Sökning: "space models"

Visar resultat 1 - 5 av 1013 avhandlingar innehållade orden space models.

1. 1. From meteors to space safety : dynamical models and radar measurements of space objects

   Författare :Daniel Kastinen; Johan Kero; Asta Pellinen-Wannberg; Mats Holmström; Detlef Koschny; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Meteors; meteor shower; atmosphere; meteoroids; meteoroid stream; small-body dynamics; solar system; comets; asteroids; near-Earth objects; space safety; space debris; radar; MU; EISCAT;

   Sammanfattning : Every day the Earth's atmosphere is bombarded by 10-200 metric tons of dust-sized particles and larger pieces of material from space called meteoroids. Dust and meteoroids come from parent bodies such as comets and asteroids, which are remnants from the formation of the solar system. LÄS MER

3. 2. Home, Job and Space : Mapping and Modeling the Labor Market

   Författare :John Östh; Bo Malmberg; Lena Magnusson; Stewart Fotheringham; Uppsala universitet; []
   Nyckelord :Social and economic geography; GIS; ELMO; Estimated Labor Market Outcome; Estimated Labour Market Outcome; Accessibility; Access; Job Accessibility; Place; Employment; Unemployment; Labour; Labor; Labor Market; Labour Market; Topology; Local Labour Market Area; Modelling; Modeling; Spatial Modelling; Spatial Modeling; Spatial Mismatch; SMH; Mismatch; Commuting; Regionalization; Geography; Population Geography; Economic Geography; Time-geography; Space; Kulturgeografi;

   Sammanfattning : How does space affect individuals’ outcome on the labor market? And how do we measure it? Beyond the notion of the labor market as a system of supply and demand, lays a society of individuals and workplaces, whose relationships are undeniably complex. This thesis aims to shed some new light on how to investigate and analyze the complex labor market relationships from a spatial perspective. LÄS MER

4. 3. Discrete Velocity Models and Half-Space Problems

   Författare :Niclas Bernhoff; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boltzmann equation; discrete velocity models; half-space problems; Matematik; Mathematics;

   Sammanfattning : We study some questions related to discrete velocity models (DVMs) of the Boltzmann equation. In the case of plane stationary problems the typical DVM reduces to a dynamical system (system of ODEs). Properties of such systems are studied in this paper in the most general case. LÄS MER

5. 4. Tensionless Strings and Supersymmetric Sigma Models : Aspects of the Target Space Geometry

   Författare :Andreas Bredthauer; Ulf G. Lindström; Bengt E.W. Nilsson; Uppsala universitet; []
   Nyckelord :Theoretical physics; Theoretical Physics; String Theory; Tensionless Strings; Supergravity Backgrounds; Plane Wave; Supersymmetry; Non-linear Sigma Models; Generalized Complex Geometry; Teoretisk fysik;

   Sammanfattning : In this thesis, two aspects of string theory are discussed, tensionless strings and supersymmetric sigma models.The equivalent to a massless particle in string theory is a tensionless string. Even almost 30 years after it was first mentioned, it is still quite poorly understood. LÄS MER

7. 5. Numerical modelling of ENAs from stellar wind interactions

   Författare :Andreas Ekenbäck; Mats Holmström; Michael R. Collier; Institutet för rymdfysik (IRF); []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Space physics; Space technology; Astrophysics; Space engineering; Rymdteknik;

   Sammanfattning : Energetic neutral atoms (ENAs) are produced whenever a stellar wind encounters a neutral atmosphere. If a stellar wind proton comes sufficiently close to a neutral a charge-exchange reaction may take place, transforming the proton into an ENA. LÄS MER