throughout Estonia at a scale of 1:10 000 and forms the basis for EstSoil-EH. It is the most detailed and information-rich dataset for soils in Estonia, with 75 % of mapped units smaller than 4.0 ha, based on Soviet-era field mapping. For each soil unit, it describes the soil type (i.e. soil reference group), soil texture, and layer information with a composite text code, which comprises not only the actual texture class, but also classifiers for rock content, peat soils, distinct compositional layers, and their depths. To use these as eco-hydrological process properties in modelling applications we translated the text codes into numbers. The derived parameters include soil layering, soil texture (clay, silt, and sand contents), coarse fragments, and rock content of the soil layers within the soil profiles. In addition, we aggregated and predicted physical variables related to water and carbon cycles (bulk density, hydraulic conductivity, organic carbon content, available water capacity). The methodology and dataset developed will be an important resource for the Baltic region, but possibly also for all other regions where detailed field-based soil mapping data are available. Countries like Lithuania and Latvia have similar historical soil records from the Soviet era that could be turned into value-added datasets such as the one we developed for Estonia.

  • Open Access English
    Authors: 
    Hartmann, Dennis;
    Publisher: Tartu Ülikool
    Country: Estonia
  • Open Access English
    Authors: 
    Kustavus, Allan;
    Publisher: Tartu Ülikool
    Country: Estonia

    Autonomous robots are utilized in a wide range of domains, combining a large number of resources like sensors, actuators and algorithms to form a self-acting robotic system. Tools, such as ROS and TeMoto, have been developed to allow for handling and managing of resources composing such systems. While TeMoto is meant to handle dynamic and changing situations the current implementation of its Resource Registrar, a core TeMoto component tasked with allocating, deallocating and tracking of resources, is tightly coupled to ROS, making it difficult to modify and improve. As a result of this thesis, the Resource Registrar (RR) of TeMoto was completely redesigned to be extendable to other robotic middleware, such as ROS2, and to improve TeMoto’s robustness with features, e.g., full recovery of the RR, that were unattainable with the previous design.

  • Open Access English
    Authors: 
    Milyakina, Alexandra;
    Country: Estonia

    Despite the common concern, young people today are engaging with literature more than ever, albeit in the ways that are not always recognized. Literary education in the digital age implies navigating a heterogeneous world of metatexts in different media and integrating them into a coherent whole. Rather than reading the original versions of literary texts, people often gain information from elsewhere, i.e. by watching film adaptations, scrolling through memes, playing video games, or reading comments on Youtube. In contrast to printed books that are mostly verbal, linear and created by a single author, digital texts are becoming increasingly multimodal, non-linear and collaborative. Apart from a qualitative and quantitative change in the nature of texts, digitalization entails a shift in social relations: producers and consumers merge into prosumers, while teachers turn into knowledge facilitators rather than all-knowing others. While the current situation can be certainly considered as a moment of explosion, this work mostly focuses on its opposite – the stage of gradual development. The thesis explores the transformation of literary education from different angles. At first, it discusses the applicability of different forms of texts and practices to teaching literature, such as digital and film adaptations, games, and project development workshops. Secondly, it synthesizes the ideas of the Tartu-Moscow Semiotic School and the multimodal approach, in order to analyze literary education in the context of cultural autocommunication as well as through the prism of social relations. Finally, it suggests pedagogical and technological solutions for bridging the gap between formal literary education and vernacular digital practices. The thesis aims to answer research questions by means of experimentation rather than by a theoretical argument: the findings are based on the empirical material gathered while working on the Education on Screen project. Vaatamata levinud arvamusele on noorte inimeste kirjanduselu aktiivsem kui kunagi varem. Kirjandusega suheldakse lihtsalt viisidel, mis ei pruugi alati laiemat tunnustamist leida. Digiajastul hõlmab kirjandusharidus erinevates meediumites loodud metatekstide mitmekesises võrgustikus navigeerimist ja nende pinnalt terviku integreerimist. Algtekstide esialgsel kujul lugemise asemel hangitakse selle kohta teadmisi nt ekraniseeringute, meemide, videomängude või isegi YouTube’i kommentaaride vahendusel. Verbaalsele, lineaarsele ja üksikautorluses trükiraamatule vastukaaluks on digitaalsed tekstid multimodaalsed, mittelineaarsed ja koosloomelised. Tekstide kvantitatiivsete ja kvalitatiivsete omaduste muutuste kõrval on digitaliseerumine kaasa toonud nihked ka kirjandusharidust puudutavates sotsiaalsetes suhetes - loojad ja vastuvõtjad segunevad, kõike teadvatest õpetajatest saavad juhendajad iseseisvas teadmiste omandamise protsessis. Sellist olukorda võib vaadelda kultuurilise plahvatushetkena, kuid käesolev töö keskendub vastasküljele -- pidevale muutusele. Väitekiri käsitleb kirjandushariduse muutumist erinevate nurkade alt. Esiteks vaadeldakse eelnimetatud metatekstide rakendatavust kirjanduse õpetamisel. Teiseks sünteesitakse Tartu-Moskva semiootikakoolkonna ning multimodaalsuse uuringuid analüüsimaks kirjandusharidust nii kultuurilise autokommunikatsiooni kontekstis kui läbi sotsiaalsete suhete prisma. Viimaseks pakutakse välja pedagoogilisi ja tehnoloogilisi lahendusi, et ületada formaalse kirjandushariduse ja igapäevaste digitaalsete praktikate vahelist lõhet. Väitekirjas lähenetakse uurimisküsimustele eksperimentaalselt ning töö aluseks olev empiiriline materjal pärineb autori osalusel valminud digitaalselt õppeplatvormilt Haridus Ekraanil ja selle kasutamiskogemustest. Väitekirja elektrooniline versioon ei sisalda publikatsioone https://www.ester.ee/record=b5383228

