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The RAdiative transfer Model Intercomparison (RAMI) activity focuses on the benchmarking of canopy radiative transfer (RT) models. For the current fourth phase of RAMI, six highly realistic virtual plant environments were constructed on the basis of intensive field data collected from (both deciduous and coniferous) forest stands as well as test sites in Europe and South Africa. Twelve RT modelling groups provided simulations of canopy scale (directional and hemispherically integrated) radiative quantities, as well as a series of binary hemispherical photographs acquired from different locations within the virtual canopies. The simulation results showed much greater variance than those recently analysed for the abstract canopy scenarios of RAMI-IV. Canopy complexity is among the most likely drivers behind operator induced errors that gave rise to the discrepancies. Conformity testing was introduced to separate the simulation results into acceptable and non-acceptable contributions. More specifically, a sharedrisk approach is used to evaluate the compliance of RT model simulations on the basis of reference data generated with the weighted ensemble averaging technique from ISO-13528. However, using concepts from legal metrology, the uncertainty of this reference solution will be shown to prevent a confident assessment of model performance with respect to the selected tolerance intervals. As an alternative, guarded risk decision rules will be presented to account explicitly for the uncertainty associated with the reference and candidate methods. Both guarded acceptance and guarded rejection approaches are used to make confident statements about the acceptance and/or rejection of RT model simulations with respect to the predefined tolerance intervals.

Eesti kõrgkoolide 2012. aasta vilistlaste uuringu eesmärk oli ülevaate saamine vilistlaste lõpetamisjärgsest tegevusest, toimetulekust tööturul ja hinnangutest kõrgkooli õppetöö kvaliteedile ning omandatud pädevustele. Kõiki kõrgkoole hõlmav uuring viidi esmakordselt läbi 2011. aastal, uuriti 2009. aastal lõpetanuid. Käesolev on järg eelnevale, hindamaks vahepealsel ajal (2009-2012) toimunud muutusi.

International audience; Forest management is considered to be one of the key instruments available to mitigate climate change as it can lead to increased sequestration of atmospheric carbon dioxide. However, the changes in canopy albedo may neutralise or offset the climate benefits of carbon sequestration. Although there is an emerging body of literature linking canopy albedo to management, understanding is still fragmented. We make use of a generally applicable approach: we combine a stand-level forest gap model with a canopy radiation transfer model and satellite-derived model parameters to quantify the effects of forest management on canopy albedo for different forest species and management strategies. We find that the most intensive management measures lead to largest albedo change. The choice of species in combination with thinning dominates the variation in canopy albedo. In addition, the canopy albedo of forest stands changes with the latitude, i.e. forest stands with similar structure have different albedo depending on the latitude. The structural changes associated with forest management can be described by change in LAI in combination with crown volume. However, not only the removal of trees but also the type of understorey affects the canopy albedo. The lower the canopy cover, the larger the background albedo contributes to the canopy albedo. In summary, forest albedo is strongly altered by humans.

Väitekirja elektrooniline versioon ei sisalda publikatsioone., Finantskriiside nakkuslikkuseks peetakse olukorda, kus kriisiperioodidel toimuvad olulised struktuursed muutused kriisi- ja sihtriigi vahelistes šokkide ülekandemehhanismides. Sisuliselt tähendab see, et kriisi ülekandumist ei saa põhjendada riikidevaheliste seoste (kaubanduslike, finants- või poliitiliste) ega sihtriigi makromajanduslike fundamentaalnäitajatega. Doktoritöö eesmärgiks on tõestada või ümber lükata finantskriiside nakkusliku levimise toimumine olulisemate kriisiepisoodide ajal ning leida meta-analüüsi metoodika abil nakkuslikkuse taseme peamised mõjutegurid. Töös seatakse uurimisprobleemi mitmetahulisuse tõttu kahtluse alla suure osa varasemate uuringute rõhuasetus finantsnakkuse statistilise olulisuse testimisele ja soovitatakse keskenduda konkreetse kvantitatiivse mõõdiku leidmisele, mis oleks üle uuringute ühtselt interpreteeritav ja agregeeritav ning ühismõõdustaks sellega erinevate uuringute tulemused võimaldades oluliselt paremini kaasata uuringuid tuleviku meta-analüüsidesse. Üks selline mõõdik on dissertatsioonis ka välja pakutud ja empiirilises analüüsis kasutatud. Uurimistulemused näitavad, et kriiside ülekandumine on kohati tõepoolest olnud nakkuslik, kuid mitte kuigi tugeval määral. See tähendab, et kriiside riigist riiki levimist ei saa selgitada ainult tugevate riikidevaheliste ühenduskanalite ega halbade makromajanduslike fundamentaalnäitajatega, vaid tuleb otsida põhjuseid investorite käitumuslikest aspektidest. Äärmiselt oluliseks muutuvad kriisi tingimustes herding-kontseptsioonist ja muudest kollektiivses mõttes irratsionaalse käitumise aspektidest tulenevad iseenese täitumisele viivad ootused. Niisugustes tingimustes tuleb traditsioonilistesse investeerimisportfelli riskantsuse vähendamisele suunatud teooriatesse suhtuda ülima ettevaatlikkusega, kuna nad ülehindavad oluliselt investeerimisportfelli rahvusvahelise diversifitseerimisega saavutatavat riskiastme vähenemist investorite ratsionaalse käitumise eelduse tõttu riski tingimustes. Sobiva finantsarhitektuuri otsimise kontekstis tähendab finantsnakkuslikkuse eksisteerimine vajadust arvestada möödapääsmatute kriisiepisoodidega ning seega oleks soovitav koguda majanduskasvu perioodidel varusid reservi, et nende abil kriiside ülekandumise mõjusid pehmendada., The aim of the study is to find out whether the propagation of financial crises in numerous past crisis episodes has been amplified by financial contagion or is based solely on stable fundamental linkages between countries. It is shown that because of the multidimensionality of the research problem literature reviews and even more so individual studies do not provide sufficient answers to the financial contagion puzzle. Therefore, one contribution of the thesis is to suggest future research be conducted on the field of financial contagion with more emphasis on finding singular numerical values that are interpretable and comparable, and therefore, summarisable across all relevant studies, rather than trying to come out with some statistical significance measure of some contagion parameter. One potential measure of this kind is proposed in the theoretical part of the thesis and is used in the following empirical analysis. The empirical findings indicate that some contagion has been present in recent crisis episodes but these effects have been rather moderate. The contagiousness of transmission of crises varies depending on observed crisis and financial market but not significantly on development level of destination countries. An important policy implication from the results of the thesis is that potential benefits from international portfolio diversification are significantly lower than one might expect. If one country falls, others are not safe either, as herding behaviour or some other form of collectively irrational behaviour among financial agents can easily occur. At the government level, some guidelines for appropriate financial architecture that take into account the presence of financial contagion in international markets can be drawn. As closeting themselves behind iron curtains seems neither realistic nor reasonable, nothing more than countries putting aside financial reserves during good times for use when financial contagion hits can really be suggested.