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Showing result 1 - 5 of 38 swedish dissertations matching the above criteria.

  2. 1. Interpretation of gamma-ray burst X-ray and optical afterglow emission : From the central engine to the circumburst interaction

    Author : Liang Li; Felix Ryde; Fawad Hassan; Kim Page; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; gamma-ray bursts; central engine; afterglow; teoretisk fysik; Theoretical Physics;

    Abstract : Gamma-ray bursts are the largest electromagnetic explosions known to happen in the Universe and are associated with the collapse of stellar progenitors into blackholes. After an energetic prompt emission phase, lasting typically less than a minute and emitted in the gamma-rays, a long-lived afterglow phase starts. READ MORE

  4. 2. Mining Web Logs to Improve User Experience in Web Search

    Author : Libertad Tansini; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Web log mining; web search; user intent; user recommendation; user modelling;

    Abstract : The World Wide Web continues to grow in size and diversity and this makes it increasinglyhard for users to find valuable information because of heterogeneous form and contentof the documents, little knowledge about the reliability and prestige of the documents anda great deal of redundancy.Usually search engines look for documents that contain specific keywords or phrasesstated by the users as queries. READ MORE

  5. 3. Supporting Scientific Collaboration through Workflows and Provenance

    Author : Tommy Ellqvist; Nahid Shahmehri; Paolo Missier; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Scientific collaboration; workflow; provenance; search engine; query language; data integration; Computer science; Datalogi;

    Abstract : Science is changing. Computers, fast communication, and  new technologies have created new ways of conducting research.  For  instance, researchers from different disciplines are processing and  analyzing scientific data that is increasing at an exponential rate. READ MORE

  6. 4. Parameter Estimation of a DOC from Engine Rig Experiments

    Author : Björn Lundberg; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multivariate Data Analysis; Parameter Estimation; Exhaust Aftertreatment Modeling; Design of Experiments; Engine Test Bench; DOC; Full Scale;

    Abstract : In this thesis methods of parameter estimation of a Diesel Oxidation Catalyst (DOC) from engine rig experiments were investigated. The investigation did not only include methods of parameter fitting to experimental data but a large effort was also put into catalyst modeling and experimental design. READ MORE

  7. 5. On the Design of Energy Efficient Aero Engines: Some Recent Innovations

    Author : Rickard Avellan; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbofan; aero engine; inter-turbine reheat; emissions; variable cycle; energy efficiency; propeller; NOx; MDO;

    Abstract : In the light of the energy crisis of the 1970s, the old aerospace paradigm of flying higher and faster shifted towards the development of more energy efficient air transport solutions. Today, the aeronautical research and development community is more prone to search for innovative solutions, in particular since the improvement rate of change is decelerating somewhat in terms of energy efficiency, which still is far from any physical limits of aero engine and aircraft design. READ MORE