6,945 research outputs found
Palmprint image registration using convolutional neural networks and Hough transform
Minutia-based palmprint recognition systems has got lots of interest in last
two decades. Due to the large number of minutiae in a palmprint, approximately
1000 minutiae, the matching process is time consuming which makes it
unpractical for real time applications. One way to address this issue is
aligning all palmprint images to a reference image and bringing them to a same
coordinate system. Bringing all palmprint images to a same coordinate system,
results in fewer computations during minutia matching. In this paper, using
convolutional neural network (CNN) and generalized Hough transform (GHT), we
propose a new method to register palmprint images accurately. This method,
finds the corresponding rotation and displacement (in both x and y direction)
between the palmprint and a reference image. Exact palmprint registration can
enhance the speed and the accuracy of matching process. Proposed method is
capable of distinguishing between left and right palmprint automatically which
helps to speed up the matching process. Furthermore, designed structure of CNN
in registration stage, gives us the segmented palmprint image from background
which is a pre-processing step for minutia extraction. The proposed
registration method followed by minutia-cylinder code (MCC) matching algorithm
has been evaluated on the THUPALMLAB database, and the results show the
superiority of our algorithm over most of the state-of-the-art algorithms.Comment: 6 figures, 8 page
ATD: Anomalous Topic Discovery in High Dimensional Discrete Data
We propose an algorithm for detecting patterns exhibited by anomalous
clusters in high dimensional discrete data. Unlike most anomaly detection (AD)
methods, which detect individual anomalies, our proposed method detects groups
(clusters) of anomalies; i.e. sets of points which collectively exhibit
abnormal patterns. In many applications this can lead to better understanding
of the nature of the atypical behavior and to identifying the sources of the
anomalies. Moreover, we consider the case where the atypical patterns exhibit
on only a small (salient) subset of the very high dimensional feature space.
Individual AD techniques and techniques that detect anomalies using all the
features typically fail to detect such anomalies, but our method can detect
such instances collectively, discover the shared anomalous patterns exhibited
by them, and identify the subsets of salient features. In this paper, we focus
on detecting anomalous topics in a batch of text documents, developing our
algorithm based on topic models. Results of our experiments show that our
method can accurately detect anomalous topics and salient features (words)
under each such topic in a synthetic data set and two real-world text corpora
and achieves better performance compared to both standard group AD and
individual AD techniques. All required code to reproduce our experiments is
available from https://github.com/hsoleimani/AT
Solubility of groups can be characterized by configuration
The concept of configuration was first introduced by Rosenblatt and Willis to
give a characterization for the amenability of groups. We show that group
properties of being soluble or FC can be characterized by configuration sets.
Then we investigate some condition on configuration pairs, which leads to
isomorphism. We introduce a somewhat different notion of configuration
equivalence, namely strong configuration equivalence, and prove that strong
configuration equivalence coincides with isomorphism.Comment: 19 page
Parsimonious Topic Models with Salient Word Discovery
We propose a parsimonious topic model for text corpora. In related models
such as Latent Dirichlet Allocation (LDA), all words are modeled
topic-specifically, even though many words occur with similar frequencies
across different topics. Our modeling determines salient words for each topic,
which have topic-specific probabilities, with the rest explained by a universal
shared model. Further, in LDA all topics are in principle present in every
document. By contrast our model gives sparse topic representation, determining
the (small) subset of relevant topics for each document. We derive a Bayesian
Information Criterion (BIC), balancing model complexity and goodness of fit.
