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Control of a III-V MOCVD Process using Ultraviolet Absorption and Ultrasonic Concentration Monitoring
(2001)IEEE Transactions on Control Systems TechnologyMetalorganic chemical vapor deposition (MOCVD) is a key technology for the growth of compound semiconductors. This process has traditionally lacked real-time growth monitoring and control, which limits the precise reproducibility needed for high performance devices. Two complementary control approaches for the MOCVD process are investigated experimentally. The first is a feedforward disturbance rejection strategy using ultrasonic ...Journal Article -
Outdoor Walking Speeds of Apparently Healthy Adults: A Systematic Review and Meta-analysis
(2021)Sports MedicineBackground: Walking outdoors can be used by many individuals to meet public health guidelines for moderate-to-vigorous intensity physical activity. The speed at which adults walk may be a proxy for intensity. Traditional estimates of indoor walking speed are unlikely to reflect self-selected usual or other instructed paces of outdoor walking speed.Journal Article -
Control of Deep Space Formation Flying Spacecraft; Relative Sensing and Switched Information
(2005)Journal of Guidance, Control, and DynamicsSpacecraft formations in deep space can be specified in terms of the relative spacecraft positions and absolute spacecraft orientations. Accurate absolute position measurements are not available and a formation control design approach, based on relative position information, is presented. This approach exploits the redundancy inherent in a relative position specification to develop a family of equivalent control topologies for optimal ...Journal Article -
Anpassungsstrategien für produktive Fichtenwälder
(2023)AFZ - DerWaldDer Klimawandel mit großflächigen Schadereignissen stellt den zukünftigen Fichtenanbau selbst in montanen Lagen in Frage. Strategien zur Anpassung an die Ausfallrisiken der Fichte sind dringend gesucht. Dieser Beitrag vergleicht Anpassungsoptionen mit dem Ziel, heutige monetäre Erfolgsaussichten bei montanen Fichtenstandorten zu erhalten.Journal Article -
Severe and frequent extreme weather events undermine economic adaptation gains of tree-species diversification
(2024)Scientific ReportsForests and their provision of ecosystem services are endangered by climate change. Tree-species diversification has been identified as a key adaptation strategy to balance economic risks and returns in forest stands. Yet, whether this synergy between ecology and economics persists under large-scale extreme weather events remains unanswered. Our model accounts for both, small-scale disturbances in individual stands and extreme weather ...Journal Article -
Simulation of silvicultural treatments based on real 3D forest data from mobile laser scanning point clouds
(2023)Trees, Forests and PeopleForest management has a direct influence on the structure and stability of forests. In this study, we used the 3D data from mobile laser scanning in real forest stands dominated by European beech (Fagus sylvatica L.) to simulate different silvicultural treatments and assess their impact on the structural complexity and short-term economic return. For the structural assessment, we used the box-dimension (Db), a holistic measure of structural ...Journal Article -
optimLanduse : A package for multiobjective land‐cover composition optimization under uncertainty
(2022)Methods in Ecology and Evolution1. How to simultaneously combat biodiversity loss and maintain ecosystem functioning while improving human welfare remains an open question. Optimization approaches have proven helpful in revealing the trade-offs between multiple functions and goals provided by land-cover configurations. The R package optimLanduse provides tools for easy and systematic applications of the robust multiobjective land-cover composition optimization approach ...Journal Article -
Optimizing nitrogen use efficiency of six forage grasses to reduce nitrogen loss from intensification of tropical pastures
(2024)Agriculture, Ecosystems & EnvironmentWe aimed to evaluate the effect of different types and rates of nitrogen (N) fertilizers on plant biomass production, nitrogen use efficiency (NUE), and nitrous oxide (N2O) emissions of six tropical forage grass cultivars. This field study was conducted in Colombia under tropical conditions in two phases. Phase 1: we evaluated the effect of different types of N fertilizers (urea; calcium ammonium nitrate (CAN); and urea-ammonium sulfate ...Journal Article -
Parallel adaptation in autopolyploid Arabidopsis arenosa is dominated by repeated recruitment of shared alleles
(2021)Nature Communicationselative contributions of pre-existing vs de novo genomic variation to adaptation are poorly understood, especially in polyploid organisms. We assess this in high resolution using autotetraploid Arabidopsis arenosa, which repeatedly adapted to toxic serpentine soils that exhibit skewed elemental profiles. Leveraging a fivefold replicated serpentine invasion, we assess selection on SNPs and structural variants (TEs) in 78 resequenced ...Journal Article -
Truncation effects in the functional renormalization group study of spontaneous symmetry breaking
(2015)Journal of High Energy PhysicsWe study the occurrence of spontaneous symmetry breaking (SSB) for O(N ) models using functional renormalization group techniques. We show that even the local potential approximation (LPA) when treated exactly is sufficient to give qualitatively correct results for systems with continuous symmetry, in agreement with the Mermin-Wagner theorem and its extension to systems with fractional dimensions. For general N (including the Ising model ...Journal Article