Essays about: "HF"

Showing result 6 - 10 of 74 essays containing the word HF.

  1. 6. Automated Measurement of Relative HF Antenna Properties using WSPR

    University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Author : Axel Blomqvist; [2023]
    Keywords : ;

    Abstract : The performance of antennas is an important factor in creating a well performing radio communication channel. Traditionally measuring High Frequency (HF) antennas is an expensive and complicated process. J. Zander[1] proposes an alternative method of evaluating antenna performances in the HF band. READ MORE

  3. 7. Design and implementation of an energy harvesting system in a prosthetic limb

    University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Author : Ódinn K. Rúnarsson; [2023]
    Keywords : Energy harvesting; Prosthetic limbs; Supercapacitors; Printed circuit boards; 3D printing; Energiinsamling; Lemmproteser; Superkondensatorer; Tryckta kretskort; 3D Utskrivning; Orkuöflun; Gervilimir; Ofurþéttar; Prentaðar rafrásir; Þrívíddarprentun;

    Abstract : Energy Harvesting, also known as power harvesting or ambient power, is the process of obtaining small amounts of power from secondary sources, such as vibrations, light, temperature variations and even radio-frequency emissions. These systems have been uncommon in personal and wearable electronics in the past, however they are slowly gaining traction. READ MORE

  4. 8. Cultivating oleaginous yeast on spent mushroom substrate and logging residues hydrolysate : an assessment of yeast growth on side product substrates from the food, agriculture, and forestry industry

    University essay from SLU/Department of Molecular Sciences

    Author : Robin Lukic; [2023]
    Keywords : Lignocellulose; side products; oleaginous yeast; yeast oil; microtiter plate system; redox indicator; yeast growth; spent mushroom substrate hydrolysate; logging residues hydrolysate;

    Abstract : There is an interest in finding alternatives to vegetable oils because of negative environmental impact. Many green sectors generate an abundant amount of side products that are inedible and consist in large of lignocellulose rich materials. READ MORE

  5. 9. Estimation of respiratory frequency from Heart Rate Variability

    University essay from Lunds universitet/Matematisk statistik

    Author : Daniel Ågärd; [2023]
    Keywords : time-frequency analysis; multitaper spectrogram; Optimization; signal processing; heart rate variability; Mathematics and Statistics;

    Abstract : In this master's thesis the ability to estimate the respiratory frequency from heart rate variability measurement is analyzed. The goal was to implement a solution that is easily transferable to real time. READ MORE

  6. 10. Antenna measurements of HF antennas using low cost UAVs

    University essay from KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Author : Ruimin Ma; Jinting Zhang; [2023]
    Keywords : Antenna; HF; UAV; Radiation Pattern; Antenna; HF; UAV; Strålningsmönster;

    Abstract : High-frequency signal far-field measurement systems usually involve the use of complex and expensive equipment, since the measurements must be made at a distance of multiple wavelengths from the antenna. Helicopter surveyors are commonly utilized. READ MORE