Sökning: "vindar"

Visar resultat 11 - 15 av 16 avhandlingar innehållade ordet vindar.

1. 11. Migration strategies of raptors – spatio-temporal adaptations and constraints in travelling and foraging

   Författare :Roine Strandberg; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; route convergence; loop migration; mortality; spatio-temporal distribution patterns; pre- and post-migratory movements; daily travel routines; satellite tracking; fly-and-forage migration; raptors;

   Sammanfattning : My dissertation is about bird migration and addresses questions about how raptors adapt to the fluctuating environments during the transition seasons between breeding and wintering. The migration is highly affected by local prey abundance, foraging strategies, weather conditions and landscape patterns along the migration routes as well as navigation and orientation mechanisms and cues. LÄS MER

3. 12. Tracking the Wanders of Nature

   Författare :Clas Veibäck; Gustaf Hendeby; Fredrik Gustafsson; Hans Driessen; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Target Tracking; Sensor Fusion; Motion Models; Animals; Cameras; Radar;

   Sammanfattning : Target tracking is a mature topic with over half a century of mainly military and aviation research. The field has lately expanded into a range of civilian applications due to the development of cheap sensors and improved computational power. LÄS MER

4. 13. On Incentives affecting Risk and Asset Management of Power Distribution

   Författare :Carl Johan Wallnerström; Rajeev Thottappillil; Patrik Hilber; Ulf Sandberg; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; asset management; correlation studies; incentives; investment planning; maintenance planning; power distribution; reliability analysis; risk management; statistical validation; tariff regulation; vulnerability analysis; weather states; Electric power engineering; Elkraftteknik; Mathematical statistics; Matematisk statistik; Industrial engineering and economy; Industriell teknik och ekonomi;

   Sammanfattning : The introduction of performance based tariff regulations along with higher media and political pressure have increased the need for well-performed risk and asset management applied to electric power distribution systems (DS), which is an infrastructure considered as a natural monopoly. Compared to other technical systems, DS have special characteristics which are important to consider. LÄS MER

5. 14. Flight Behaviour of Passerines on Nocturnal Migration

   Författare :Cecilia Nilsson; Evolutionär ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bird migration; Passerines; Flight Behaviour; Tracking radar; Optimal migration; Flight speed; Airspeed; Wind drift; Nocturnal migration; Coastline effects; Flight directions; Reverse migration;

   Sammanfattning : Many passerines migrate during the night and at high altitudes, making their migration difficult to observe. By using tracking radars we have been able to make exact observations of the flight behaviour of passerines on nocturnal migration, which has enabled us to test several hypotheses about adaptive values and constraints regarding migratory behaviour in different ecological contexts. LÄS MER

7. 15. Bird orientation: external cues and ecological factors

   Författare :Johan Bäckman; Evolutionär ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; tracking radar; Emlen funnel.; Animal ecology; Djurekologi; oscillatory orientation; roosting flight; scatter; concentration; heading; cue calibration; light dependent; magnetoreception; subcutaneous fat stores; body condition; energetics; geomagnetic field; visual cues; orientation; birds; migration;

   Sammanfattning : Birds are generally capable of accurate orientation. In this thesis I present studies about the external cues and the ecological factors that influences bird orientation. A multitude of environmental cues are used to select and maintain a proper direction. LÄS MER