Mini Project Report Design and implementation of a classification system based on soft computing and statistical approaches Submitted By: Ashish Kumar Agrawal(2001114)
Mini Project Report
Design and implementation of a classification system based on soft computing
and statistical approaches
Submitted By:
Ashish Kumar Agrawal(2001114)
Abstract
I
This project, being developed as a part of MHRD research
project (Designing an Intelligent Robot for Explosive Detection and
Decontamination funded by MHRD, Govt. of India), explores the
design and development of classifier based on statistical methods and
soft computing based approaches which is capable of identifying the
mines and non mines using various clustering, classification and rules
establishment algorithms as to compare the algorithm on the basis of
complexity and accuracy. Designing such a classifier is a big challenge
because data is not linearly separable and since it has overlapping
features, it is not possible to design a classifier with 100% accuracy
.This project deals with PVC tubes, wood piece and copper cylinders as
non mine data in addition to data of various mines. The basic idea of
the classification is based on a fact that it is safe if the non-mines data
is predicted as mine but it is not the case when we predict mines data as
non-mines. So the unsupervised learning based ART algorithm divides
the data into several clusters which are merged on the basis of above
fact. Genetic algorithm is enhancing the results to establish the results
having negation in the antecedent part. In addition to these approaches,
fuzzy approaches also give the membership values corresponding to
each class to visual the class of data in better way.
Candidate’s Declaration
I hereby declare that the work presented in this project titled “Design and implementation of a classification system based on soft computing and statistical approach” submitted towards completion of mini-project in sixth Semester of B.Tech (IT) at the Indian Institute of Information Technology (IIIT), Allahabad. It is an authentic record of my original work pursued under the guidance of Dr. G. C. Nandi, Associate Professor, IIIT, Allahabad. I have not submitted the matter embodied in this project for the award of any other degree. (Ashish Kumar Agrawal) Place: Allahabad Date: 17-5-2004 ------------------------------------------------------------------------------------------------------------
Certificate
This is to certify that the above declaration made by the candidate is correct to the best of my knowledge and belief.
(Dr G.C. Nandi)
Associate Professor
Place: Allahabad IIIT (Deemed University)
Date: May, 2004 Deoghat, Jhalwa, Allahabad.
II
Acknowledgement First and foremost, I would like to express my sincere
gratitude to my project guide, Dr G.C. Nandi. I was privileged to
experience a sustained enthusiastic and involved interest from his side.
This fueled my enthusiasm even further and encouraged us to boldly
step into what was a totally dark and unexplored expanse before us.
I would also like to thank my seniors who were ready with a positive
comment all the time, whether it was an off-hand comment to encourage
us or a constructive piece of criticism and a special thank to JRC
database provider who arranged a good database for mines.
Last but not least, I would like to thank the IIIT-A staff members and
the institute, in general, for extending a helping hand at every juncture
of need.
Ashish Kumar Agrawal (2001114)
III
Table Of Contents
Abstract………………………………………………………………..….I
Declaration………………………………………………………………..II
Certificate…………………………………………………………………II
Acknowledgements……………………………………………………….III
List Of Figures………………………………………………………… VII
CHAPTER I
Introduction and Statement Of Problem………………………………....1
1.1 Introduction…………………………………………………………1
1.2 Problem Statement………………………………………………….1
CHAPTER II
Challenges In This Field ..………………………………………………...3
2.1 Features extraction …..……………………………………………..3
2.2 Selection of an algorithm………..……………………………….…3
CHAPTER III
Approaches in This Direction…..………………………………………...4
3.1 stat ist ical Approaches. .……………………………………...4
3.1.1 Clustering algorithm Kmean .. . .…………………………….4
3.1.2 k-nearest neighbour……..…………………………………..4
3.2 Softcomputing………………………………………………………5
3.2.1 Genetic algorithm ……………………………………………5
3.2.2 Adaptive resonance theory (ART)….…………………….....6
3.2.3 Fuzzy C-mean………………………………………………...7
3.2.4. Gustavson kessel algorithm………………………………...8
3.2.5 Gath–geva algorithm…………………………………….…..8
3.2.6 Kohonen SOM…………………………………………….….9
IV
CHAPTER IV
