Sökning: "heading"

Visar resultat 1 - 5 av 57 avhandlingar innehållade ordet heading.

1. 1. 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

3. 2. Where are the world’s disease patterns heading? : The challenges of epidemiological transition

   Författare :Ailiana Santosa; Peter Byass; Ulf Högberg; Joacim Rocklöv; Sarah Wild; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; epidemiological transition; premature mortality; non-communicable disease; risk factors; Sweden; low-and middle-income countries; INDEPTH Network; Västerbotten Intervention Programme; Public health; folkhälsa;

   Sammanfattning : INTRODUCTION: Epidemiological transition theory, first postulated by Omran in 1971, provides a useful framework for understanding cause-specific mortality changes and may contribute usefully to predictions about cause-specific mortality. However, understandings of mortality transitions and associated epidemiological changes remain poorly defined for public health practitioners due to lack of evidence from low- and middle-income countries. LÄS MER

4. 3. Autonomous Localization in Unknown Environments

   Författare :Jonas Callmer; Fredrik Gustafsson; Paul Havinga; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Localization; indoor positioning; heading estimation; magnetometers;

   Sammanfattning : Over the last 20 years, navigation has almost become synonymous with satellite positioning, e.g. the Global Positioning System (GPS). On land, sea or in the air, on the road or in a city, knowing ones position is a question of getting a clear line of sight to enough satellites. LÄS MER

5. 4. A Model of Driver Perception and Action in Intersections

   Författare :Anna Bjelkemyr; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; intersection; vehicle heading; driving; behavior; driver; perception; eye movement; anticipate;

   Sammanfattning : The objective of the research presented in this thesis is to describe driver behavior while approaching, entering and exiting an intersection. To fulfill this objective, two semi-naturalistic studies were conducted where ten driver participants drove a test vehicle through a three-way intersection repeatedly, driving straight, turning left, and turning right in a total of six possible passes. LÄS MER

7. 5. Keep it rolling : Straight-line orientation in South African ball-rolling dung beetles

   Författare :Lana Khaldy; Funktionell zoologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ball-rolling dung beetle; Orientation; Heading direction network; Compass; Weighting; Celestial cues; Sun; Polarised light;

   Sammanfattning : Representing a substantial range and variety in morphological and ecological niche, found on all continents of the globe (except for the Antarctic), the ball-rolling dung beetles provide an excellent model in which to study the heading direction network and the factors by which it is influenced. As soon as a ball-rolling dung beetle has located a fresh dung pile to feed on, it immediately starts shaping a piece of dung into a ball, rolling it away from the dung pat in as straight of a trajectory as the terrain allows. LÄS MER