  • Open Access
    Authors: 
    Evelyn Uuemaa; Sander Ahi; Bruno Montibeller; Merle Muru; Alexander Kmoch;
    Publisher: MDPI AG
    Country: Estonia
    Project: EC | GLOMODAT (795625)

    Freely available global digital elevation models (DEMs) are important inputs for many research fields and applications. During the last decade, several global DEMs have been released based on satellite data. ASTER and SRTM are the most widely used DEMs, but the more recently released, AW3D30, TanDEM-X and MERIT, are being increasingly used. Many researchers have studied the quality of these DEM products in recent years. However, there has been no comprehensive and systematic evaluation of their quality over areas with variable topography and land cover conditions. To provide this comparison, we examined the accuracy of six freely available global DEMs (ASTER, AW3D30, MERIT, TanDEM-X, SRTM, and NASADEM) in four geographic regions with different topographic and land use conditions. We used local high-precision elevation models (Light Detection and Ranging (LiDAR), Pleiades-1A) as reference models and all global models were resampled to reference model resolution (1m). In total, 608 million 1x1 m pixels were analyzed. To estimate the accuracy, we generated error rasters by subtracting each reference model from the corresponding global DEM and calculated descriptive statistics for this difference (e.g., median, mean, root-mean-square error (RMSE)). We also assessed the vertical accuracy as a function of the slope, slope aspect, and land cover. We found that slope had the strongest effect on DEM accuracy, with no relationship for slope aspect. The AW3D30 was the most robust and had the most stable performance in most of the tests and is therefore the best choice for an analysis of multiple geographic regions. SRTM and NASADEM also performed well where available, whereas NASADEM, as a successor of SRTM, showed only slight improvement in comparison to SRTM. MERIT and TanDEM-X also performed well despite their lower spatial resolution.

  • Publication . Master thesis . 2020
    Open Access Estonian
    Authors: 
    Oidekivi, Maarika;
    Publisher: Tartu Ülikool
    Country: Estonia

