Table Of ContentSPRINGER BRIEFS IN APPLIED SCIENCES AND
TECHNOLOGY COMPUTATIONAL INTELLIGENCE
Jonathan Amezcua
Patricia Melin
Oscar Castillo
New Classification
Method Based on
Modular Neural
Networks with the
LVQ Algorithm and
Type-2 Fuzzy Logic
SpringerBriefs in Applied Sciences
and Technology
Computational Intelligence
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Janusz Kacprzyk, Polish Academy of Sciences, Systems Research Institute,
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Jonathan Amezcua Patricia Melin
(cid:129)
Oscar Castillo
fi
New Classi cation Method
Based on Modular Neural
Networks with the LVQ
Algorithm and Type-2
Fuzzy Logic
123
JonathanAmezcua Oscar Castillo
Division of Graduate Studies Division of Graduate Studies
TijuanaInstitute of Technology TijuanaInstitute of Technology
Tijuana, BajaCalifornia Tijuana, BajaCalifornia
Mexico Mexico
Patricia Melin
Division of Graduate Studies
TijuanaInstitute of Technology
Tijuana, BajaCalifornia
Mexico
ISSN 2191-530X ISSN 2191-5318 (electronic)
SpringerBriefs inApplied SciencesandTechnology
ISSN 2520-8551 ISSN 2520-856X (electronic)
SpringerBriefs inComputational Intelligence
ISBN978-3-319-73772-0 ISBN978-3-319-73773-7 (eBook)
https://doi.org/10.1007/978-3-319-73773-7
LibraryofCongressControlNumber:2017962995
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Preface
Inthisbook,anewmodelfordataclassificationwasdeveloped.Thisnewmodelis
based on the competitive neural network learning vector quantization (LVQ) and
type-2 fuzzy logic. This computational model consists of the hybridization of the
aforementionedtechniques,usingafuzzylogicsystemwithinthecompetitivelayer
of the LVQ network to determine the shortest distance between a centroid and an
input vector.
This new model is based on a modular LVQ architecture to further improve its
performance on complex classification problems. It also implements a
data-similarity process for preprocessing the datasets, in order to build dynamic
architectures, having the classes with the highest degree of similarity in different
modules. Some architectures were developed in order to work mainly with two
datasets, an arrhythmia dataset (using ECG signals) for classifying 15 different
types ofarrhythmias,andasatelliteimagesegmentdatasetusedfor classifying six
different types of soil. Both datasets show interesting features that make them
interesting for testing new classification methods.
First, this book started with the optimization of some parameters of a modular
LVQnetworkarchitecture,andtheseparameterswerethenumberofclustercenters,
number of epochs for training, and the LVQs algorithm learning rate. The
bio-inspired metaheuristic method called particle swarm optimization (PSO) was
used for this purpose, showing good performance in this problem.
Afterward, afuzzyinferencesystem(FIS)wasdesignedanddevelopedinorder
toadaptittotheLVQscompetitivelayer.Thisfuzzysystemdeterminestheclosest
cluster center to an input vector, based on the distances computed by the LVQ
algorithm itself. Finally, this FIS was elevated into an interval type-2 fuzzy infer-
encesystem(IT2FIS).Eventhoughobtainedresultsarenotstatisticallyconclusive,
the hybridization in this new model generated favorable results under certain
conditions. The obtained results for this new model will also depend on the com-
plexity of the datasets to work with.
v
vi Preface
ThisresearchworkwaspartiallyfundedbyCONACYTandTijuanaInstituteof
Technology, and we would like to express our gratitude to both institutions. In
addition, we would like to thank Prof. Janusz Kacprzyk for always supporting and
encouraging us to perform good research in the computational intelligence area.
