• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 213
  • 75
  • 24
  • 21
  • 12
  • 12
  • 10
  • 9
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • Tagged with
  • 476
  • 154
  • 110
  • 103
  • 89
  • 64
  • 56
  • 55
  • 52
  • 49
  • 43
  • 38
  • 37
  • 35
  • 34
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Subarea determination of the capacitance of a toroid

Carroll, D. P. January 1965 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 69-75.

Toroidalization of locally toroidal morphisms

Hanumanthu, Krishna Chaithanya, January 2008 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on June 8, 2009) Vita. Includes bibliographical references.

Die Nullstellen des allgemeinen integrals der Differentialgleichung für die zugeordneten Kugelfunktionen ...

Lindow, Martin Paul Johannes, January 1902 (has links)
Inaug.-diss.--Halle. / Lebenslauf.

Studien über die Kugel- und Cylinderfunctionen ...

Olbricht, Richard, January 1887 (has links)
Inaug.-diss.--Leipzig. / Lebenslauf.

Studien über die Kugel- und Cylinderfunctionen

Olbricht, Richard, January 1887 (has links)
Published also as inaugural dissertation, Leipzig, 1887. / "Eingegangen bei der Akademie am 2. Juni 1886." Bibliographical foot-notes.

The accurate analysis of smoothly fluctuating harmonics applied to the calibration of harmonic analysers

Wright, P. S. January 2002 (has links)
The aim of this research is to develop an accurate method for the analysis of signals composed of fluctuating harmonics. The results obtained of analysis are applied to the calibration of harmonic analysis instruments. A new method is presented suitable for the accurate analysis of smoothly fluctuating harmonic signals. The method is based on a model of signals with a known period, in which the harmonics are individually modulated by polynomial functions normalised over a sampled signal sequence time. Using this model, a decomposition method is developed such that the modulating polynomials can be recovered from a signal. The polynomial decomposition method leads to a piece-wise analysis of the waveform. Two methods based on least squares and splines respectively, are developed with the aim of giving continuity to the piece-wise analysis. Comparisons of the new method with the short time Fourier transform are given. Having defined a test signal and obtained and accurate analysis of it properties, it can be used to calibrate harmonic analysers. For a given applied signal, analysis with these devices can give rise to variation in results as a function of the phase between the signal and the STFT windows. This result distribution due to variable phase (RDVP) is discussed and examples are given for various signals. The RDVP complicates the calibration process due to the spread of results that occur when testing the device. A method is developed to find the RDVP for an applied signal that uses the polynomial decomposition method to find the modulation functions of each harmonic in the applied calibration signal. Having found the RDVP for an applied signal, it is necessary to fit the results of the analyser under test, to the distribution. The random nature of the phase makes the systematic comparison of the theoretical and measured distributions difficult to achieve. A novel method that uses multiple phase shifted modulated harmonics is presented. By comparing the results of the analyser under test to the distributions of each of the phase-shifted harmonics, a best-fit phase shift can be determined and the required calibration comparison made. Key words: time-frequency analysis, demodulation, harmonic analysis, fluctuating harmonics, waveform metrology, calibration of harmonic analysers.

Extreme Ultraviolet Hyperspectral Coherent Diffractive Imaging

Yijian, Meng January 2015 (has links)
We demonstrate hyperspectral imaging using two time-delayed, coherent extreme ultraviolet (XUV) sources. The approach combines broadband XUV high-harmonic generation, holographic imaging, and Fourier transform spectroscopy. The two harmonics sources are spatially separated at generation,and overlap in the far field resulting in a double slit diffraction pattern. We record the two-dimensional intensity modulation as a function of relative time delay; the Fourier transform determines the spatially dependent spectrum. To reduce the delay jitter and improve the spectral resolution, we demonstrate a novel experimental setup that records the relative delay of the two pulses through optical interference. Moreover, we have demonstrated that this broadband approach can be extended to Fourier transform holographic imaging, which avoids extensive phase retrieval computations. Applications include imaging of biological materials near the carbon K-edge.

Optimized Harmonic Stepped-Waveform for Multilevel Inverter

Sirisukprasert, Siriroj 09 November 1999 (has links)
The concept of multilevel voltage source inverters and their modulation topologies are described. The concept of the Optimized Harmonic Stepped-Waveform (OHSW) technique for a multilevel inverter is presented. By applying this concept, specific harmonics can be eliminated, and the output voltage THD can be improved. A procedure to achieve the appropriate switching angles of the OHSW is proposed. Experimental results are presented to verify the concept. The proposed OHSW technique is implemented on a multilevel inverter using cascaded-inverter with separated dc sources. Comparison between the Selective Harmonic Eliminated PWM and the OHSW is also presented. / Master of Science

A spherical harmonic analysis of the global 1000 mb surface for September 1957.

Padro, Jacob January 1966 (has links)
No description available.

Harmonic representation applied to large scale atmospheric dynamics.

Merilees, P. E. January 1966 (has links)
No description available.

Page generated in 0.0514 seconds