System Architecture……...………………………………………………10
4.1 Data Source Name and login….…………………………………..10
4.2 Algorithm and table selection……………………………………..10
CHAPTER V
Results And Conclusions…………………………………………………12
5.1 Results……………………………………………………………...12
5.2 conclusion …………………………………………………………15
5.3 Future Extensions…….…..………………………………………….15
5.3.1 Improvement in the genetic algorithm…………………..………16
5.3.2.Distributed computing environment……………………….16
5.3.3.Dealing with various platform and format………………...16
References ……………………………………………………………….. 17
-Books ……………………………………………………………………17
- Research Papers………………………………………………………..17
V
List of Figures
Fig 1: Flow of information………………………………………....…11
Fig 2: Main frame of algorithm……………………………………..…11
Fig 3: Result of genetic algorithm……….. ….………………………12
Fig 4: Result of ART………………………..…………………………12
Fig 5: Result of Fuzzy c-mean and Gustavson kessel algorithm
……………………………………………………………………………..13
Fig 6: Result of k-mean algorithm.... . .………………..……..……….14
Fig 7: Result of k-nearest neighbour algorithm….….……………….14
Fig 8: Result of kohonen SOM….…….……..……………………….15
VI
VII
Chapter 1
Introduction & Statement of ProblemBRIEF OVERVIEW
1 .1 Introduction
“If we already know about the upcoming hazards; it is very easy to find
the way to abolish it.”
Here, this sentence is being described in the context of Landmine
Detection and Decontamination. My objective is to predict
whether at a particular point of working area is occupied by mines
or not, with some confidence parameter. Robot is designed to
move toward these predicted areas to decontaminate the mines.
These mines occupied area can be known before initiation of robot
movements or can be predicted dynamically, so to design an
obstacles free path for robot is another aspect beyond the domain
of this module.
To tackle this problem a classification toolkit has been designed using
some statistical and soft computing based approaches to cluster
the data, to predict the possible class of incoming data, to generate
some rules in the term of confidence parameter. The data may be
given in image form or some tabular form having all numeric or
categorized attributes.
It is impossible to design a classifier having 100% right classification
because it is not easy to differentiate between the data of metallic
debris, PVC tubes and actual mine data.
On the basis of this prediction path designers develop the obstacle free
path to decontaminate these mines.
1
1 .2 Statement OF Problem
2
Anti-Personal landmines are a significant barrier to economic and social
development in a number of countries, so we need a classification
system that can differentiate a mine from metallic debris on the
basis of given data. This data is generated by some highly accurate
sensors.
Chapter 2
Challenges in This Field
In the field of classification and rules establishment, the basic problems
are the features extraction (building blocks of algorithms) and
selection of good algorithms those can generate results with high
certainty value.
2.1 Features Extract ion
The initial problem is the problem of features extraction. Generally the
image data is given having a blurred image of an object, so it is
very difficult to extract the exact boundary of object. There may
be various features those can be used as the raw material of
system. Here blobsize, blobaspectratio and blobintensity have been
chosen. The given data may contain the images of PVC tube,
metallic debris and Mines.
The data in some tabular format having numerical or categorized
values of attributes can also be given, which is more suitable for
the algorithms
2.2 select ion of an Algori thm
The second problem is to choose an algorithm that can interpret the
problem in best way. The algorithms can be categorized in two
parts:
(1)Statistical approaches
(2)Softcomputing based approaches
The three types of algorithms can be applied here: Classification,
Clustering and Rules establishment with some certainty factor, so
the best way is to design various algorithms and then check their
efficiency and accuracy.
3
Chapter 3
APPROACHES IN THIS DIRECTION
In this section the various algorithms will be discussed being used to
achieve the objective.
3 .1 Stat ist ical Approaches
Two algorithms have been used one for clustering (K-mean algorithm)
and another for prediction of class of incoming data (K-nearest
neighbour).
3.1 .1 Cluster ing Algori thm: Kmean
Clustering is a nonlinear activity that generates ideas, images and
feelings around a stimulus word. Clustering may be a class or an
individual activity.
