Search for dissertations about: "short time Fourier transform"

Showing result 1 - 5 of 18 swedish dissertations containing the words short time Fourier transform.

  2. 1. Fourier transform and Vernier spectroscopy using optical frequency combs

    Author : Amir Khodabakhsh; Aleksandra Foltynowicz; Ove Axner; Frans Harren; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; optical frequency comb spectroscopy; molecular absorption; resonant cavity; Fourier transform spectroscopy; Vernier spectroscopy; fysik; Physics;

    Abstract : Optical frequency comb spectroscopy (OFCS) combines two previously exclusive features, i.e., wide optical bandwidth and high spectral resolution, enabling precise measurements of entire molecular bands and simultaneous monitoring of multiple gas species in a short measurement time. READ MORE

  4. 2. Stability and Statistical Analysis of Transient Waves in Fusion Plasmas

    Author : Gergö Pokol; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; short-time Fourier transform; transient MHD mode; wavelet transform; quasi-linear diffusion; runaway electron; transient transport; stellarator; tokamak disruption; fusion plasma physics; whistler wave;

    Abstract : Thermonuclear energy generation in magnetically confined plasmas offers an appealing energy source for coming generations. Some of the still unsolved problems in fusion plasma physics involve plasma transport and stability of plasma waves. Two such problems are addressed in the present thesis. READ MORE

  5. 3. High Resolution Spectroscopy of Singly Charged Ions : Applications of Laser and Fourier Transform Techniques

    Author : Jonas Gurell; Sven Mannervik; Richard Holt; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Atomic physics; Atomfysik; fysik; Physics;

    Abstract : This thesis presents measurements of fundamental properties of singly charged ionic systems including spectral wavelengths, lifetimes of excited states and branching fractions with the main focus on time resolved laser spectroscopy of stored ions providing lifetime measurements of metastable states. The results of these measurements have been used to determine energy levels and transition probabilities of the studied systems. READ MORE

  6. 4. Adapting Bases Using the Synchronized Short Time Fourier Transform and Non-negative Matrix Factorization

    Author : Ruairí de Fréin; Scott T. Rickard; Barak A. Pearlmutter; University College Dublin; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tillämpad matematik och beräkningsmatematik; Applied and Computational Mathematics;

    Abstract : .... READ MORE

  7. 5. DIGITAL ANALYSIS OF CARDIAC ACOUSTIC SIGNALS IN CHILDREN

    Author : Milad El-Segaier; Lund Pediatrik; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pediatri; Medicin människa och djur ; Cardiovascular system; Kardiovaskulära systemet; Pediatrics; Medicine human and vertebrates ; Heart sound detection; Logistic regression; Receiver operating characteristic curve; Signal deconvolution.; Short-time Fourier transform; Cardiac acoustic signals; Time interval measurements;

    Abstract : DIGITAL ANALYSIS OF CARDIAC ACOUSTIC SIGNALS IN CHILDREN Milad El-Segaier, MD Division of Paediatric Cardiology, Department of Paediatrics, Lund University Hospital, Lund, Sweden SUMMARY Despite tremendous development in cardiac imaging, use of the stethoscope and cardiac auscultation remains the primary diagnostic tool in evaluation of cardiac pathology. With the advent of miniaturized and powerful technology for data acquisition, display and digital signal processing, the possibilities for detecting cardiac pathology by signal analysis have increased. READ MORE