70,942 research outputs found
Algorithms Implemented for Cancer Gene Searching and Classifications
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
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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Statistical Semantic Classification of Crisis Information
The rise of social media as an information channel during crisis has become key to community response. However, existing crisis awareness applications, often struggle to identify relevant information among the high volume of data that is generated over social platforms. A wide range of statistical features and machine learning methods have been researched in recent years to automatically classify this information. In this paper we aim to complement previous studies by exploring the use of semantics as additional features to identify relevant crisis in- formation. Our assumption is that entities and concepts tend to have a more consistent correlation with relevant and irrelevant information, and therefore can enhance the discrimination power of classifiers. Our results, so far, show that some classification improvements can be obtained when using semantic features, reaching +2.51% when the classifier is applied to a new crisis event (i.e., not in training set)
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