If the number of data is less than the number of cluster then we
assign each data as the centroid of the cluster. Each centroid will
have a cluster number. If the number of data is bigger than the
number of cluster, for each data, we calculate the distance to all
centroid and get the minimum distance. This data is said belong to
the cluster that has minimum distance from this data. Since we are
not sure about the location of the centroid, we need to adjust the
centroid location based on the current updated data. Then we
assign all the data to this new centroid. This process is repeated
until no data is moving to another cluster anymore. Mathematically
this loop can be proved to be convergent
Since there are only two classes mine and non-mine so number of
classes is given 2 as input with the dataset [B1].
4
3.1 .2 K-nearest Neighbour
5
K-nearest neighbour technique is used to predict the class of
incoming data on the basis of given training data and density
estimator (k-nn) to estimate the confidence of the incoming
sample for a particular class. Finally the class is predicted having
the highest estimator.
Density estimator: qc(x) = (number of neighbors of class c)/K
The neighbors are the k closest point to the given sample .Their mutual distances are calculated by city block distance. [B2]
The problem of choosing k still remains, but a general rule of thumb is to use
K= sqrt(N).
Where N is the number of learning samples.
A disadvantage of this method is that it is computationally intensive for large data sets.
3 .2 Softcomputing approaches
Softcomput ing approaches can be c lass i f ied in to severa l ca tegor ies
l ike :
1 . ) Neura l approaches
2 . ) Fuzzy c luster ing
3 . ) Adapt ive resonance theory
4 . ) Kohonen SOM
5. ) Genet ic a lgor i thm
3 .2 .1 Genetic a lgori thm to establ ish rules
To establ i sh the ru les between the a t t r ibutes of data
assoc ia t ion ru le but association Rule mining cannot predict the
complete set of rules, i .e. the rules which have negation in the
attributes cannot be discovered. To overcome that disadvantage,
Genetic Algorithms (GAs) has been used.
F i rs t of a l l assoc ia t ion ru le i s appl ied wi th some support and
conf idence va lues entered by user to generate some base ru les
6
and these ru les a re sent to genet ic a lgor i thm as input which
he lps to evolve some new ru le hav ing negat ion in a t t r ibutes .
The three bas ic par t of genet ic a lgor i thm are as fo l low:
(a )Select ion : Roulet te whee l technique i s used to se lect the two
parents [R1] .
(b)Crossover : A random point (crossover po int ) i s generated and
the segment to the le f t of th is point of f i r s t parent and that of
second parent are interchanged.
(c )Mutation : mutat ion point i s generated randomly and the b i t
va lue a t th is point i s togg led .
After some i tera t ion we f ind some ru les fo l lowing the above
propert ies and hav ing h igh f i tness va lue that can be ca lcu la ted
e i ther us ing the conf idence va lue or by confus ion matr ix .
3.2.2 Adaptive resonance theory (ART)
As we know backpropagation network is very powerful in the sense that
it can simulate any continuous function given a certain number of
hidden neurons and a certain forms of activation functions. But
once a back propagation is trained, the number of hidden neurons
and the weights are fixed. The network cannot learn from new
patterns unless the network is re-trained from scratch, so there is
no plasticity. [R2]
So ART is a new neural network technique to solve this problem.
Our ultimate objective is to cluster the data in several chunks.
Each time one by one samples from the data as input neurons is sent as
input and the activation value is calculated corresponding to each
of the existing output neurons, and the highest value is chosen ,if
this value is higher than threshold values then the weight of this
connection is updated otherwise a new output neuron is added.
After certain iteration it’s found that the proper clusters of the
data in our application don’t have classes more than two (mine and
non-mine). The another fact is that if a non-mine data is predicted
as mine it is acceptable but vice-versa is not true because it may be
dangerous, so among all the clusters, the cluster having the
cluster-center farthest from the mine data center is classified as
non-mine, rest of the clusters are classified as mine.
Here activation function is calculated as the city block distance of the
incoming normalized data and weights of connection.
