Sökning: "electrical impedance"

Visar resultat 6 - 10 av 240 avhandlingar innehållade orden electrical impedance.

  1. 6. Electrical impedance of human skin and tissue alterations : mathematical modeling and measurements

    Författare :Ulrik Birgersson; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Electrical impedance;

    Sammanfattning : The overall aim of the studies in this thesis is twofold. One is oriented towards calibrating a classifier in differentiating between malignant melanoma and benign nevi of the skin. LÄS MER

  3. 7. Characterization of Electrical Insulation Exposed to Arbitrary Voltage Waveforms

    Författare :Björn Sonerud; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; arbitrary voltage waveforms; partial discharge; diagnostics; dielectric response measurement; signal processing; electrical treeing; dielectric heating.;

    Sammanfattning : The extensive use of power electronics in power systems today gives rise to other voltage waveforms than the conventional 50/60 Hz sinusoidal and consequently other types of electric stress act on high voltage insulating materials. Previous studies has shown that Pulse Width Modulated (PWM) voltages and similar waveforms increase stress in Adjustable Speed Drives (ASD) as compared with sinusoidal waveforms and it has also been shown that partial discharge (PD) activity is intensified during PWM voltages and that rise time of square like pulses affect PD inception voltage. LÄS MER

  4. 8. Skin cancer as seen by electrical impedance

    Författare :Peter Åberg; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Electrical impedance; skin cancer; pattern recognition; screening;

    Sammanfattning : This thesis describes the relation between skin cancer and electrical impedance. On the cellular level, electrical impedance measured at clinically relevant frequencies is affected by e.g. LÄS MER

  5. 9. Analysis of dipole antennas in the presence of conducting cylindrical structures

    Författare :Peter Slättman; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; moment method; cylinder; dipole; fourier transform; mutual impedance; self impedance; basis function; through waveguide; EFIE;

    Sammanfattning : .... LÄS MER

  7. 10. Adaptive Programming of RFID Inlays in the Reactive Near Field

    Författare :Markus Frank; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; DTLL; RFID; UHF; RNF; Phase compensation; Phase shifting; Source Impedance Shift; Balun; FOM;

    Sammanfattning : Radio frequency identification (RFID) offers a vast variety of options to improve the functionality and efficiency in the automated data collection (ADC) industry and Internet of Things (IoT). In the inventory process of RFID with passive data carriers, a population of battery less tags is located in the working range of an interrogator system. LÄS MER