Symmetry-enhanced spectral analysis via the spectral method and filter diagonalization

1998 ◽  
Vol 57 (6) ◽  
pp. 7288-7293 ◽  
Author(s):  
Rongqing Chen ◽  
Hua Guo
Keyword(s):  
Spectral Analysis ◽  
Spectral Method ◽  
Filter Diagonalization

scholarly journals ESTIMASI KETEBALAN SEDIMEN DENGAN ANALISIS POWER SPECTRAL PADA DATA ANOMALI GAYABERAT

GEOMATIKA ◽  
2018 ◽  
Vol 23 (2) ◽  
pp. 65 ◽  
Author(s):  
Mila Apriani ◽  
Admiral Musa Julius ◽  
Mahmud Yusuf ◽  
Damianus Tri Heryanto ◽  
Agus Marsono
Keyword(s):  
Spectral Analysis ◽  
Fourier Transform ◽  
Gravity Anomaly ◽  
Spectral Method ◽  
Gravity Data ◽  
Sediment Thickness ◽  
Transform Method ◽  
Fourier Transform Method ◽  
Power Spectral ◽  
The Fourier Transform

<p align="center"><strong>ABSTRAK</strong></p><p> </p><p>Penelitian dengan analisis <em>power spectral</em> data anomali gayaberat telah banyak dilakukan untuk estimasi ketebalan sedimen. Dalam studi ini penulis melakukan analisis spektral data anomali gayaberat wilayah DKI Jakarta untuk mengetahui kedalaman sumber anomali yang bersesuaian dengan ketebalan sedimen. Data yang digunakan berupa data gayaberat dari BMKG tahun 2014 dengan 197 lokasi titik pengukuran yang tersebar di koordinat 6,08º-6,36º LU dan 106,68º-106,97º BT. Studi ini menggunakan metode <em>power spectral</em>  dengan mentransformasikan data dari domain jarak ke dalam domain bilangan gelombang memanfaatkan transformasi <em>Fourier</em>. Hasil penelitian dengan menggunakan metode transformasi <em>Fourier  </em>menunjukkan bahwa ketebalan sedimen di Jakarta dari arah selatan ke utara semakin besar, di sekitar Babakan ketebalan diperkirakan 92 meter, sekitar Tongkol, Jakarta Utara diperkirakan 331 meter.</p><p><strong> </strong></p><p><strong>Kata kunci</strong>: <em>power spectral</em>, anomali gayaberat, ketebalan sedimen</p><p align="center"><strong><em> </em></strong></p><p align="center"><strong><em>ABSTRACT</em></strong></p><p><em> </em></p><p><em>Studies of spectral analysis of gravity anomaly data have been carried out to estimate the thickness of sediment. In this study the author did spectral analysis of gravity anomaly data of DKI Jakarta area to know the depth of anomaly source which corresponds to the thickness of sediment. The data used in the form of gravity data from BMKG 2014 with 197 locations of measurement points spread in coordinates 6.08º - 6.36º N and 106.68º - 106.97º E. This study used the power spectral method by transforming the data from the distance domain into the wavenumber domain utilizing the Fourier transform. The result of the research using Fourier transform method shows that the thickness of sediment in Jakarta from south to north is getting bigger, in Babakan the thickness of the sediment is around 92 meter, in Tongkol, North Jakarta is around 331 meter.</em></p><p><strong><em> </em></strong></p><p><strong><em>Keywords</em></strong><em>: </em><em>power spectral, gravity anomaly, sediment thickness</em><em></em></p>

SEMI-CLASSICAL PROPAGATION AND SPECTRAL ANALYSIS IN THE H- ION INTERACTING WITH A METALLIC SURFACE

2005 ◽  
Vol 04 (02) ◽  
pp. 357-372
Author(s):  
JOHN JAIRO ZULUAGA ◽  
JORGE MAHECHA ◽  
EUGENE CHULKOV
Keyword(s):  
Spectral Analysis ◽  
Local Potential ◽  
Metallic Surface ◽  
Electron Interaction ◽  
Time Signal ◽  
Filter Diagonalization ◽  
Resonant States ◽  
Classical Trajectories ◽  
Short Time ◽  
Harmonic Inversion

