Sökning: "tåg"
Visar resultat 16 - 20 av 52 avhandlingar innehållade ordet tåg.
16. Expeditioner i det förflutna : etnologiska fältarbeten och försvinnande allmogekultur under 1900-talets början
Sammanfattning : In the first decades of the twentieth century there were fieldwork expeditions in rural Sweden, documenting archaic buildings and villages in words and pictures. These documentation efforts were part of a larger context, where the ambition was to survey and collect all aspects of what was presumed to be a vanishing peasant culture. LÄS MER
17. On Gate Drivers for MOS-Controlled Power Devices and dv-dt Filters for Train Traction Converters
Sammanfattning : In this thesis, low-loss gate-drive solutions and a proposed dv/dt-filter have been investigated with focus on train traction converters with dv/dt constraints.By using the silicon carbide (SiC) junction field-effect transistor (JFET), the switching losses can be significantly reduced compared to the commonly used insulated-gate bipolar transistor (IGBT), but complex gate-driver solutions are required for high utilization in terms of loss reduction. LÄS MER
18. Towards an efficient use of infrastructure and the built environment : Essays in transport and housing economics
Sammanfattning : All four papers in the thesis share a common theme: how to achieve an efficient use of infrastructure and the built environment. In the presence of externalities, pricing according to the (short-run) marginal cost is one answer on how this can be achieved and the first two papers estimates parts of the marginal cost of traffic. LÄS MER
19. Improving Timetable Robustness and Punctuality of Railway Traffic : A Combined Simulation-Optimization Approach for Nonperiodic Timetabling on Double-Track Lines
Sammanfattning : To evaluate the robustness of a timetable against minor delays, it can be simulated. A natural question following a simulation is how the results can be used to improve the timetable, which has received limited attention in the literature. LÄS MER
20. Intrinsic subtypes and prognostic implications in epithelial ovarian cancer
Sammanfattning : Ovarian cancer is the seventh most common cancer in women globally, with approximately 240,000 new cases annually. Although a rare disease, it is the most lethal gynecologic malignancy. Unspecific symptoms result in late diagnosis and a generally poor prognosis. LÄS MER
