Sökning: "high-frequency measurement"
Visar resultat 21 - 25 av 87 avhandlingar innehållade orden high-frequency measurement.
21. Attenuation of hand-held machine vibrations. Application of non-linear tuned vibration absorber
Sammanfattning : Vibration injury in the hand-arm system from vibrating hand-held machines is one of the most common occupational health injuries and causes severe and often chronic nerve and vascular injuries to the operator. The objective with this study is to contribute to reduce hand-arm vibration injuries, first by developing methods of redesigning machines that will lower their vibration level and second to study how high frequency vibrations (HFV) above 1250 Hz effect the finger tissue which are not included in the current standard for risk evaluation. LÄS MER
22. Liquidity and Portfolio Optimisation
Sammanfattning : This thesis presents research within empirical financial economics with focus on liquidity and portfolio optimisation in the stock markets. The discussion on liquidity is focussed on measurement issues, including TAQ data processing and measurement of systematic liquidity factors. LÄS MER
23. Application of high-frequency mechanical impact treatment for fatigue strength improvement of new and existing bridges
Sammanfattning : This thesis investigates the application of High-Frequency Mechanical Impact (HFMI) treatment for fatigue strength improvement of weldments in existing and new bridges. In the former case, the welds have already been subjected to fatigue loading and accumulated damage before treatment. LÄS MER
24. High Frequency Elastic Wave Emission Caused by a Single Elastohydrodynamically Lubricated Contact: Fundamental sources and Principles
Sammanfattning : Elastohydrodynamically lubricated (EHL) contacts are fundamental for severalrotating machine elements. For example gears, rolling element bearingsand lubricated chain drives work due to the principle of EHL. LÄS MER
25. Nonlinear Characterisation and Modelling of Microwave Semiconductor Devices
Sammanfattning : There is an increasing need for more accurate models taking into account the nonlinearities and memory effects of microwave transistors. The memory effects are especially important for transistor technologies suffering from relatively large low frequency dispersion, such as GaN baed HEMTs. LÄS MER