28,498 research outputs found
Communication Theoretic Data Analytics
Widespread use of the Internet and social networks invokes the generation of
big data, which is proving to be useful in a number of applications. To deal
with explosively growing amounts of data, data analytics has emerged as a
critical technology related to computing, signal processing, and information
networking. In this paper, a formalism is considered in which data is modeled
as a generalized social network and communication theory and information theory
are thereby extended to data analytics. First, the creation of an equalizer to
optimize information transfer between two data variables is considered, and
financial data is used to demonstrate the advantages. Then, an information
coupling approach based on information geometry is applied for dimensionality
reduction, with a pattern recognition example to illustrate the effectiveness.
These initial trials suggest the potential of communication theoretic data
analytics for a wide range of applications.Comment: Published in IEEE Journal on Selected Areas in Communications, Jan.
201
Interest rates mapping
The present study deals with the analysis and mapping of Swiss franc interest
rates. Interest rates depend on time and maturity, defining term structure of
the interest rate curves (IRC). In the present study IRC are considered in a
two-dimensional feature space - time and maturity. Geostatistical models and
machine learning algorithms (multilayer perceptron and Support Vector Machines)
were applied to produce interest rate maps. IR maps can be used for the
visualisation and patterns perception purposes, to develop and to explore
economical hypotheses, to produce dynamic asses-liability simulations and for
the financial risk assessments. The feasibility of an application of interest
rates mapping approach for the IRC forecasting is considered as well.Comment: 8 pages, 8 figures. Presented at Applications of Physics in Financial
Analysis conference (APFA6), Lisbon, Portugal, 200
Weighted Contrastive Divergence
Learning algorithms for energy based Boltzmann architectures that rely on
gradient descent are in general computationally prohibitive, typically due to
the exponential number of terms involved in computing the partition function.
In this way one has to resort to approximation schemes for the evaluation of
the gradient. This is the case of Restricted Boltzmann Machines (RBM) and its
learning algorithm Contrastive Divergence (CD). It is well-known that CD has a
number of shortcomings, and its approximation to the gradient has several
drawbacks. Overcoming these defects has been the basis of much research and new
algorithms have been devised, such as persistent CD. In this manuscript we
propose a new algorithm that we call Weighted CD (WCD), built from small
modifications of the negative phase in standard CD. However small these
modifications may be, experimental work reported in this paper suggest that WCD
provides a significant improvement over standard CD and persistent CD at a
small additional computational cost
Continuous Action Recognition Based on Sequence Alignment
Continuous action recognition is more challenging than isolated recognition
because classification and segmentation must be simultaneously carried out. We
build on the well known dynamic time warping (DTW) framework and devise a novel
visual alignment technique, namely dynamic frame warping (DFW), which performs
isolated recognition based on per-frame representation of videos, and on
aligning a test sequence with a model sequence. Moreover, we propose two
extensions which enable to perform recognition concomitant with segmentation,
namely one-pass DFW and two-pass DFW. These two methods have their roots in the
domain of continuous recognition of speech and, to the best of our knowledge,
their extension to continuous visual action recognition has been overlooked. We
test and illustrate the proposed techniques with a recently released dataset
(RAVEL) and with two public-domain datasets widely used in action recognition
(Hollywood-1 and Hollywood-2). We also compare the performances of the proposed
isolated and continuous recognition algorithms with several recently published
methods
A Deep Dive into Understanding Tumor Foci Classification using Multiparametric MRI Based on Convolutional Neural Network
Deep learning models have had a great success in disease classifications
using large data pools of skin cancer images or lung X-rays. However, data
scarcity has been the roadblock of applying deep learning models directly on
prostate multiparametric MRI (mpMRI). Although model interpretation has been
heavily studied for natural images for the past few years, there has been a
lack of interpretation of deep learning models trained on medical images. This
work designs a customized workflow for the small and imbalanced data set of
prostate mpMRI where features were extracted from a deep learning model and
then analyzed by a traditional machine learning classifier. In addition, this
work contributes to revealing how deep learning models interpret mpMRI for
prostate cancer patients stratification
- …