    Robotite ning inimeste ruumi jagamiseks ning koostöö jaoks on vajalik omavaheline suhtlus. Roboti ja inimese vahelises suhtluses on tähtis nii masinapoolne inimese mõistmine kui ka see, et inimene mõistaks roboti poolt edastatut. Selleks on vaja, et robot suudaks end inimesele arusaadaval viisil selgeks teha. Käesoleva magistritöö eesmärgiks oli uurida erinevaid võimalusi roboti kavatsuse väljendamiseks ning selle raames koostati kirjanduse kokkuvõte erinevatest juba välja pakutud kavatsuse väljendamise variantidest, viidi läbi küsitlus Eesti inimeste seas, et analüüsida nende arusaamist masina kavatsusest ning loodi masina mudel, mida visualiseeriti simulatsioonikeskkonnas. Küsimustikust selgus, et Eesti inimesed ei pruugi masina poolt edastatavaid emotsioone mõista, kui kasutatakse ainult roboti silmi. Samuti selgus, et ilma eelnevate teadmisteta ei olnud inimesed võimelised sõidukite kavatsusi ära tundma, kui kasutuses olid LED-ribad või -ekraanid, projektsioonide puhul said inimesed sõiduki kavatsusest aru. In english: For humans and robots to share space and cooperate, it is necessary to communicate with each other. In the communication between a human and a robot it is important for the machine to understand the human and also for the human to understand the information transmitted by the robot. This requires, that the robot would be able to make itself clear to humans in an understandable way. The aim of this thesis was to evaluate different approaches to communicate the intent of a machine. During the master’s thesis, an overview of various options already proposed to express intent was given, a suvery was conducted among Estonian people to analyze their understanding of machine intent and a model of an autonomous car capable of communicating intent was proposed and visualised in a simulator. The survey revealed that Estonians may not understand the emotions of a machine if only robot’s eyes are used. It was also found that without prior knowledge, people were not able to understand vehicle intent when LED strips and displays were used, people recognized the intent when projections were used.

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The following results are related to Rural Digital Europe. Are you interested to view more results? Visit OpenAIRE - Explore.
32 Research products, page 1 of 4
  • Open Access English
    Authors: 
    Mass, Jakob;
    Country: Estonia

    Värkvõrk, ehk Asjade Internet (Internet of Things, lüh IoT) edendab lahendusi nagu nn tark linn, kus meid igapäevaselt ümbritsevad objektid on ühendatud infosüsteemidega ja ka üksteisega. Selliseks näiteks võib olla teekatete seisukorra monitoorimissüsteem. Võrku ühendatud sõidukitelt (nt bussidelt) kogutakse videomaterjali, mida seejärel töödeldakse, et tuvastada löökauke või lume kogunemist. Tavaliselt hõlmab selline lahendus keeruka tsentraalse süsteemi ehitamist. Otsuste langetamiseks (nt milliseid sõidukeid parasjagu protsessi kaasata) vajab keskne süsteem pidevat ühendust kõigi IoT seadmetega. Seadmete hulga kasvades võib keskne lahendus aga muutuda pudelikaelaks. Selliste protsesside disaini, haldust, automatiseerimist ja seiret hõlbustavad märkimisväärselt äriprotsesside halduse (Business Process Management, lüh BPM) valdkonna standardid ja tööriistad. Paraku ei ole BPM tehnoloogiad koheselt kasutatavad uute paradigmadega nagu Udu- ja Servaarvutus, mis tuleviku värkvõrgu jaoks vajalikud on. Nende puhul liigub suur osa otsustustest ja arvutustest üksikutest andmekeskustest servavõrgu seadmetele, mis asuvad lõppkasutajatele ja IoT seadmetele lähemal. Videotöötlust võiks teostada mini-andmekeskustes, mis on paigaldatud üle linna, näiteks bussipeatustesse. Arvestades IoT seadmete üha suurenevat hulka, vähendab selline koormuse jaotamine vähendab riski, et tsentraalne andmekeskust ülekoormamist. Doktoritöö uurib, kuidas mobiilsusega seonduvaid IoT protsesse taoliselt ümber korraldada, kohanedes pidevalt muutlikule, liikuvate seadmetega täidetud servavõrgule. Nimelt on ühendused katkendlikud, mistõttu otsuste langetus ja planeerimine peavad arvestama muuhulgas mobiilseadmete liikumistrajektoore. Töö raames valminud prototüüpe testiti Android seadmetel ja simulatsioonides. Lisaks valmis tööriistakomplekt STEP-ONE, mis võimaldab teadlastel hõlpsalt simuleerida ja analüüsida taolisi probleeme erinevais realistlikes stsenaariumites nagu seda on tark linn. The Internet of Things (IoT) promotes solutions such as a smart city, where everyday objects connect with info systems and each other. One example is a road condition monitoring system, where connected vehicles, such as buses, capture video, which is then processed to detect potholes and snow build-up. Building such a solution typically involves establishing a complex centralised system. The centralised approach may become a bottleneck as the number of IoT devices keeps growing. It relies on constant connectivity to all involved devices to make decisions, such as which vehicles to involve in the process. Designing, automating, managing, and monitoring such processes can greatly be supported using the standards and software systems provided by the field of Business Process Management (BPM). However, BPM techniques are not directly applicable to new computing paradigms, such as Fog Computing and Edge Computing, on which the future of IoT relies. Here, a lot of decision-making and processing is moved from central data-centers to devices in the network edge, near the end-users and IoT sensors. For example, video could be processed in mini-datacenters deployed throughout the city, e.g., at bus stops. This load distribution reduces the risk of the ever-growing number of IoT devices overloading the data center. This thesis studies how to reorganise the process execution in this decentralised fashion, where processes must dynamically adapt to the volatile edge environment filled with moving devices. Namely, connectivity is intermittent, so decision-making and planning need to involve factors such as the movement trajectories of mobile devices. We examined this issue in simulations and with a prototype for Android smartphones. We also showcase the STEP-ONE toolset, allowing researchers to conveniently simulate and analyse these issues in different realistic scenarios, such as those in a smart city. https://www.ester.ee/record=b5525514

