5,118 research outputs found
Greedy Search for Descriptive Spatial Face Features
Facial expression recognition methods use a combination of geometric and
appearance-based features. Spatial features are derived from displacements of
facial landmarks, and carry geometric information. These features are either
selected based on prior knowledge, or dimension-reduced from a large pool. In
this study, we produce a large number of potential spatial features using two
combinations of facial landmarks. Among these, we search for a descriptive
subset of features using sequential forward selection. The chosen feature
subset is used to classify facial expressions in the extended Cohn-Kanade
dataset (CK+), and delivered 88.7% recognition accuracy without using any
appearance-based features.Comment: International Conference on Acoustics, Speech and Signal Processing
(ICASSP), 201
Quootstrap: Scalable Unsupervised Extraction of Quotation-Speaker Pairs from Large News Corpora via Bootstrapping
We propose Quootstrap, a method for extracting quotations, as well as the
names of the speakers who uttered them, from large news corpora. Whereas prior
work has addressed this problem primarily with supervised machine learning, our
approach follows a fully unsupervised bootstrapping paradigm. It leverages the
redundancy present in large news corpora, more precisely, the fact that the
same quotation often appears across multiple news articles in slightly
different contexts. Starting from a few seed patterns, such as ["Q", said S.],
our method extracts a set of quotation-speaker pairs (Q, S), which are in turn
used for discovering new patterns expressing the same quotations; the process
is then repeated with the larger pattern set. Our algorithm is highly scalable,
which we demonstrate by running it on the large ICWSM 2011 Spinn3r corpus.
Validating our results against a crowdsourced ground truth, we obtain 90%
precision at 40% recall using a single seed pattern, with significantly higher
recall values for more frequently reported (and thus likely more interesting)
quotations. Finally, we showcase the usefulness of our algorithm's output for
computational social science by analyzing the sentiment expressed in our
extracted quotations.Comment: Accepted at the 12th International Conference on Web and Social Media
(ICWSM), 201
The TRECVID 2007 BBC rushes summarization evaluation pilot
This paper provides an overview of a pilot evaluation of
video summaries using rushes from several BBC dramatic series. It was carried out under the auspices of TRECVID.
Twenty-two research teams submitted video summaries of
up to 4% duration, of 42 individual rushes video files aimed
at compressing out redundant and insignificant material.
The output of two baseline systems built on straightforward
content reduction techniques was contributed by Carnegie
Mellon University as a control. Procedures for developing
ground truth lists of important segments from each video
were developed at Dublin City University and applied to
the BBC video. At NIST each summary was judged by
three humans with respect to how much of the ground truth
was included, how easy the summary was to understand,
and how much repeated material the summary contained.
Additional objective measures included: how long it took
the system to create the summary, how long it took the assessor to judge it against the ground truth, and what the
summary's duration was. Assessor agreement on finding desired segments averaged 78% and results indicate that while it is difficult to exceed the performance of baselines, a few systems did
Multimodal Polynomial Fusion for Detecting Driver Distraction
Distracted driving is deadly, claiming 3,477 lives in the U.S. in 2015 alone.
Although there has been a considerable amount of research on modeling the
distracted behavior of drivers under various conditions, accurate automatic
detection using multiple modalities and especially the contribution of using
the speech modality to improve accuracy has received little attention. This
paper introduces a new multimodal dataset for distracted driving behavior and
discusses automatic distraction detection using features from three modalities:
facial expression, speech and car signals. Detailed multimodal feature analysis
shows that adding more modalities monotonically increases the predictive
accuracy of the model. Finally, a simple and effective multimodal fusion
technique using a polynomial fusion layer shows superior distraction detection
results compared to the baseline SVM and neural network models.Comment: INTERSPEECH 201
Sparsity in Dynamics of Spontaneous Subtle Emotions: Analysis \& Application
Spontaneous subtle emotions are expressed through micro-expressions, which
are tiny, sudden and short-lived dynamics of facial muscles; thus poses a great
challenge for visual recognition. The abrupt but significant dynamics for the
recognition task are temporally sparse while the rest, irrelevant dynamics, are
temporally redundant. In this work, we analyze and enforce sparsity constrains
to learn significant temporal and spectral structures while eliminate
irrelevant facial dynamics of micro-expressions, which would ease the challenge
in the visual recognition of spontaneous subtle emotions. The hypothesis is
confirmed through experimental results of automatic spontaneous subtle emotion
recognition with several sparsity levels on CASME II and SMIC, the only two
publicly available spontaneous subtle emotion databases. The overall
performances of the automatic subtle emotion recognition are boosted when only
significant dynamics are preserved from the original sequences.Comment: IEEE Transaction of Affective Computing (2016
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Artificial Immune Systems - Models, algorithms and applications
Copyright © 2010 Academic Research Publishing Agency.This article has been made available through the Brunel Open Access Publishing Fund.Artificial Immune Systems (AIS) are computational paradigms that belong to the computational intelligence family and are inspired by the biological immune system. During the past decade, they have attracted a lot of interest from researchers aiming to develop immune-based models and techniques to solve complex computational or engineering problems. This work presents a survey of existing AIS models and algorithms with a focus on the last five years.This article is available through the Brunel Open Access Publishing Fun
Acoustic data optimisation for seabed mapping with visual and computational data mining
Oceans cover 70% of Earth’s surface but little is known about their waters.
