Results 81 to 90 of about 152,938 (206)
, 2011 The classification of hyperspectral images on heterogeneous environments without prior knowledge about the study area is a challenging task. Finding potential pure spectral signatures or endmembers (EM) of the various surface materials within an image is
Mende, Andre +4 more
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Redshift dependence of QSO spectral variability
, 2006 We present a combined analysis of the optical spectral variability for two samples of QSOs, 42 objects at z < 0.4 monitored at the Wise Observatory, plus 59 objects up to z approximate to 3 in the field of the Magellanic Clouds, detected and/or monitored
Vagnetti, F +5 more
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Application of hos for heart rate variability
, 2022 This work is devoted to calculation of higher order spectra (HOS) of ECG signals and comparing of results of standard spectral and statistical methods and HOS methods for heart rate variability (HRV) analysis.
Zhemchuzhkina, T. V., Abdallah, Iren
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Spectral variability in NGC 1042 ULX1
, 2022 We report X-ray spectral variability in an ultraluminous X-ray source NGC 1042 ULX1, using archival XMM-Newton and recent NuSTAR observations. In long-term evolution, the source has shown a trend of variation in spectral hardness.
Ghosh, Tanuman, Rana, Vikram
core +1 more source
A New Extended Linear Mixing Model to Address Spectral Variability
, 2014 International audienceSpectral variability is a phenomenon due, to a grand extend, to variations in the illumination and atmospheric conditions within a hyperspectral image, causing the spectral signature of a material to vary within a image.
Drumetz, Lucas +13 more
core +1 more source
Quasar spectral variability from the XMM-Newton serendipitous source catalogue [PDF]
, 2016 Context. X-ray spectral variability analyses of active galactic nuclei (AGN) with moderate luminosities and redshifts typically show a softer when brighter behaviour.
R. Middei +15 more
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Tropical ocean-atmosphere controls on inter-annual climate variability in the Cretaceous Arctic
, 2011 The first annually resolved sedimentary record from the Cretaceous is used to develop time series of inter-annual and decadal scale climate variability from the Arctic Ocean.
Kemp, Alan E.S. +5 more
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A Measure of Variability in Comovement for Economic Variables : a Time-Varying Coherence Function Approach [PDF]
In this paper, we test the instability of comovement, in time and frequency domain, for the GDP growth rate of the US and the UK. We use the frequency approach, which is based on evolutionary spectral analysis (Priestley, 1965-1996).
Mohamed Boutahar, Essahbi Essaadi
core +2 more sources
A toy model for the X-ray spectral variability of active galactic nuclei
, 2014 Investigations into the long-term X-ray spectral variability of 10 active galactic nuclei (AGNs) revealed a positive spectral index-flux correlation for each object.
Cao, Xinwu, Wang, Jun-Xian
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LiDAR-GUIDED REDUCTION OF SPECTRAL VARIABILITY IN HYPERSPECTRAL IMAGERY
, 2019 Hyperspectral unmixing has attained a great importance in recent decades in remote sensing applications. Due to some external effect (illumination conditions) or internal effects (concentration of chlorophyll), spectral variability exists in ...
Bacher, Raphael +4 more
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