  • Open Access English
    Authors: 
    Montibeller, Bruno;
    Country: Estonia

    Forests are strongly impacted by human activities. While the deforestation is very likely the most common examples of human impact on forested areas, the remaining standing forests are susceptible to other types of direct or indirect forest degradation by humans. The direct human-induced impacts can be exemplified by forest fragmentation or selective logging while the indirect human-induced impacts can be related to the changes in the ecosystem services (e.g., carbon and water cycling) induced by anthropogenic climate change. The aim of this thesis was to evaluate two processes related to forest degradation: (i) fragmentation of tropical forest cover in the Brazilian Amazon and (ii) changes in forest evapotranspiration over/across the Baltic countries and the carbon cycle in undisturbed forest areas across Europe. Satellite derived data and spatial analyses were used to assess the impacts of forest degradation in these three different case studies. The results of this thesis showed that although the anti-deforestation initiatives have played an important role in reducing deforestation in the Brazilian Amazon region, the forest fragmentation has increased mainly because of the decrease in the size of forest loss patches and the spatial shift into areas previously isolated areas. Hence, more forest areas are potentially being degraded because of the edge effects (e.g., tree mortality) caused by the fragmentation. For the Baltic region, the results indicated an intensification of the evapotranspiration rates over undisturbed forest areas. The intensification occurred mainly during spring and early autumn months because of the longer growing season induced by the increasing temperatures during these periods. Changes in the climate patterns were also the potential cause for changes in the carbon assimilation rates over the European forests. Approximately 25% of the undisturbed European forests showed reduced total carbon assimilation. That shows the vulnerability and incapacity of certain forest areas to act as carbon sink. Metsaökosüsteemid võivad siduda kuni 12% inimtekkelisest süsihappegaasist ning tagastada atmosfääri kuni 40% kohalikest sademetest. Seetõttu on metsaökosüsteemidel oluline roll süsihappegaasi emissioonide vähendamisel ja veeringe reguleerimisel. Samal ajal väheneb metsade pindala ning metsad degradeeruvad läbi killustumise ning nende süsiniku- ja veeringe reguleerimise võime võib väheneda kliimamuutuste tõttu. Käesoleva doktoritöö eesmärgiks oli hinnata kahte metsade degradeerumisega seotud protsessi: (1) troopilise vihmametsa killustumist Brasiilia Amasoonias ja (2) muutuseid evapotranspiratsioonis ja süsinikuringes Baltikumi ja Eurooma muutumatuna püsinud metsamassiivides. Käesoleva doktoritöö tulemused näitasid, et kuigi Brasiilias on metsatustumise vastased poliitikad vähendanud metsade raadamist, siis samal ajal on suurenenud metsade killustumine, sest raiutakse väiksemate eraldiste kaupa ja liikudes endiselt varem raadamata aladele. Killustunud metsas on rohkem metsaserva, kust on süsinikukaod suuremad nii leostumise kui ka gaasilise emissioonina. Baltikumis leiti, et pikem taimekasvuperiood on suurendanud evapotranspiratsiooni kevadel ja sügisel, kuid samal ajal on suvel evapotranspiratsioon mõnedes piirkondades vähenenud. Kuigi evapotranspiratsiooni suurenemisel ei ole metsade ökosüsteemile otseselt negatiivset mõju, siis võib sellel olla ebasoovitav mõju regiooni veeringele, sest suurenenud evapotranspiratsioon suurendab tõenäosust, et suveperioodil on mullas vähem vett, mis omakorda suurendab põuaohtu. Lisaks selgus, et neljandikus Euroopa muutumatuna püsinud metsamassiivides on süsiniku sidumine vähenenud. Vähenenud süsiniku sidumisega metsamassiivid paiknesid üle kogu Euroopa ning hõlmasid erinevaid metsatüüpe. Kliimamuutuste mõjul võib metsade süsiniku sidumine väheneda veelgi rohkem, mis seab kahtluse alla varasemalt eeldatud metsade võimekuse leevendada kliimamuutuste mõjusid. Väitekirja elektrooniline versioon ei sisalda publikatsioone https://www.ester.ee/record=b5519495

