9,009 research outputs found
A Taxonomy of Big Data for Optimal Predictive Machine Learning and Data Mining
Big data comes in various ways, types, shapes, forms and sizes. Indeed,
almost all areas of science, technology, medicine, public health, economics,
business, linguistics and social science are bombarded by ever increasing flows
of data begging to analyzed efficiently and effectively. In this paper, we
propose a rough idea of a possible taxonomy of big data, along with some of the
most commonly used tools for handling each particular category of bigness. The
dimensionality p of the input space and the sample size n are usually the main
ingredients in the characterization of data bigness. The specific statistical
machine learning technique used to handle a particular big data set will depend
on which category it falls in within the bigness taxonomy. Large p small n data
sets for instance require a different set of tools from the large n small p
variety. Among other tools, we discuss Preprocessing, Standardization,
Imputation, Projection, Regularization, Penalization, Compression, Reduction,
Selection, Kernelization, Hybridization, Parallelization, Aggregation,
Randomization, Replication, Sequentialization. Indeed, it is important to
emphasize right away that the so-called no free lunch theorem applies here, in
the sense that there is no universally superior method that outperforms all
other methods on all categories of bigness. It is also important to stress the
fact that simplicity in the sense of Ockham's razor non plurality principle of
parsimony tends to reign supreme when it comes to massive data. We conclude
with a comparison of the predictive performance of some of the most commonly
used methods on a few data sets.Comment: 18 pages, 2 figures 3 table
Taming Wild High Dimensional Text Data with a Fuzzy Lash
The bag of words (BOW) represents a corpus in a matrix whose elements are the
frequency of words. However, each row in the matrix is a very high-dimensional
sparse vector. Dimension reduction (DR) is a popular method to address sparsity
and high-dimensionality issues. Among different strategies to develop DR
method, Unsupervised Feature Transformation (UFT) is a popular strategy to map
all words on a new basis to represent BOW. The recent increase of text data and
its challenges imply that DR area still needs new perspectives. Although a wide
range of methods based on the UFT strategy has been developed, the fuzzy
approach has not been considered for DR based on this strategy. This research
investigates the application of fuzzy clustering as a DR method based on the
UFT strategy to collapse BOW matrix to provide a lower-dimensional
representation of documents instead of the words in a corpus. The quantitative
evaluation shows that fuzzy clustering produces superior performance and
features to Principal Components Analysis (PCA) and Singular Value
Decomposition (SVD), two popular DR methods based on the UFT strategy
Dimension Reduction by Mutual Information Discriminant Analysis
In the past few decades, researchers have proposed many discriminant analysis
(DA) algorithms for the study of high-dimensional data in a variety of
problems. Most DA algorithms for feature extraction are based on
transformations that simultaneously maximize the between-class scatter and
minimize the withinclass scatter matrices. This paper presents a novel DA
algorithm for feature extraction using mutual information (MI). However, it is
not always easy to obtain an accurate estimation for high-dimensional MI. In
this paper, we propose an efficient method for feature extraction that is based
on one-dimensional MI estimations. We will refer to this algorithm as mutual
information discriminant analysis (MIDA). The performance of this proposed
method was evaluated using UCI databases. The results indicate that MIDA
provides robust performance over different data sets with different
characteristics and that MIDA always performs better than, or at least
comparable to, the best performing algorithms.Comment: 13pages, 3 tables, International Journal of Artificial Intelligence &
Application
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