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Showing result 1 - 5 of 100 swedish dissertations matching the above criteria.

2. 1. Spectral Mammography with X-Ray Optics and a Photon-Counting Detector

   Author : Erik Fredenberg; Mats Danielsson; Björn Cederström; Jeffrey H. Siewerdsen; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; mammography; x-ray optics; photon counting; spectral shaping; spectral imaging; collimation; radiation dose; signal-to-noise ratio; quantum noise; anatomical noise; spatial resolution; x-ray flux; ; TECHNOLOGY; TEKNIKVETENSKAP; Engineering physics; Teknisk fysik; Optical physics; Optisk fysik; Other engineering physics; Övrig teknisk fysik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik; Medical engineering; Medicinsk teknik; Radiological research; Radiologisk forskning;

   Abstract : Early detection is vital to successfully treating breast cancer, and mammography screening is the most efficient and wide-spread method to reach this goal. Imaging low-contrast targets, while minimizing the radiation exposure to a large population is, however, a major challenge. READ MORE

4. 2. Recognition of printed Sinhala characters by direction fields

   Author : Hemakumar Lalith Premaratne; Högskolan i Halmstad; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; HUMANIORA; HUMANITIES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Printed Sinhala characters; Electronics; Photonics; TECHNOLOGY; TEKNIKVETENSKAP;

   Abstract : Although substantial research has been carried out on Optical Character Recognition (OCR) where a printed or a handwritten document of script is read as an image and converted to the editable text format, for various languages during the last 30 years, majority of Brahmi descended south Asian scripts are yet to achieve a commercial OCR system.... READ MORE

5. 3. VCSEL Cavity Engineering for High Speed Modulation and Silicon Photonics Integration

   Author : Emanuel Haglund; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-speed modulation; on-chip laser source; vertical-cavity surface-emitting laser VCSEL ; semiconductor lasers; optical interconnects; large signal modulation; laser dynamics; heterogeneous integration; vertical-cavity silicon-integrated laser VCSIL ; silicon photonics;

   Abstract : The GaAs-based vertical-cavity surface-emitting laser (VCSEL) is the standard light source in today's optical interconnects, due to its energy efficiency, low cost, and high speed already at low drive currents. The latest commercial VCSELs operate at data rates of up to 28 Gb/s, but it is expected that higher speeds will be required in the near future. READ MORE

6. 4. High resolution electrical characterization of III-V materials and devices

   Author : Olivier Douheret; Srinivasan Anand; Wilfried Vandervorst; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; condensed matter; electrics; electrical; materials science; Elektroteknik; elektronik och fotonik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

   Abstract : The continuing shrinkage of semiconductor devices towards nanoscale features and increased functionality has prompted a strong need for high-resolution characterization tools capable of mapping the electrical properties with nanoscale lateral resolution. In this regard, scanning capacitance microscopy (SCM) scanning spreading resistance microscopy (SSRM) and Kelvin probe force microscopy (KPFM) have emerged as powerful techniques. READ MORE

7. 5. Upconversion in Er doped silica : - characterization and modeling

   Author : Dmitry Khoptyar; Bozena Jaskorszynska; Anders Bjarklev; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; Elektroteknik; elektronik och fotonik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

   Abstract : Further increase of erbium concentrations in Er-doped amplifiers and lasers is needed for the design of efficient, reliable, compact and cost-effective components for telecommunications and other photonic applications. However, this is hindered by Er concentration dependent loss mechanism known as upconversion. READ MORE