  • Open Access English
    Authors: 
    Vahter, Tanel;
    Country: Estonia

    This doctoral thesis provides a deeper understanding of the ecology of soil fungi that form mycorrhizas in arable landscapes. These fungi provide plants with much needed soil nutrients and are therefore a vital part of sustainable food production. One of the central aims was to understand how the common agricultural practices used in the fields affect these key fungi. In our studies we found that much like in the rest of Europe, there are large differences in the diversity of mycorrhizal fungi in arable field soils. Differences in mycorrhizal fungal richness between the most and least diverse fields were sixfold. The major factors decreasing mycorrhizal fungal diversity were the use of synthetic fertilizers and pesticides but also biodiversity impoverished agricultural landscapes. In addition, we learned that temporary grasslands within the crop rotations have important implications for sustaining soil fungal biodiversity. Furthermore, we found that the crop varieties sown can have an impact on mycorrhizal fungi, with some older varieties faring better in organically managed soils than newer breeds. Although the plants’ affinity to mycorrhizal fungi was not clearly dependant on the era a variety was bred, it does show that we should bear mycorrhizal associations in mind when breeding crops of the future. We also experimented with creating diverse vegetation assemblages in biodiversity impoverished landscapes, using depleted oil-shale quarries as a model system. We used native plants and sowed them onto the restoration sites together with the mycorrhizal fungi they naturally grow with. Using this methodology, we were able to bring dosens of plant species into a former biodiversity desert, highlighting the possibilities of restoring biodiversity hot-spots also in other areas. To conclude, we emphasize that safeguarding the biodiversity of vital mycorrhizal fungi is possible even with the measures available to farmers today. More organic fertilizers with diverse crop rotations for disease and weed control, accompanied by the biodiversity support of diverse landscapes is something that would pave the way for sustainable food production. Doktoritöö käigus uuriti taimede ja seente vahelist vastastikku kasulikku kooselu, mükoriisat, moodustavate mullaseente ökoloogiat põllumajandusmaastikes. Kuna nende seente abil saavad taimed mullast vajaminevaid toitaineid, on nad oluline osa mulla elustikust ning panustavad ka põllumajanduse jätkusuutlikkusse. Töö üks põhieesmärke oli uurida, kuidas levinud põlluharimise praktikad mükoriisaseeni mõjutavad ning millised praktikad võiksid nende elurikkust suurendada. Uuringutes leidsime, et sarnaselt Lääne-Euroopaga on ka Eestis olenevalt põlluharimise viisidest mükoriisaseente elurikkuses suured erinevused – mitmekesisemate ja vaesemate põldude mükoriisaseente liigirikkuse vahe oli koguni kuuekordne. Olulisteks negatiivseteks teguriteks olid sünteetiliste väetiste ja pestitsiidide kasutamine, kuid positiivselt mõjusid orgaaniliste väetiste kasutamine ja maastikuelementide rohkus. Lisaks saime teada, et lühiajaliste rohumaade lisamine külvikorda soodustab mullaseeni ning külvikorra planeerimisel tasuks mõelda kasvatatavate sortide valiku peale. Näiteks selgus, et mõned ajaloolised nisusordid kasvavad paremini koos mahetootmise põllu mullast pärit seentega, samas kui mõni kaasaegne sort jällegi intensiivtootmise mulla seentega. Selle teadmise baasilt oleks võimalik tulevikus aretada näiteks mükoriisasõbralikke sorte nii mahe- kui tavaviljelusse. Lisaks eksperimenteerisime ka liigirikaste taimekoosluste taastamisega, luues liigivaestesse põlevkivikarjääridesse mükoriisaseente abiga kõigest mõne aastaga rohelised niidud. Sama metoodikat kasutades võiks tekitada elurikkuse tugipunkte ka intensiivselt majandatud põllumajandusmaastikesse, kus taimede, putukate ja mükoriisaseente elustik põllumajandustootjale kasu saaks tuua. Seega, kasutades rohkem orgaanilisi väetisi ja tõrjudes haiguseid ning kahjureid mitmekesise külvikorraga saab luua mükoriisaseeni soodustavad tingimused. Lisades maastikesse veel uusi ja hoides olemasolevaid elurikkuse tugipunkte, võiksime olla eeskujuks oma kodukandi kõrge elurikkuse ja sellega arvestava toidutootmisega. Väitekirja elektrooniline versioon ei sisalda publikatsioone https://www.ester.ee/record=b5449439

