Search for dissertations about: "passive systems"

Showing result 21 - 25 of 296 swedish dissertations containing the words passive systems.

2. 21. Direct Ground Cooling Systems for Office Buildings

   Author : Taha Arghand; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ground heat exchangers; Energy renovation; Renewable energy; GeoTABS; Active chilled beams; Geocooling systems; TABS; ground-coupled cooling; Passive ground cooling; Thermal comfort; Direct ground cooling; Energy efficiency; Boreholes; Ceiling cooling panels; High-temperature cooling; Optimization; Comfort cooling;

   Abstract : The solving of crucial global energy challenges hinges on improving energy efficiency in building energy systems. Accomplishing energy-efficiency targets often entails incorporating sustainable energy sources into the energy supply system. READ MORE

4. 22. Characterization of Small Antennas & Wireless Devices for MIMO Systems in Multipath & Line-of-Sight

   Author : Ahmed Hussain; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; USRP; OTA; SDR; RIMP; TRP; TIS; Reverberation chamber; Rayleigh; MIMO; LOS; LTE; Throughput;

   Abstract : The current thesis investigates over-the-air (OTA) performance characterization of small antennas and wireless terminals in rich isotropic multipath (RIMP) environment, as well as in pure line-of-sight (LOS) environment when taking into account the random positions and orientations of the mobile terminals caused by the realistic user behavior. The latest mobile wireless terminals such as smart phones and tablets can be used in any random orientation thereby making even a received LOS-component appear as a random voltage at the antenna ports over time. READ MORE

5. 23. Inherent Safety Features and Passive Prevention Approaches for Pb/Bi-cooled Accelerator-Driven Systems

   Author : Johan Carlsson; KTH; []
   Keywords : Inherent Safety; Passive Safety; Accelerator-Driven Systems; ADS; nuclear waste; emergency decay heat removal; natural convection; thermal radiation;

   Abstract : This thesis is devoted to the investigation of passivesafety and inherent features of subcritical nucleartransmutation systems - accelerator-driven systems. The generalobjective of this research has been to improve the safetyperformance and avoid elevated coolant temperatures inworst-case scenarios like unprotected loss-of-ow accidents,loss-of-heat-sink accidents, and a combination of both theseaccident initiators. READ MORE

6. 24. Gap Waveguide: Low Loss Microwave Passive Components and MMIC Packaging Technique for High Frequency Applications

   Author : Ashraf Uz Zaman; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Quasi TEM; Slot Array; PMC; Gap waveguide; Narrow-band Filter;

   Abstract : The heavy congestion at the existing radio frequency spectrum allocated for the today’s wireless communications motivates and accelerates the research work at mmWave bands or even higher frequency range where more spectrum space is available for massive data rate delivery. The inclination of modern wireless system research and development is towards small size, reliable, high-performance and high-yield microwave multifunctional products. READ MORE

7. 25. Dynamic Resource Provisioning and Survivability Strategies in Optical Networks

   Author : Jawwad Ahmed; Lena Wosinska; Andrea Fumagalli; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optical networks; passive optical networks; wavelength; routing; Survivability; protection; restoration; SRA - ICT; SRA - Informations- och kommunikationsteknik;

   Abstract : Optical networks based on Wavelength Division Multiplexing (WDM) technology show many clear benefits in terms of high capacity, flexibility and low power consumption. All these benefits make WDM networks the preferred choice for today’s and future transports solutions which are strongly driven by a plethora of emerging online services. READ MORE