Sökning: "Propagation Pattern Analysis"

Visar resultat 1 - 5 av 26 avhandlingar innehållade orden Propagation Pattern Analysis.

1. 1. Contact fatigue and crack propagation studies of sintered PM steel

   Författare :Anders Holmberg; Åsa Kassman Rudolphi; Urban Wiklund; Johan Ahlström; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tribology; PM steel; Fatigue; Crack Initiation; Crack Propagation; Material Analysis; Teknisk fysik med inriktning mot tribomaterial; Engineering Science with specialization in Tribo Materials;

   Sammanfattning : Gears made of PM steel are of interest for the automotive industry because from the press/sinter route, complex geometries can be produced to near net shape with only a few processing steps while keeping the material and energy usage at a minimum. However, the PM steels of today have significant performance limitations caused by the inherent porosity which impairs the mechanical properties by acting as stress raisers in the material. LÄS MER

3. 2. Spatial Characterization and Estimation of Intracardiac Propagation Patterns During Atrial Fibrillation

   Författare :Ulrike Richter; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrogram; Atrial Fibrillation; Propagation Pattern Analysis; Biomedical Signal Processing;

   Sammanfattning : This doctoral thesis is in the field of biomedical signal processing with focus on methods for the analysis of atrial fibrillation (AF). Paper I of the present thesis addresses the challenge of extracting spatial properties of AF from body surface signals. LÄS MER

4. 3. Biomechanical assessment of head and neck movements in neck pain using 3D movement analysis

   Författare :Helena Grip; Gertjan Ettema; Umeå universitet; []
   Nyckelord :movement analysis; kinematics; helical axis; neck pain; whiplash; cervical spine; pattern classification; motor control; head-eye co-ordination; head movement; biomedicinsk strålningsvetenskap; Biomedical Radiation Science;

   Sammanfattning : Three-dimensional movement analysis was used to evaluate head and neck movement in patients with neck pain and matched controls. The aims were to further develop biomechanical models of head and neck kinematics, to investigate differences between subjects with non-specific neck pain and whiplash associated disorders (WAD), and to evaluate the potential of objective movement analysis as a decision support during diagnosis and follow-up of patients with neck pain. LÄS MER

5. 4. Part Quality Prediction and Variation Reduction in Multistage Machining Processes Based on Skin Model Shapes

   Författare :Filmon Yacob; Daniel Semere; Sophie Gröger; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Machining simulation; model-based prediction; variation propagation; variation source identification; variation compensation; tolerance analysis; Octree; anomaly detection; quaternion; dual quaternion; Plücker coordinate.; Maskinbearbetningssimulering; modellbaseradförutsägelse; variationsspridning; variationskällidentifiering; variationskompensation; toleransanalys; Octree; dual quaternions; Plücker-koordinat.; Production Engineering; Industriell produktion;

   Sammanfattning : All manufacturing processes inevitably induce variations into manufactured parts that may result in nonconformance. Nonconforming parts incur costs due to the additional process required for rework or scrap loss. Hence, methodical efforts to reduce these variations are necessary for competitive manufacturing. LÄS MER

7. 5. Multiple Antenna Terminals in Realistic Environments - A Composite Channel Modeling Approach

   Författare :Fredrik Harrysson; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Channel model; MIMO; multiple antennas terminal; propagation; user interaction; vehicular channel; diversity; spatial multiplexing; channel measurement;

   Sammanfattning : For evaluation of specific antenna arrangements in wireless communication systems we need physical channel models that take into account also the directional domain of the propagation channel. In this thesis we investigate, validate and propose a practical approach to wireless channel modeling and, particularly, to mobile communication systems. LÄS MER