3.2.3 Fuzzy c-mean:
In the c lass ica l c lus ter ing a lgor i thm we have the cr isp
membership of a c lass (e i ther one or zero) .but whi le
c lass i fy ing the mine data i t i s not very easy to d i f ferent ia te
between mine and non-mine . So we need a method that can te l l
the membership of the data in each c lass . I f th is membersh ip
is average then we dea l th is data as spec ia l data and c lass i fy
th is in the c lass of mine (as mine are dangerous ! ! ) . [R3]
where |X| is the feature vector
and p is the number of classes (p=2 in our case)
Membership values
Euclidean distance:
Mean center prototype:
7
Mean center
prototype(Ci)=
If the d i f ference of the membership va lue wi th prev ious
membership va lue i s less than threshold than a lgor i thm
terminate with hav ing the membership va lue for each c lass .
3.2.4Gustavson-Kessel Algorithm
It is an improvement of fuzzy c-mean clustering algorithm .the
correlation between the data is not considered in c mean. In this
algorithm we redefine our distance formula as: [R3]
Mahalobis distance :
where Ai is the mean center
prototype and xj and cj are
the sample attribute and
cluster center.
And covariance matrix is
calculated as :
Fuzzy covariance matrix
Mean center prototype
3.2.5 Gath-Geva Algorithm :
This algorithm assumes that data is normally distributed. [R3]
8
Distance :
where is the a-priori probability of data belonging to cluster i,
and Mean center prototype
The symbols have same explanation as above.
Before applying this algorithm it is suggested to analyze data whether it
is normally distributed or not.
3.2 .6 Kohonen SOM: A competitive network learns to categorize the input vectors presented to it. If a neural network just needs to learn to categorize its input vectors, then a competitive network will do. Competitive networks also learn the distribution of inputs by dedicating more neurons to classifying parts of the input space with higher densities of input.[B3] A self-organizing map learns to categorize input vectors. It also learns the distribution of input vectors. Feature maps allocate more neurons to recognize parts of the input space where many input vectors occur and allocate fewer neurons to parts of the input space where few input vectors occur. Self-organizing maps also learn the topology of their input vectors. Neurons next to each other in the network learn to respond to similar vectors. The layer of neurons can be imagined to be a rubber net that is stretched over the regions in the input space where input vectors occur. Self-organizing maps allow neurons that are neighbors to the winning neuron to output values. Thus the transition of output vectors is much smoother than that obtained with competitive layers, where only one neuron has an output at a time.
9
Now we have some brief knowledge of algorithms those have been implemented .Now I will discuss the architectural design of classification system followed by the results .
Chapter 4
System Architecture
As I have already discussed that input can have image form or tabular
form .Matlab has been used to extract the features from the input
images. We have the numerical attributes based table with the
entry whether the data belongs to mine or non-mine, but for the
genetic algorithm categorized table is required so data is
categorized in three categories :Low, Medium and High with class
value simply mine or non-mine.
4 .1 Data source name and login:
Data i s be ing mainta ined in MS Access . User i s f ree to enter any
data but he needs to conf igure the database f i r s t us ing (contro l
pane l ->adminis t ra t ive tool ->data sources(odbc)->system DSN
-> conf igure ) . After the conf igurat ion he wi l l be ass igned a
DSN name . th is DSN name is asked when u in i t i a l ize the
appl icat ion wi th the user name and password that can be
obta ined from help(Because th is i s des igned for demonstrat ion
so username and password have been g iven in he lp) . When
connect but ton i s pressed i f the username and password are
correct and the entered DSN ex ists , a new page opens having
a l l the a lgor i thms and tab le se lect ion fac i l i ty .
4 .2 Algori thm and table select ion
10
Any tab le ex is t ing in the input database can be se lected wi th the
a lgor i thm(Se lect ca tegor ized tab le i f u apply genet ic
a lgor i thm) .Now the a lgor i thm spec i f ic resu l ts wi l l be
d isp laced.
Different algorithm can ask for some input parameter like clustering
algorithm can ask for number of cluster etc.
The interface is self explanatory with proper help. Java language has
been used at front hand and Microsoft Access XP for Database in
back hand and JDBC Bridge to communicate between algorithms
and databases.
Fig 1: Flow of information
11Fig 2: Main frame of algorithms
Chapter 5
Result And Conclusion 5.1 Results : -
This module has successfully been implemented. The ultimate objective
of this module is to compare between various algorithms and
differentiate between them on the basis of their accuracy and
results.