A semi-classical propagator method combined with harmonic inversion of short time signals is used to find the resonant states of an electron interacting with a hydrogen atom near a metallic surface. The atom-electron interaction corresponds to one electron in the presence of a neutral compact core, which can be described by a simple local potential proposed by Cohen. On the other hand, the electron-surface interaction is described by a model proposed by Jennings, the so-called Jelly Model, or by a more realistic local potential that takes into account the shell structure of the metal. A semi-classical propagator approach, proposed by Herman and Kluk, is used to calculate an approximation to the autocorrelation function A(t) = <ψt|ψ0> entirely in terms of classical trajectories. A filter-diagonalization method for harmonic inversion of the complex time signal A(t) is applied to extract the resonances. We verified that the spectral analysis of the signal obtained by semi-classical methods gives satisfactory numerical results for the position and width of the lowest lying resonances.

An Assessment of Linear Spectral Analysis Method for Offshore Structures via Random Sea Simulation

1982 ◽  
Vol 104 (1) ◽  
pp. 39-46 ◽  
Author(s):  
S. Kao
Keyword(s):  
Spectral Analysis ◽  
Spectral Method ◽  
Drag Force ◽  
Flexible Structures ◽  
Offshore Structures ◽  
Analysis Method ◽  
Corrective Measures ◽  
Spectral Analysis Method

With random sea simulation, application of linear spectral analysis method to offshore structures with moderate drag force has been assessed. Findings indicate overprediction of response for short natural periods and underprediction for very long periods. Tentative corrective measures are recommended. Significant force and response reductions have been calculated for flexible structures which are not adequately predicted by the linear spectral method.

Reproducibility of three different methods of measuring baroreflex sensitivity in normal subjects

1998 ◽  
Vol 95 (5) ◽  
pp. 575-581 ◽  
Author(s):  
S. W. LORD ◽  
R. H. CLAYTON ◽  
M. C. S. HALL ◽  
J. C. GRAY ◽  
A. MURRAY ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Spectral Method ◽  
Coefficient Of Variation ◽  
Baroreflex Sensitivity ◽  
Low Frequency ◽  
Frequency Component ◽  
Non Invasive ◽  
Invasive Method ◽  
Head Up Tilt ◽  
Invasive Measurement

1.Baroreflex sensitivity is a useful tool for investigating cardiovascular reflexes in a number of clinical settings. Several different methods of measuring baroreflex sensitivity are available. In order to determine a clinically useful non-invasive method of measuring baroreflex sensitivity we compared two methods (spectral analysis and the Valsalva manoeuvre) with regard to reproducibility, agreement with a standard invasive method (phenylephrine infusion) and failure rate. 2.Twenty-six healthy subjects aged 22 to 63 years attended on three separate occasions for measurement of baroreflex sensitivity using the different methods. The effect of a recent head-up tilt on baroreflex sensitivity was measured. 3.Reproducibility was best for the low-frequency component of the spectral method [coefficient of variation 25.0% (range 3.5–42.4%)] and worst for the Valsalva method [coefficient of variation 29.3% (range 13.8–93.1%)]. Both non-invasive methods overestimated values compared with the phenylephrine method [bias of low-frequency component of the spectral method, 1.17 (0.38–3.6); bias of the Valsalva method, 1.13 (0.19–6.7)]. The high-frequency component of the spectral method did not agree with the phenylephrine method. 4.The spectral analysis method had the fewest failures (seven subjects with a failure on at least one occasion), and the phenylephrine method the most (16 subjects with a failure on at least one occasion). A short head-up tilt did not affect the subsequent non-invasive measurement of baroreflex sensitivity. 5.It was concluded that the low-frequency component of the spectral method was the most clinically useful non-invasive measurement of baroreflex sensitivity.

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