  • Open Access English
    Authors: 
    Draheim, Dirk; Krimmer, Robert; Tammet, Tanel;
    Publisher: Springer, Berlin, Heidelberg
    Country: Estonia

    The \digital transformation" is perceived as the key enabler for increasing wealth and well-being by politics, media and the citizens alike. In the same vein, digital government steadily receives more and more attention. Digital government gives rise to complex, large-scale state-level system landscapes consisting of many players and technological systems { and we call such system landscapes digital government ecosystems. In this paper, we systematically approach the state-level architecture of digital government ecosystems.We will discover the primacy of the state's institutional design in the architecture of digital government ecosystems, where Williamson's institutional analysis framework supports our considerations as theoretical background. Based on that insight, we will establish the notion of data governance architecture, which links data assets with accountable organizations. Our investigation results into a digital government architecture framework that can help in large-scale digital government design e_orts through (i) separation of concerns in terms of appropriate categories, and (ii) a better assessment of the feasibility of envisioned digital transformations. With its focus on data, the proposed framework perfectly _ts the current discussion on moving from ICT-driven to data-centric digital government.

  • Open Access
    Authors: 
    Alexander Kmoch; Arno Kanal; Alar Astover; Ain Kull; Holger Virro; Aveliina Helm; Meelis Pärtel; Ivika Ostonen; Evelyn Uuemaa;
    Publisher: Copernicus GmbH
    Country: Estonia
    Project: EC | GLOMODAT (795625)

    To understand, model, and predict landscape evolution, ecosystem services, and hydrological processes, the availability of detailed observation-based soil data is extremely valuable. For the EstSoil-EH dataset, we synthesized more than 20 eco-hydrological variables on soil, topography, and land use for Estonia (https://doi.org/10.5281/zenodo.3473289, Kmoch et al., 2019a) as numerical and categorical values from the original Soil Map of Estonia, the Estonian 5 m lidar DEM, Estonian Topographic Database, and EU-SoilHydroGrids layers. The Soil Map of Estonia maps more than 750 000 soil units throughout Estonia at a scale of 1:10 000 and forms the basis for EstSoil-EH. It is the most detailed and information-rich dataset for soils in Estonia, with 75 % of mapped units smaller than 4.0 ha, based on Soviet-era field mapping. For each soil unit, it describes the soil type (i.e. soil reference group), soil texture, and layer information with a composite text code, which comprises not only the actual texture class, but also classifiers for rock content, peat soils, distinct compositional layers, and their depths. To use these as eco-hydrological process properties in modelling applications we translated the text codes into numbers. The derived parameters include soil layering, soil texture (clay, silt, and sand contents), coarse fragments, and rock content of the soil layers within the soil profiles. In addition, we aggregated and predicted physical variables related to water and carbon cycles (bulk density, hydraulic conductivity, organic carbon content, available water capacity). The methodology and dataset developed will be an important resource for the Baltic region, but possibly also for all other regions where detailed field-based soil mapping data are available. Countries like Lithuania and Latvia have similar historical soil records from the Soviet era that could be turned into value-added datasets such as the one we developed for Estonia.