Here, interestingly, we identify an effective sample size and corresponding
penalty specific to each parameter type in our model. We minimize BIC to
jointly determine our entire model -- the topic-specific words,
document-specific topics, all model parameter values, {\it and} the total
number of topics -- in a wholly unsupervised fashion. Results on three text
corpora and an image dataset show that our model achieves higher test set
likelihood and better agreement with ground-truth class labels, compared to LDA
and to a model designed to incorporate sparsity
Configuration Equivalence is not Equivalent to Isomorphism
Giving a condition for the the amenability of groups, Rosenblatt and Willis,
first introduced the concept of configuration. From the beginning of the
theory, the question whether the concept of configuration equivalence coincides
with the concept of group isomorphism was posed. We negatively answer this open
question by introducing two non-isomorphic, solvable and hence amenable groups
which are configuration equivalent. Also, we will study some types of subgroups
in configuration equivalent groups. In particular, we will prove this
conjecture, due to Rosenblatt and Willis, that configuration equivalent groups,
both include the free non-Abelian group of same rank or not. Finally, we prove
that two-sided equivalent groups have same class numbers
A necessary condition for zero divisors in complex group algebra of torsion-free groups
We find a necessary condition for zero divisors in complex group algebras of
torsion-free groups
Gruss type inequalities in semi-inner product C*-modules and applications
Some Gruss type inequalities in semi-inner product modules over C*-algebras
for n-tuples of vectors are established. Also we give their natu- ral
applications for the approximation of the discrete Fourier and the Melin
transforms of bounded linear operators on a Hilbert space.Comment: arXiv admin note: substantial text overlap with arXiv:1409.4990; text
overlap with arXiv:math/0309354 by other author
Reconstruction of the core convex topology and its applications in vector optimization and convex analysis
In this paper, the core convex topology on a real vector space , which is
constructed just by operators, is investigated. This topology, denoted by
, is the strongest topology which makes into a locally convex
space. It is shown that some algebraic notions
existing in the literature come from this topology. In fact, it is proved that
algebraic interior and vectorial closure notions, considered in the literature
as replacements of topological interior and topological closure, respectively,
in vector spaces not necessarily equipped with a topology, are actually nothing
else than the interior and closure with the respect to the core convex
topology. We reconstruct the core convex topology using an appropriate
topological basis which enables us to characterize its open sets.
Furthermore, it is proved that is not metrizable when X is
infinite-dimensional, and also it enjoys the Hine-Borel property. Using these
properties, -compact sets are characterized and a characterization of
finite-dimensionality is provided. Finally, it is shown that the properties of
the core convex topology lead to directly extending various important results
in convex analysis and vector optimization from topological vector spaces to
real vector spaces
Balance between noise fluxes in free-running single-mode class-A lasers
The fluctuation effect of laser pumping rate on the output noise fluxes of
class-A lasers is investigated. The method is based on the role of cavity
Langevin force as a fluctuating force in the absence of the atomic population
inversion and dipole moment Langevin forces. The temporal fluctuations induced
to the phase and amplitude of the cavity electric field and the atomic
population inversion are calculated in both below and above threshold states.
Our aim is to derive correlation functions for the fluctuating variables of the
cavity electric field and the atomic population inversion to determine the
noise fluxes emerging from the cavity mirrors and measured by an optical
detector and those radiated in the form of spontaneous emission in all spatial
directions. We introduce a heuristic conservation relation that connects the
noise flux generated by the laser pumping system with those distributed among
the laser variables. Finally, the results are confirmed by demonstrating the
energy conservation law.Comment: 8 pages, 4 figures; Quantum Electronics, IEEE Journal of, 201
Scalable Joint Models for Reliable Uncertainty-Aware Event Prediction
Missing data and noisy observations pose significant challenges for reliably
predicting events from irregularly sampled multivariate time series
(longitudinal) data. Imputation methods, which are typically used for
completing the data prior to event prediction, lack a principled mechanism to
account for the uncertainty due to missingness. Alternatively, state-of-the-art
joint modeling techniques can be used for jointly modeling the longitudinal and
event data and compute event probabilities conditioned on the longitudinal
observations. These approaches, however, make strong parametric assumptions and
do not easily scale to multivariate signals with many observations. Our
proposed approach consists of several key innovations. First, we develop a
flexible and scalable joint model based upon sparse multiple-output Gaussian
processes. Unlike state-of-the-art joint models, the proposed model can explain
highly challenging structure including non-Gaussian noise while scaling to
large data. Second, we derive an optimal policy for predicting events using the
distribution of the event occurrence estimated by the joint model. The derived
policy trades-off the cost of a delayed detection versus incorrect assessments
and abstains from making decisions when the estimated event probability does
not satisfy the derived confidence criteria. Experiments on a large dataset
show that the proposed framework significantly outperforms state-of-the-art
techniques in event prediction.Comment: To appear in IEEE Transaction on Pattern Analysis and Machine
Intelligenc
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