70,942 research outputs found

    Algorithms Implemented for Cancer Gene Searching and Classifications

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    Understanding the gene expression is an important factor to cancer diagnosis. One target of this understanding is implementing cancer gene search and classification methods. However, cancer gene search and classification is a challenge in that there is no an obvious exact algorithm that can be implemented individually for various cancer cells. In this paper a research is con-ducted through the most common top ranked algorithms implemented for cancer gene search and classification, and how they are implemented to reach a better performance. The paper will distinguish algorithms implemented for Bio image analysis for cancer cells and algorithms implemented based on DNA array data. The main purpose of this paper is to explore a road map towards presenting the most current algorithms implemented for cancer gene search and classification

    Objective Identification of Informative Wavelength Regions in Galaxy Spectra

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    Understanding the diversity in spectra is the key to determining the physical parameters of galaxies. The optical spectra of galaxies are highly convoluted with continuum and lines which are potentially sensitive to different physical parameters. Defining the wavelength regions of interest is therefore an important question. In this work, we identify informative wavelength regions in a single-burst stellar populations model by using the CUR Matrix Decomposition. Simulating the Lick/IDS spectrograph configuration, we recover the widely used Dn(4000), Hbeta, and HdeltaA to be most informative. Simulating the SDSS spectrograph configuration with a wavelength range 3450-8350 Angstrom and a model-limited spectral resolution of 3 Angstrom, the most informative regions are: first region-the 4000 Angstrom break and the Hdelta line; second region-the Fe-like indices; third region-the Hbeta line; fourth region-the G band and the Hgamma line. A Principal Component Analysis on the first region shows that the first eigenspectrum tells primarily the stellar age, the second eigenspectrum is related to the age-metallicity degeneracy, and the third eigenspectrum shows an anti-correlation between the strengths of the Balmer and the Ca K and H absorptions. The regions can be used to determine the stellar age and metallicity in early-type galaxies which have solar abundance ratios, no dust, and a single-burst star formation history. The region identification method can be applied to any set of spectra of the user's interest, so that we eliminate the need for a common, fixed-resolution index system. We discuss future directions in extending the current analysis to late-type galaxies.Comment: 36 Pages, 13 Figures, 4 Tables. AJ Accepte
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