10,499 research outputs found
Role of sentiment classification in sentiment analysis: a survey
Through a survey of literature, the role of sentiment classification in sentiment analysis has been reviewed. The review identifies the research challenges involved in tackling sentiment classification. A total of 68 articles during 2015 – 2017 have been reviewed on six dimensions viz., sentiment classification, feature extraction, cross-lingual sentiment classification, cross-domain sentiment classification, lexica and corpora creation and multi-label sentiment classification. This study discusses the prominence and effects of sentiment classification in sentiment evaluation and a lot of further research needs to be done for productive results
Self-tuned Visual Subclass Learning with Shared Samples An Incremental Approach
Computer vision tasks are traditionally defined and evaluated using semantic
categories. However, it is known to the field that semantic classes do not
necessarily correspond to a unique visual class (e.g. inside and outside of a
car). Furthermore, many of the feasible learning techniques at hand cannot
model a visual class which appears consistent to the human eye. These problems
have motivated the use of 1) Unsupervised or supervised clustering as a
preprocessing step to identify the visual subclasses to be used in a
mixture-of-experts learning regime. 2) Felzenszwalb et al. part model and other
works model mixture assignment with latent variables which is optimized during
learning 3) Highly non-linear classifiers which are inherently capable of
modelling multi-modal input space but are inefficient at the test time. In this
work, we promote an incremental view over the recognition of semantic classes
with varied appearances. We propose an optimization technique which
incrementally finds maximal visual subclasses in a regularized risk
minimization framework. Our proposed approach unifies the clustering and
classification steps in a single algorithm. The importance of this approach is
its compliance with the classification via the fact that it does not need to
know about the number of clusters, the representation and similarity measures
used in pre-processing clustering methods a priori. Following this approach we
show both qualitatively and quantitatively significant results. We show that
the visual subclasses demonstrate a long tail distribution. Finally, we show
that state of the art object detection methods (e.g. DPM) are unable to use the
tails of this distribution comprising 50\% of the training samples. In fact we
show that DPM performance slightly increases on average by the removal of this
half of the data.Comment: Updated ICCV 2013 submissio
Spacetime Reduction of Large N Flavor Models: A Fundamental Theory of Emergent Local Geometry?
We introduce a novel spacetime reduction procedure for the fields of a
supergravity-Yang-Mills theory in generic curved spacetime background, and with
large N flavor group, to linearized forms on an infinitesimal patch of local
tangent space at a point in the spacetime manifold. Our new prescription for
spacetime reduction preserves all of the local symmetries of the continuum
field theory Lagrangian in the resulting zero-dimensional matrix Lagrangian,
thereby obviating difficulties encountered in previous matrix proposals for
emergent spacetime in recovering the full nonlinear symmetries of Einstein
gravity. We conjecture that the zero-dimensional matrix model obtained by this
prescription for spacetime reduction of the circle-compactified type
I-I'-mIIA-IIB-heterotic supergravity-Yang-Mills theory with sixteen
supercharges and large N flavor group, and inclusive of the full spectrum of
Dpbrane charges, offers a potentially complete framework for nonperturbative
string/M theory. We explain the relationship of our conjecture for a
fundamental theory of emergent local spacetime geometry to recent
investigations of the hidden symmetry algebra of M theory, stressing insights
that are to be gained from the algebraic perspective. We conclude with a list
of open questions and directions for future work.Comment: 30pgs. v6: Ref [4] added, some terminology corrected in Intro,
sections 5,6. Footnote 2 clarifies the relation to hep-th/0201129v1.
Acknowledgments adde
Detecting event-related recurrences by symbolic analysis: Applications to human language processing
Quasistationarity is ubiquitous in complex dynamical systems. In brain
dynamics there is ample evidence that event-related potentials reflect such
quasistationary states. In order to detect them from time series, several
segmentation techniques have been proposed. In this study we elaborate a recent
approach for detecting quasistationary states as recurrence domains by means of
recurrence analysis and subsequent symbolisation methods. As a result,
recurrence domains are obtained as partition cells that can be further aligned
and unified for different realisations. We address two pertinent problems of
contemporary recurrence analysis and present possible solutions for them.Comment: 24 pages, 6 figures. Draft version to appear in Proc Royal Soc
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