Tijuana, Mexico Dr. Jonathan Amezcua
November 2017 Prof. Patricia Melin
Prof. Oscar Castillo
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Theory and Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Artificial Neural Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 History of Artificial Neural Networks . . . . . . . . . . . . . . . . . . . . . 6
2.3 Neural Networks Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3.1 Input Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3.2 Activation Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3.3 Output Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3.4 Learning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.4 Supervised Learning Neural Networks. . . . . . . . . . . . . . . . . . . . . 10
2.4.1 Perceptron. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.4.2 Multilayer Perceptron. . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.4.3 MLPs Backpropagation Algorithm . . . . . . . . . . . . . . . . . . 12
2.5 Unsupervised Learning Neural Networks . . . . . . . . . . . . . . . . . . . 12
2.5.1 Competitive Learning. . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.5.2 Learning Vector Quantization. . . . . . . . . . . . . . . . . . . . . . 14
2.6 Modular Neural Networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.6.1 Characteristics of Modular Neural Networks . . . . . . . . . . . 16
2.7 Fuzzy Inference Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.7.1 Fuzzy Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.7.2 Membership Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.7.3 Fuzzy If-Then Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.7.4 Components of a Fuzzy Inference System. . . . . . . . . . . . . 23
2.8 Interval Type-2 Fuzzy Inference Systems. . . . . . . . . . . . . . . . . . . 24
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
vii
viii Contents
3 Problem Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.1 Datasets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.1.1 Arrhythmia Dataset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.1.2 Satellite Images Dataset . . . . . . . . . . . . . . . . . . . . . . . . . . 30
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4 Proposed Classification Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.1 Fuzz LVQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.2 Model Architectures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4.2.1 Data Similarity Process . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.2.2 Model Architectures for the Arrhythmia Dataset . . . . . . . . 39
4.2.3 Model Architectures for the Satellite Images Dataset . . . . . 39
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
5 Simulation Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
5.1 Arrhythmia Dataset Methods Description. . . . . . . . . . . . . . . . . . . 41
5.1.1 Arrhythmia Dataset Simulation Results. . . . . . . . . . . . . . . 42
5.1.2 Arrhythmia Dataset Statistical Analysis. . . . . . . . . . . . . . . 47
5.2 Satellite Images Dataset Methods Description. . . . . . . . . . . . . . . . 48
5.2.1 Satellite Images Dataset Simulation Results. . . . . . . . . . . . 49
5.2.2 Satellite Images Dataset Statistical Analysis . . . . . . . . . . . 52
Reference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
6 Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
6.1 Future Work. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Reference. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Appendix. .... .... .... .... ..... .... .... .... .... .... ..... .... 57
Index .... .... .... .... .... ..... .... .... .... .... .... ..... .... 73
Chapter 1
Introduction
A classification problem consists in categorizing an object based on certain attri-
butes, with the aim of identifying to which class it belongs to. For instance, a fruit
could be classified based on its size, color, or shape; the same way as an auto-
mobile, a flower, an animal, among others. All these objects have their own attri-
butes, and which attributes are considered for classifying an object (or event) will
depend on the problem to work with. For example, a heart disease could be clas-
sified using data obtained from a Holter device, a tumor or a cancer cell could be
classified based on the data of an image.
The list of classification problems is countless, and here is where many classi-
fication algorithms emerge [1, 2], for solving the majority of all these kinds of
problems. Most of these algorithms work with feature vectors of the objects, in
these vectors the objects attributes are described, in order to be learned by the
classification algorithm. Depending on the algorithm to work with, the features in
thesevectorscanbebinary,real-valued,categorical, etc.Forinstance,toclassifya
tumor based on an image, the feature vector would be composed by the values of
the pixels in the image.
According to [3], the classification process is composed by four basic
components:
(cid:129) Class, represented by a label, and used on the object after its classification.
(cid:129) Attributes of the object to be classified (defined in the feature vectors).
(cid:129) Training dataset, which is used for training the classification model, to rec-
ognize the appropriate class based on the available attributes.
(cid:129) Testing dataset, containing the new data that should be classified by the
classification model.
©TheAuthor(s),underexclusivelicencetoSpringerInternationalPublishingAG, 1
partofSpringerNature2018
J.Amezcuaetal.,NewClassificationMethodBasedonModularNeuralNetworks
withtheLVQAlgorithmandType-2FuzzyLogic,SpringerBriefsinComputational
Intelligence,https://doi.org/10.1007/978-3-319-73773-7_1
Description:In this book a new model for data classification was developed. This new model is based on the competitive neural network Learning Vector Quantization (LVQ) and type-2 fuzzy logic. This computational model consists of the hybridization of the aforementioned techniques, using a fuzzy logic system wit