Sökning: "short-time Fourier transform"

Visar resultat 1 - 5 av 16 uppsatser innehållade orden short-time Fourier transform.

  1. 1. Interharmonic Analysis of Sustainable Energy Sources and Loads : Comparing two signal processing methods for estimation of interharmonics

    Kandidat-uppsats, Högskolan Dalarna/Energiteknik

    Författare :Isabelle Löfgren; [2020]
    Nyckelord :interharmonics; short time Fourier transform; desynchronized processing technique; sliding-window ESPRIT; power quality; signal processing;

    Sammanfattning : In this report, studies on interharmonics from three different measurement sites are performed. The first site is a wind park with three turbines, where the measurements are performed at the point of common coupling of these three. LÄS MER

  2. 2. Predictive maintenance with machine learning on weld joint analysed by ultrasound

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Avdelningen för beräkningsvetenskap

    Författare :Adam Hedkvist; [2019]
    Nyckelord :Machine learning; AI; Ultrasound; Predictive maintenance; Industry 4.0;

    Sammanfattning : Ever since the first industrial revolution industries have had the goal to increase their production. With new technology such as CPS, AI and IoT industries today are going through the fourth industrial revolution denoted as industry 4.0. LÄS MER

  3. 3. Development of new criteria for train detection and evaluation in critical conditions

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Sofiane Kerbal; [2019]
    Nyckelord :railway signaling; train detection; track circuit; shunt; frequency modulation; frequency-shift keying modulation; third-order harmonic; short-time Fourier transform; power spectral density estimation; cross-correlation;

    Sammanfattning : Railway signaling is of paramount importance to ensure traffic management andsafety on the rail network. The main lines are divided into sections called ‘blocks’,which are governed by a fixed signal installation. To prevent trains from colliding,each block allows one train at once. LÄS MER

  4. 4. Time-frequency analysis of THz-time domain spectroscopy data

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Avdelningen för systemteknik

    Författare :Hugo Laurell; [2018]
    Nyckelord :;

    Sammanfattning : This text investigates THz-TDS signals in the time-frequency domain. Addi- tionally this text discusses the prospects of using time-frequency analysis to alleviate distortion in THz spectrographic characterizations induced by back- reflections in the free space electro optic sampling used in the THz time-domain spectroscopy detection scheme. LÄS MER

  5. 5. Corrosion initiation induced by sodium sulfate and sodium chloride particles on Cu and the golden alloy Cu5Al5Zn at simulated atmospheric conditions

    Master-uppsats, KTH/Materialvetenskap

    Författare :Weijie Zhao; [2017]
    Nyckelord :atmospheric corrosion; sodium sulfate; sodium chloride; Cu5Al5Zn; Cu metal; mixed salt pre-deposition; laboratory exposure; LOM; SEM EDS; ATR-FTIR; cathodic reduction;

    Sammanfattning : Effects of sodium sulfate (Na2SO4) particle deposition on the atmospheric corrosion of copper (Cu) metal and a Cu-based alloy (Cu5Al5Zn) used in architectural applications were investigated at laboratory conditions compared with effects induced by sodium chloride (NaCl) and to some extent ammonium sulfate (NH4)2SO4 induced corrosion. Pre-deposited surfaces were exposed to repeated wet/dry conditions in a climatic chamber and the formation of corrosion products were assessed using light optical microscopy (LOM), scanning electron microscopy with elemental analysis (SEM/EDS), Fourier transform infrared techniques (FTIR microscopy) and cathodic reduction (CR). LÄS MER