Search for dissertations about: "active and passive Measurements"

Showing result 11 - 15 of 63 swedish dissertations containing the words active and passive Measurements.

2. 11. Experimental and Numerical Multi-port Eduction for Duct Acoustics

   Author : Stefan Sack; Abom Mats; Phillip Joseph; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acoustics; aeroacoustics; flowacoustics; multi-ports; orifice; silencer; experiment; numeric; IDDES; LNSE; optimization; test rig; Monte Carlo; Teknisk mekanik; Engineering Mechanics;

   Abstract : Sound generation and propagation in circular ducts for frequencies beyond the cut-on frequencies of several higher order acoustic modes is investigated. To achieve this, experimental and numerical set-ups are designed and used to research aeroacoustic interactions between in-duct components and to conceive noise mitigation strategies. READ MORE

4. 12. A Database of Microwave Single Scattering Properties of Ice Hydrometeors

   Author : Robin Nils Ekelund; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; radar; ice hydrometeors; microwave; scattering properties; sub-millimetre; remote sensing;

   Abstract : Microwave remote sensing by satellites is important for global observations of ice hydrometeors. Interpretation of the measurements requires sufficiently accurate knowledge of hydrometeors’ interaction with photons, i.e.  article scattering and absorption. READ MORE

5. 13. Characterisation and Modelling of Graphene FETs for Terahertz Mixers and Detectors

   Author : MICHAEL ANDERSSON; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; graphene; millimetre and submillimetre waves; power detectors; nonlinear device modelling; microwave amplifiers; nanofabrication; integrated circuits; noise modelling; Field-effect transistors FETs ; terahertz detectors; Volterra; subharmonic resistive mixers;

   Abstract : Graphene is a two-dimensional sheet of carbon atoms with numerous envisaged applications owing to its exciting properties. In particular, ultrahigh-speed graphene field effect transistors (GFETs) are possible due to the unprecedented carrier velocities in ideal graphene. READ MORE

6. 14. On Rail Vehicle Dynamics in Unsteady Crosswind Conditions : Studies Related to Modelling, Model Validation and Active Suspension

   Author : Dirk Thomas; Berg Mats; Sebastian Stichel; Jordi Vinolas; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Järnvägsgruppen - Fordonsteknik; Järnvägsgruppen - Fordonsteknik;

   Abstract : Crosswind stability of rail vehicles has been a research area for several decades, mainlymotivated by vehicle overturning accidents and higher speeds, but in recent times also byissues of lower energy consumption and track maintenance costs demanding lower vehi-cle weights. During everyday operation, rail vehicles are subjected to substantial lateralinfluences from track curves, track irregularities and crosswind, leading to large suspen-sion deflections and increased crosswind sensitivity. READ MORE

7. 15. Energy Efficient Protocols for Active RFID

   Author : Björn Nilsson; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; wake-up radio; energy consumption; energy efficient; Active RFID; protocol; RFID; throughput; back-off; RFID-system; delay;

   Abstract : Radio frequency identification (RFID) systems come in different flavours; passive, active, semi-passive, or semi-active. Those different types of RFID are supported by different, internationally accepted protocol standards as well as by several accepted proprietary protocols. READ MORE