While the echosounders, often used for exploration of our oceans, have developed at
a tremendous rate since the WWII, the methods used to analyse and interpret the data
still remain the same. These methods are inefficient, time consuming, and often
costly in dealing with the large data that modern echosounders produce. This PhD
project will examine the complexity of the de facto seabed mapping technique by
exploring and analysing acoustic data with a combination of data mining and visual
analytic methods.
First we test the redundancy issues in multibeam echosounder (MBES) data
by using the component plane visualisation of a Self Organising Map (SOM). A total
of 16 visual groups were identified among the 132 statistical data descriptors. The
optimised MBES dataset had 35 attributes from 16 visual groups and represented a
73% reduction in data dimensionality. A combined Principal Component Analysis
(PCA) + k-means was used to cluster both the datasets. The cluster results were
visually compared as well as internally validated using four different internal
validation methods.
Next we tested two novel approaches in singlebeam echosounder (SBES)
data processing and clustering – using visual exploration for outlier detection and
direct clustering of time series echo returns. Visual exploration identified further
outliers the automatic procedure was not able to find. The SBES data were then
clustered directly. The internal validation indices suggested the optimal number of
clusters to be three. This is consistent with the assumption that the SBES time series
represented the subsurface classes of the seabed.
Next the SBES data were joined with the corresponding MBES data based on
identification of the closest locations between MBES and SBES. Two algorithms,
PCA + k-means and fuzzy c-means were tested and results visualised. From visual
comparison, the cluster boundary appeared to have better definitions when compared
to the clustered MBES data only. The results seem to indicate that adding SBES did
in fact improve the boundary definitions.
Next the cluster results from the analysis chapters were validated against
ground truth data using a confusion matrix and kappa coefficients. For MBES, the
classes derived from optimised data yielded better accuracy compared to that of the
original data. For SBES, direct clustering was able to provide a relatively reliable
overview of the underlying classes in survey area. The combined MBES + SBES
data provided by far the best accuracy for mapping with almost a 10% increase in
overall accuracy compared to that of the original MBES data.
The results proved to be promising in optimising the acoustic data and
improving the quality of seabed mapping. Furthermore, these approaches have the
potential of significant time and cost saving in the seabed mapping process. Finally
some future directions are recommended for the findings of this research project with
the consideration that this could contribute to further development of seabed
mapping problems at mapping agencies worldwide
Spontaneous Subtle Expression Detection and Recognition based on Facial Strain
Optical strain is an extension of optical flow that is capable of quantifying
subtle changes on faces and representing the minute facial motion intensities
at the pixel level. This is computationally essential for the relatively new
field of spontaneous micro-expression, where subtle expressions can be
technically challenging to pinpoint. In this paper, we present a novel method
for detecting and recognizing micro-expressions by utilizing facial optical
strain magnitudes to construct optical strain features and optical strain
weighted features. The two sets of features are then concatenated to form the
resultant feature histogram. Experiments were performed on the CASME II and
SMIC databases. We demonstrate on both databases, the usefulness of optical
strain information and more importantly, that our best approaches are able to
outperform the original baseline results for both detection and recognition
tasks. A comparison of the proposed method with other existing spatio-temporal
feature extraction approaches is also presented.Comment: 21 pages (including references), single column format, accepted to
Signal Processing: Image Communication journa
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