DataBases & Data Mining Joined Specialization Project„Data Mining Classification

Tool”

By Mateusz Żochowski

& Jakub Strzemżalski

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Agenda

General description of the problem Functionality Data Mining aspects

Algorithm and optimisation Data Base aspects

General entities scheme

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General Description

Universal Tool Different kinds of objects (e.g.

preprocessed photos, hospital patients data)

Finding similar objects Decision problems

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Functionality

Independent system – user operated Using sets of data already provided or

uploading new types Influence on the way data is processed

Possible usage in bigger systems as a processing engine Additional module used as a helping

tool in more complex systems

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General Use Case

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Data Mining General Ideas

Description of a object Definition of a distance

K-NN algorithm Brief explanations of the algorithm

Optimization Problem of comparing large number of

objects Optimized solution – using grouping idea

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Definitions Objects

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K-NN

K – Nearest Neighbors Idea standing behind k-nn Aim - finding k-similar objects to the

one we are analyzing and eventually assigning appropriate decision

Method - calculating distance from analyzed object to the others in our database and finding the closest ones

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K-NN Graphical representation

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Definitions Distance

Calculations in multidimensional space Coefficients

Alfa wi – weights – underlining importance of

particular attributes n – number of all the attributes

)()( 21

1

21 *),( oaoa ii

in

i

iwOOD

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Optimalisation

The reason – cost of multidimensional distance computation for 1-all elements

Solution – improved Knn Result – better efficiency because

of reduced number of distance computations due to narrowed set of possibly similar objects

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Step 1 - Group-oriented plane division

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Step 2 – new Object appeares

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Step 3

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Step 4

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Step 5

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Grouping problem

The problem – assigning object into appropriate groups according to chosen distance definition

Solution – some clustering algorithm

Brief example – k-means algorithm

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DataBase – entities

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DataBase General structure of database

results from optimization issues Due to universal purpose of the

system database may contain many different tables of objects

Need of using system tables for defining experiments

Group Member as a temporary table ?

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Summary

There is still a lot of work to do...