Search for dissertations about: "cut off"

Showing result 1 - 5 of 355 swedish dissertations containing the words cut off.

2. 1. Cut-off and coordinated survey sampling

   Author : Kira Coder Gylling; Thomas Laitila; Nicklas Pettersson; Martin Axelson; Örebro universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Statistik; Statistics;

   Abstract : The problem of estimation from a sample is well known and its solutions are the foundation for the sample surveys conducted at e.g. national statistical institutes. This dissertation looks at the estimation problem from the perspective of business survey methodology. READ MORE

4. 2. Control and Optimization of Fuel Cell Based Powertrain for Automotive Applications

   Author : Qian Xun; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power distribution; Cut-off frequency; Fuel cell; Chance-constraint co-design optimization; Supercapacitors; Convex programming; Electric vehicles; Load disturbance compensator; DC-link voltage; Robust co-design optimization; Batteries;

   Abstract : Fuel cell powered electric vehicles, with fast-refueling time, high energy density, and zero CO2 emissions, are becoming a promising solution for future fossil-free transportation. However, the relatively slow dynamic response and the inability of recovering the regenerative energy make vehicles solely powered by fuel cells not an immediately attractive solution. READ MORE

5. 3. Lithium-ion batteries for off-grid PV-systems

   Author : Fabian Benavente; Göran Lindbergh; Anders Olof Lundblad; Saul Cabrera; Daniel Abraham; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Lithium-ion batteries; aging; partial cycles; DVA; EIS; NCA; stationary energy systems; PV systems; rural electrification.; Chemical Engineering; Kemiteknik;

   Abstract : This thesis provides a comprehensive and detailed analysis on the effect ofthe battery operation strategy on the lifetime of commercial lithium-ionbatteries and on the economics of off-grid photovoltaic (PV)-batterysystems.Lithium-ion batteries play a key role in the transition to a fossil-freesociety. READ MORE

6. 4. Contribution to Numerical and Experimental Studies of Flutter in Space Turbines. Aerodynamic Analysis of Subsonic or Supersonic Flows in Response to a Prescribed Vibratory Mode of the Structure

   Author : Hakim Ferria; Pascal Ferrand; Torsten Fransson; François Moyroud; France Ecole Centrale de Lyon Laboratoire de Mécanique des Fluides et d'Acoustique; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flutter; space turbine; LRANS computation; flutter measurement; shock wave boundary layer interaction; blisk; cut-on cut-off condition; interblade phase angle; combined modes;

   Abstract : Modern turbomachines are designed towards thinner, lighter and highly loaded blades. This gives rise to increased sensitivity to flow induced vibrations such as flutter, which leads to structure failure in a short period of time if not sufficiently damped. READ MORE

7. 5. Fracture behaviour and related microstructures of tool steels parted-off at high rates of strain

   Author : Kristina Ryttberg; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-velocity parting-off; adiabatic cutting; high strain-rate deformation; TEM; steel; adiabatic shear band;

   Abstract : Increasing steel prices and environmental aspects have put forward the demand to reduce material consumption in manufacturing industry and near-net-shape manufacturing techniques have thus become increasingly important. High-velocity parting-off, or adiabatic cutting, has shown to result in very low material waste as well as narrow dimensional tolerances of parted-off samples. READ MORE