13,213 research outputs found
A Survey on Soft Subspace Clustering
Subspace clustering (SC) is a promising clustering technology to identify
clusters based on their associations with subspaces in high dimensional spaces.
SC can be classified into hard subspace clustering (HSC) and soft subspace
clustering (SSC). While HSC algorithms have been extensively studied and well
accepted by the scientific community, SSC algorithms are relatively new but
gaining more attention in recent years due to better adaptability. In the
paper, a comprehensive survey on existing SSC algorithms and the recent
development are presented. The SSC algorithms are classified systematically
into three main categories, namely, conventional SSC (CSSC), independent SSC
(ISSC) and extended SSC (XSSC). The characteristics of these algorithms are
highlighted and the potential future development of SSC is also discussed.Comment: This paper has been published in Information Sciences Journal in 201
Phenotypic landscape inference reveals multiple evolutionary paths to C photosynthesis
C photosynthesis has independently evolved from the ancestral C
pathway in at least 60 plant lineages, but, as with other complex traits, how
it evolved is unclear. Here we show that the polyphyletic appearance of C
photosynthesis is associated with diverse and flexible evolutionary paths that
group into four major trajectories. We conducted a meta-analysis of 18 lineages
containing species that use C, C, or intermediate C-C forms of
photosynthesis to parameterise a 16-dimensional phenotypic landscape. We then
developed and experimentally verified a novel Bayesian approach based on a
hidden Markov model that predicts how the C phenotype evolved. The
alternative evolutionary histories underlying the appearance of C
photosynthesis were determined by ancestral lineage and initial phenotypic
alterations unrelated to photosynthesis. We conclude that the order of C
trait acquisition is flexible and driven by non-photosynthetic drivers. This
flexibility will have facilitated the convergent evolution of this complex
trait
Multivariate Approaches to Classification in Extragalactic Astronomy
Clustering objects into synthetic groups is a natural activity of any
science. Astrophysics is not an exception and is now facing a deluge of data.
For galaxies, the one-century old Hubble classification and the Hubble tuning
fork are still largely in use, together with numerous mono-or bivariate
classifications most often made by eye. However, a classification must be
driven by the data, and sophisticated multivariate statistical tools are used
more and more often. In this paper we review these different approaches in
order to situate them in the general context of unsupervised and supervised
learning. We insist on the astrophysical outcomes of these studies to show that
multivariate analyses provide an obvious path toward a renewal of our
classification of galaxies and are invaluable tools to investigate the physics
and evolution of galaxies.Comment: Open Access paper.
http://www.frontiersin.org/milky\_way\_and\_galaxies/10.3389/fspas.2015.00003/abstract\>.
\<10.3389/fspas.2015.00003 \&g
Design of Easily Synchronizable Oscillator Networks Using the Monte Carlo Optimization Method
Starting with an initial random network of oscillators with a heterogeneous
frequency distribution, its autonomous synchronization ability can be largely
improved by appropriately rewiring the links between the elements. Ensembles of
synchronization-optimized networks with different connectivities are generated
and their statistical properties are studied
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