Genetic algorithm:
Fig 3 : Result of genetic algorithm
This snapshot is displaying the result of both association rule and
genetic rules. It is very much clear that genetic algorithm has generated
the rule having negative attribute value in antecedent part so this
algorithm is very useful to establish rules.
ART
12 Fig 4 : Result of ART algorithm
the ART algorithm is also giving good rules .the ART gives the multiple
class distribution of given data. Because to predict a non-mine as a
mine is not as much dangerous as to predict a mine as non-mine,
so the all the cluster having more distance from the non-mine
center has been assigned mine class.
13
Fuzzy C-mean
The fuzzy c-mean algorithm is
giving rules with membership
value in each class. So it is
very easy to check some data
that can not be classified as
mine and non-mine, so this
type of data can be put into
mine class to avoid danger.
Gustavson kessel
This algorithm is abolishing the
drawback of fuzzy c-mean
algorithm because it
considers the correlation
between data.
Fig 5 : Result of Fuzzy c-mean and Gustavson kessel algorithm
Kmean Algorithm
Kmean algorithm is non-adaptive
and time consuming and
giving the accuracy of 65%.
Fig 6 : Result of Kmean algorithm
14
K nearest neighbour algorithm This algorithm is useful if
someone wants to know
the class of a given data.
First of all , the training
data must be given with
the inputs and the
number of nearest
neighbours. On the basis
of class of nearest
neighbours, this
algorithm predicts the
possible class of the input
data.
The algorithm gives good result
when number of K is
more which also makes
this algorithm very time
consuming.
Fig 7 : Result of Knearest neighbour algorithm
Kohonen SOM
This algorithm is also used for clustering and it’s quite a fast algorithm
based on ‘winner take all ’ strategy. It differentiates the mine and
non-mine up to 80% accuracy
Fig 8 : Result of Kohonen SOM algorithm
5.2 Conclusion
Al l the e ight d i f ferent a lgor i thms have been implemented to
compare the resu l ts . This c lass i f ie r i s g iv ing resu l t wi th 80%
accuracy .The best resu l t i s be ing g iven by ART and Genet ic
a lgor i thm. Fuzzy C-mean and Gustavson kesse l i s a l so good
because of membership va lues for each c lass . This module can
d if ferent ia te between the PVC tube , wood p iece ,brass tube
,copper cy l inder(Non mine data)and the mine data obta ined
from j rc Israe l (ht tp ://apl -database . j rc . i t ) .
15
16
5.3 Future Extension
We contemplate following future features which can be incorporated
into this project:-
5.3.1 Improvement in the genetic a lgori thm :the implemented
genetic algorithm in this module incorporates only point mutation,
so the other type of mutation can also be practiced like deletion
,insertion and segment mutation etc. and the crossover and
mutation probabilities can be modified to get better results.
5.3.2 Distributed computing environment: Generally we have to deal
with large databases because on the basis of 100 tuples databases it
is very hard to predict the exact class of data .In practical and real
l ife application we have several GB of data . To operate this much
of data we need the distributed databases and computing.
5.3.3 Dealing with various platforms and formats: The data may be
various format and databases system so system should be flexible
enough to handle the various formats and DBMSs like (Oracle
,MySql etc).
17
References
Books
B.1 Earl Gose Steve Jost Richard Johnsonbaugh Pattern Recognition
and Image Analysis June, 1996 0132364158 Prentice Hall.
B.2 Richard O. Duda, Peter E. Hart, David G. Stork (2001) Pattern
classification (2nd edition), Wiley, New York, ISBN 0471056693
B.3 Valluru B. Rao C++ Neural Networks and Fuzzy Logic second
edition.
Research Papers
R.1 Improvements in Genetic AlgorithmsJ. A. Vasconcelos, J. A. Ramírez, R. H. C. Taka hashi, and R. R. Saldanha . IEEE TRANSACTIONS ON MAGNETICS, VOL. 37, NO. 5, SEPTEMBER 2001. R.2 ART Neural Networks for Remote Sensing: Vegetation
Classification from Landsat TM and Terrain Data Gail A.
Carpenter, Marin N. Gjaja, Sucharita Gopal, and Curtis E.
Woodcock.
R.3. Bezdek, J.C., Pal, S.K., 1992: Fuzzy Models for Pattern Recognition. IEEE Press, New York.