Prediction of dynamic pairwise wake vortex separations for approach and landing

Design and performance of the Wake Vortex Prediction and Monitoring System WSVBS are described. The WSVBS has been developed to tactically increase airport capacity for approach and landing on single runways as well as closely-spaced parallel runways. It is thought to dynamically adjust aircraft separations dependent on weather conditions and the resulting wake vortex behavior without compro-mis>ing safety. Dedicated meteorological instrumentation and short-term numerical terminal weather prediction provide the input to the prediction of wake-vortex behavior and respective safety areas. LIDAR monitors the correctness of WSVBS predictions in the most critical gates at low altitude. The WSVBS is integrated in the arrival manager AMAN of DLR. Performance tests of the WSVBS have been accomplished at Frankfurt airport in winter 2006/07 and at Munich Airport in summer 2010. Aircraft separations for landings on single runways have been compared employing the concepts of either heavy-medium weight class combinations or dynamic pairwise separations where individual aircraft type pairings are considered. For the very conservative baseline setup of the WSVBS the potential capacity gains of dynamic pairwise operations for single runways appear to be very small. On the other hand, the consideration of individual aircraft types and their respective wake characteristics may almost double the fraction of time when radar separation could be applied

Mükoriisse sümbioosi levik ja roll taimekooslustes

Väitekirja elektrooniline versioon ei sisalda publikatsiooneMükoriisne sümbioos soontaimede ja mullaseente vahel on maismaaökosüsteemides laialt levinud ja mängib olulist rolli nende toimimises. Antud doktoritöö avardab teadmisi mükoriissuse levikust taimkattes, seda mõjutavatest keskkonnateguritest ja sellest, kuidas mükoriissus mõjutab taimede kooseksisteerimist ja mitmekesisust. Eesti taimekoosluste analüüsimisel selgus, et parasvöötme metsad on mükoriissemad, kuid suhteliselt vähem arbuskulaar-mükoriissemad võrreldes rohumaadega ning see on põhjustatud erinevustest mullaviljakuses, -happesuses ja -niiskuses. Kontinentaalsel skaalal nähtus, et erinevate mükoriissete tunnustega taimedel on erinev levikumuster piki laiuskraadi: arbuskulaar-mükoriissed taimed domineerivad kogu Euroopas, kuid nende osakaal kahaneb põhjapoolsetel aladel. Seevastu ekto- ja erikoidset mükoriisat moodustavate taimede osakaal on madal laiuskraadist sõltumata. Euroopa põhjapoolsemaid alasid iseloomustab mükoriisse sümbioosi osatähtsuse vähenemine. Lisaks ilmnes, et kontinentaalsel skaalal mängivad mükoriisse sümbioosi levikul olulist rolli nii mulla- kui ka kliimatingimused. Ühtlasi osutasid tulemused ka mükoriissuse tähtsusele taimekoosluste mitmekesisuse kujunemisel: arbuskulaar-mükoriissus soosis taimede liigirikkust uuritud metsades. Üheks võimalikuks viisiks, kuidas mükoriisa moodustamine taimede kooseksisteerimist mõjutada võib, on taimede ressursi- ja elupaiganõudluste ehk niššide muutmine. Oma tulemustega näitasime esimest korda, et erinevate mükoriissete tunnustega taimedel on tõepoolest erinevad nišid, võides seega muuta taimedevahelisi suhteid. Oluliseks probleemiks looduslikes kooslustes on süvenev inimtegevus. Hollandi taimkatte põhjal tehtud uuringus selgus, et inimtegevus muudab taimekoosluste mükoriissust, kuid selle mõju sõltub inimtegevuse tüübist ja koosluse valdavast mükoriisatüübist. Üldiselt selgus siiski, et inimtegevus mõjutab mükoriissust enim metsades ja nõmmekooslustes, võides muuta ka aineringete toimimist.Mycorrhizal symbiosis between vascular plants and soil fungi is considered ubiquitous in terrestrial ecosystems and plays a key role in ecosystem processes. This doctoral thesis advances our understanding about the distribution of mycorrhizal symbiosis in vegetation at larger scales, its drivers and how it relates to plant coexistence and diversity. At regional scale, we show quantitatively that the forests in Estonia are more mycorrhizal but less arbuscular mycorrhizal than grasslands and vice versa. These distribution patterns were driven by edaphic factors, such as soil fertility, pH and moisture. At the continental scale, we revealed the latitudinal distribution patterns of plants with different mycorrhizal traits: arbuscular mycorrhizal plants prevailed across Europe, although their share decreased in the north, while minor but opposite trends were observed for ecto- and ericoid mycorrhizal plants. Northern areas in Europe were characterized by increased share of non-mycorrhizal and facultatively mycorrhizal plants. The mycorrhizal distribution at the continental scale was driven both by soil and climatic factors. Our results also suggest that arbuscular mycorrhization in Estonian forests is associated with higher plant richness. Mycorrhizal symbiosis could potentially affect plant diversity by reducing resource competition between plant species, i.e., by promoting plant niche partitioning. For the first time, we show that plants with different mycorrhizal characteristics indeed show evidence of niche differentiation. Also, mycorrhizal associations could be influenced by increasing human pressure on ecosystems. The analysis of the Dutch vegetation showed that mycorrhization of plant communities is affected by anthropogenic influence, but the effect depends on the type of human impact and the dominant mycorrhizal type. However, the mycorrhization of forests and heathlands were most affected, potentially also having subsequent effects on nutrient cycling.https://www.ester.ee/record=b552954