  • Open Access English
    Authors: 
    Hartmann, Dennis;
    Publisher: Tartu Ülikool
    Country: Estonia
  • Open Access English
    Authors: 
    Kustavus, Allan;
    Publisher: Tartu Ülikool
    Country: Estonia

    Autonomous robots are utilized in a wide range of domains, combining a large number of resources like sensors, actuators and algorithms to form a self-acting robotic system. Tools, such as ROS and TeMoto, have been developed to allow for handling and managing of resources composing such systems. While TeMoto is meant to handle dynamic and changing situations the current implementation of its Resource Registrar, a core TeMoto component tasked with allocating, deallocating and tracking of resources, is tightly coupled to ROS, making it difficult to modify and improve. As a result of this thesis, the Resource Registrar (RR) of TeMoto was completely redesigned to be extendable to other robotic middleware, such as ROS2, and to improve TeMoto’s robustness with features, e.g., full recovery of the RR, that were unattainable with the previous design.

  • Open Access English
    Authors: 
    Milyakina, Alexandra;
    Country: Estonia

    Despite the common concern, young people today are engaging with literature more than ever, albeit in the ways that are not always recognized. Literary education in the digital age implies navigating a heterogeneous world of metatexts in different media and integrating them into a coherent whole. Rather than reading the original versions of literary texts, people often gain information from elsewhere, i.e. by watching film adaptations, scrolling through memes, playing video games, or reading comments on Youtube. In contrast to printed books that are mostly verbal, linear and created by a single author, digital texts are becoming increasingly multimodal, non-linear and collaborative. Apart from a qualitative and quantitative change in the nature of texts, digitalization entails a shift in social relations: producers and consumers merge into prosumers, while teachers turn into knowledge facilitators rather than all-knowing others. While the current situation can be certainly considered as a moment of explosion, this work mostly focuses on its opposite – the stage of gradual development. The thesis explores the transformation of literary education from different angles. At first, it discusses the applicability of different forms of texts and practices to teaching literature, such as digital and film adaptations, games, and project development workshops. Secondly, it synthesizes the ideas of the Tartu-Moscow Semiotic School and the multimodal approach, in order to analyze literary education in the context of cultural autocommunication as well as through the prism of social relations. Finally, it suggests pedagogical and technological solutions for bridging the gap between formal literary education and vernacular digital practices. The thesis aims to answer research questions by means of experimentation rather than by a theoretical argument: the findings are based on the empirical material gathered while working on the Education on Screen project. Vaatamata levinud arvamusele on noorte inimeste kirjanduselu aktiivsem kui kunagi varem. Kirjandusega suheldakse lihtsalt viisidel, mis ei pruugi alati laiemat tunnustamist leida. Digiajastul hõlmab kirjandusharidus erinevates meediumites loodud metatekstide mitmekesises võrgustikus navigeerimist ja nende pinnalt terviku integreerimist. Algtekstide esialgsel kujul lugemise asemel hangitakse selle kohta teadmisi nt ekraniseeringute, meemide, videomängude või isegi YouTube’i kommentaaride vahendusel. Verbaalsele, lineaarsele ja üksikautorluses trükiraamatule vastukaaluks on digitaalsed tekstid multimodaalsed, mittelineaarsed ja koosloomelised. Tekstide kvantitatiivsete ja kvalitatiivsete omaduste muutuste kõrval on digitaliseerumine kaasa toonud nihked ka kirjandusharidust puudutavates sotsiaalsetes suhetes - loojad ja vastuvõtjad segunevad, kõike teadvatest õpetajatest saavad juhendajad iseseisvas teadmiste omandamise protsessis. Sellist olukorda võib vaadelda kultuurilise plahvatushetkena, kuid käesolev töö keskendub vastasküljele -- pidevale muutusele. Väitekiri käsitleb kirjandushariduse muutumist erinevate nurkade alt. Esiteks vaadeldakse eelnimetatud metatekstide rakendatavust kirjanduse õpetamisel. Teiseks sünteesitakse Tartu-Moskva semiootikakoolkonna ning multimodaalsuse uuringuid analüüsimaks kirjandusharidust nii kultuurilise autokommunikatsiooni kontekstis kui läbi sotsiaalsete suhete prisma. Viimaseks pakutakse välja pedagoogilisi ja tehnoloogilisi lahendusi, et ületada formaalse kirjandushariduse ja igapäevaste digitaalsete praktikate vahelist lõhet. Väitekirjas lähenetakse uurimisküsimustele eksperimentaalselt ning töö aluseks olev empiiriline materjal pärineb autori osalusel valminud digitaalselt õppeplatvormilt Haridus Ekraanil ja selle kasutamiskogemustest. Väitekirja elektrooniline versioon ei sisalda publikatsioone https://www.ester.ee/record=b5383228

