Search for dissertations about: "aperture efficiency"

Showing result 1 - 5 of 33 swedish dissertations containing the words aperture efficiency.

2. 1. Grouting of Hard Rock with Gelling Liquids, Field and Laboratory Studies of Silica sol

   Author : Johan Funehag; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; aperture; penetration length; gelling liquids; field study; silica sol; colloidal silica; Grouting; propagation; hydraulic test; sand column; rheology; transmissivity;

   Abstract : Recent grouting projects in Sweden have concentrated on the grout itself. The only grout normally used in Sweden is a cement-based one. During the past 10 years, the acceptable flow of water into tunnels has been significantly reduced. The current requirements mean that an average fracture aperture of around 0. READ MORE

4. 2. Grouting of Fractured Rock with Silica Sol; Grouting design based on penetration length

   Author : Johan Funehag; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Grouting; hydraulic test; sand column; propagation; penetration length; pipe flow; aperture; transmissivity; colloidal silica; silica sol; rheology; gelling liquids; field study;

   Abstract : ABSTRACTRecent grouting projects in Sweden have concentrated on the grout itself. The only grout normally used in Sweden is cement-based. During the past 10 years, the acceptable flow of water into tunnels has been reduced significantly. The current requirements mean that an average fracture aperture of around 0. READ MORE

5. 3. Towards Gap Waveguide Array Antenna for Millimeter Wave Applications

   Author : Abbas Vosoogh; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gap waveguide; Electric Discharge Machining EDM ; Artificial Magnetic Conductor AMC ; slot array antenna; low sidelobe; high effciency; millimeter wave; aperture efficiency; Bandpass filter BPF ;

   Abstract : The millimeter wave frequency range has got a lot of attention over the past few years because it contains unused frequency spectrum resources that are suitable for delivering Gbit/s end-user access in areas with high user density. Due to the limited output power that current RF active components can deliver in millimeter waves, antennas with the merits of low profile, high gain, high effciency and low cost are needed to compensate free space path loss and increase the communication distance for the emerging high data rate wireless systems. READ MORE

6. 4. High Efficiency Light Field Image Compression : Hierarchical Bit Allocation and Shearlet-based View Interpolation

   Author : Waqas Ahmad; Mårten Sjöström; Roger Olsson; Peter Schelkens; Mittuniversitetet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : Over the years, the pursuit of capturing the precise visual information of a scenehas resulted in various enhancements in digital camera technology, such as highdynamic range, extended depth of field, and high resolution. However, traditionaldigital cameras only capture the spatial information of the scene and cannot pro-vide an immersive presentation of it. READ MORE

7. 5. Efficient parallell architectures for future radar signal processing

   Author : Anders Åhlander; John L. Gustafson; Högskolan i Halmstad; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Computer architecture; radar signal processing; space-time adaptive processing; synthetic aperture radar; parallel processing; engineering efficiency; Computer science; Datalogi;

   Abstract : The processing demands on future embedded radar signal processors may stretch to several trillions of floating-point operations per second (TFLOPS). This is an increase of two to three orders of magnitude realtive to the requirements of today. Still, the tight size and power constraints are unchanged. READ MORE