An Akka-based middleware for Laboratory Information Systems

Andmevahetus meditsiiniliste analüsaatoritega on oluline osa igast laboriinfosüsteemist. Analüsaatorid ja infosüsteem vahetavad andmeid nagu näiteks analüüside tulemused, tellimused ja patsiendi informatsioon. Suure koormusega laborites teostatakse analüüse ööpäevaringselt, mistõttutu võib käsitsi andmete sisestamine pudelikaelaks labori töös. Et suurendada laboripersonali efektiivsust ning inimeksimusi, tuleb andmevahetus automatiseerida. Tehniliste piirangute ja andmevahetusprotokollide rohkuse tõttu kasutatakse sageli vahevara tarkvara, mis vahendab andmevahetust laboriinfosüsteemi ja analüsaatorite vahel. Katkestus andmevahetuses võib põhjustada rahalist kahju või isegi ohtu elule. Seega tuleb vahevara arendamisel arvesse võtta teatud nõudeid, et see oleks usaldusväärne ja hallatav. See bakalaureusetöö annab ülevaate laboriinfosüsteemi ja analüsaatorite liidestamisest ning selle käigus valmib Akka teegil baseeruv vahevara prototüüp. Prototüübi ühe osana implementeeritakse ka liidestus ühe hüpoteetilise analüsaatori ja laboriinfosüsteemi vahel. Prototüübi näitel analüüsitakse, kuivõrd on Akka teek sobilik implementeerimaks vahevara, mis rahuldab nõudeid nagu veataluvus, paralleelsus ning koodi taaskasutatavus. Tulemusena valmivat prototüüpi on võimalik kasutada raamistikuna, millel toetudes saab implementeerida liidestusi erinevate analüsaatorite ja laboriinfosüsteemide jaoks.Data exchange with medical analyzers is an important requirement of any laboratory information system. Analyzers and the information system exchange data such as analysis results, orders and patient information. In high-throughput laboratories, clinical tests are performed around the clock, therefore manual data entry can become a bottleneck in their usual workflow. In order to increase the effectiveness of the lab staff and reduce the chance of human error, the data exchange has to be automated. Due to technical restrictions and the large number of communication protocols used by different analyzers, middleware software is often used to mediate communication between the information system and analyzers. An interruption in the data exchange can cause financial damage or even risk to life. Therefore, certain requirements should be considered during the implementation of such software to make it reliable and maintainable. This thesis gives an insight into the laboratory middleware field and builds a middleware prototype using the Akka toolkit. As a part of the prototype, an interface between a hypothetical analyzer and a laboratory information system is also implemented. The implemented prototype is used as a reference to analyze up to which extent Akka is suitable for implementing middleware software that satisfies requirements such as fault-tolerance, concurrency and code reusability. As a result, the prototype can be used as a minimal framework to connect additional analyzers with laboratory information systems

Representation Learning beyond Semantic Similarity: Character-aware and Function-specific Approaches

Representation learning is a research area within machine learning and natural language processing (NLP) concerned with building machine-understandable representations of discrete units of text. Continuous representations are at the core of modern machine learning applications, and representation learning has thereby become one of the central research areas in NLP. The induction of text representations is typically based on the distributional hypothesis, and consequently encodes general information about word similarity. Words or phrases with similar meaning obtain similar representations in a vector space constructed for this purpose. This established methodology excels for morphologically-simple languages such as English, and in data-rich settings. However, several useful lexical relations such as entailment or selectional preference, are not captured or get conflated with other relations. Another challenge is dealing with low-data regimes for morphologically-complex and under-resourced languages. In this thesis we construct novel representation learning methods that go beyond the limitations of the distributional hypothesis and investigate solutions that induce vector spaces with diverse properties. In particular, we look at how the vector space induction process influences the contained information, and how the information manifests in a number of core NLP tasks: semantic similarity, lexical entailment, selectional preference, and language modeling. We contribute novel evaluations of state-of-the-art models highlighting their current capabilities and limitations. An analysis of language modeling in 50 typologically-diverse languages demonstrates that representations can indeed pose a performance bottleneck. We introduce a novel approach to leveraging subword-level information in word representations: our solution lifts this bottleneck in low-resource scenarios. Finally, we introduce a novel paradigm of function-specific representation learning that aims to integrate fine-grained semantic relations and real-world knowledge into the word vector spaces. We hope this thesis can serve as a valuable overview on word representations, and inspire future work in modeling \textit{semantic similarity and beyond}.ERC Consolidator Grant LEXICAL (648909

Large-Eddy Simulation of Spatially Developing Aircraft Wake

Development of aircraft’s wake vortex from the roll-up until vortex decay is studied. An aircraft model and a surrounding flow field obtained from high-fidelity Reynolds Averaged Navier-Stokes simulation are swept through a ground fixed computational domain to initialize the wake. After the initialization, large-eddy simulation of the vortical wake is performed until vortex decay, i.e., 2-3 minutes after the passage of aircraft. Here, the methodology and some results from the simulations using the DLR-F6 wing-body model are presented

Scoring lexical entailment with a supervised directional similarity network

Scoring Lexical Entailment with a Supervised Directional Similarity NetworkERC Nvidi

Scoring lexical entailment with a supervised directional similarity network

Scoring Lexical Entailment with a Supervised Directional Similarity NetworkERC Nvidi