  • Open Access
    Authors: 
    Evelyn Uuemaa; Sander Ahi; Bruno Montibeller; Merle Muru; Alexander Kmoch;
    Publisher: MDPI AG
    Country: Estonia
    Project: EC | GLOMODAT (795625)

    Freely available global digital elevation models (DEMs) are important inputs for many research fields and applications. During the last decade, several global DEMs have been released based on satellite data. ASTER and SRTM are the most widely used DEMs, but the more recently released, AW3D30, TanDEM-X and MERIT, are being increasingly used. Many researchers have studied the quality of these DEM products in recent years. However, there has been no comprehensive and systematic evaluation of their quality over areas with variable topography and land cover conditions. To provide this comparison, we examined the accuracy of six freely available global DEMs (ASTER, AW3D30, MERIT, TanDEM-X, SRTM, and NASADEM) in four geographic regions with different topographic and land use conditions. We used local high-precision elevation models (Light Detection and Ranging (LiDAR), Pleiades-1A) as reference models and all global models were resampled to reference model resolution (1m). In total, 608 million 1x1 m pixels were analyzed. To estimate the accuracy, we generated error rasters by subtracting each reference model from the corresponding global DEM and calculated descriptive statistics for this difference (e.g., median, mean, root-mean-square error (RMSE)). We also assessed the vertical accuracy as a function of the slope, slope aspect, and land cover. We found that slope had the strongest effect on DEM accuracy, with no relationship for slope aspect. The AW3D30 was the most robust and had the most stable performance in most of the tests and is therefore the best choice for an analysis of multiple geographic regions. SRTM and NASADEM also performed well where available, whereas NASADEM, as a successor of SRTM, showed only slight improvement in comparison to SRTM. MERIT and TanDEM-X also performed well despite their lower spatial resolution.

  • Publication . Master thesis . 2020
    Open Access Estonian
    Authors: 
    Oidekivi, Maarika;
    Publisher: Tartu Ülikool
    Country: Estonia

    Robotite ning inimeste ruumi jagamiseks ning koostöö jaoks on vajalik omavaheline suhtlus. Roboti ja inimese vahelises suhtluses on tähtis nii masinapoolne inimese mõistmine kui ka see, et inimene mõistaks roboti poolt edastatut. Selleks on vaja, et robot suudaks end inimesele arusaadaval viisil selgeks teha. Käesoleva magistritöö eesmärgiks oli uurida erinevaid võimalusi roboti kavatsuse väljendamiseks ning selle raames koostati kirjanduse kokkuvõte erinevatest juba välja pakutud kavatsuse väljendamise variantidest, viidi läbi küsitlus Eesti inimeste seas, et analüüsida nende arusaamist masina kavatsusest ning loodi masina mudel, mida visualiseeriti simulatsioonikeskkonnas. Küsimustikust selgus, et Eesti inimesed ei pruugi masina poolt edastatavaid emotsioone mõista, kui kasutatakse ainult roboti silmi. Samuti selgus, et ilma eelnevate teadmisteta ei olnud inimesed võimelised sõidukite kavatsusi ära tundma, kui kasutuses olid LED-ribad või -ekraanid, projektsioonide puhul said inimesed sõiduki kavatsusest aru. In english: For humans and robots to share space and cooperate, it is necessary to communicate with each other. In the communication between a human and a robot it is important for the machine to understand the human and also for the human to understand the information transmitted by the robot. This requires, that the robot would be able to make itself clear to humans in an understandable way. The aim of this thesis was to evaluate different approaches to communicate the intent of a machine. During the master’s thesis, an overview of various options already proposed to express intent was given, a suvery was conducted among Estonian people to analyze their understanding of machine intent and a model of an autonomous car capable of communicating intent was proposed and visualised in a simulator. The survey revealed that Estonians may not understand the emotions of a machine if only robot’s eyes are used. It was also found that without prior knowledge, people were not able to understand vehicle intent when LED strips and displays were used, people recognized the intent when projections were used.