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Fuzzy Logic and GeoMedia

Supervisors:

Prof. Dr. Dietrich Schröder

Prof. Dr. Franz-Josef Behr

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Agenda

Introduction Objectives Literature review Study area and Data Scope of GeoMedia software Fuzzy logic approach Boolean logic Fuzzy and Boolean Comparisions Fuzzy Command Tool Conclusions

About Me Work Project on MapWindow

ActiveX Inception of VnRPToolkit

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Introduction

Site selection process - a screening technique

Factors for selection of land fill (slope, river, road,

geology, land use, etc.)

Factors for restrictions (environmental, economic, social

and legislative factors.)

Boolean logic and Fuzzy logic

Objective

Formulation of membership functions

Primary goal - creation of generic Tool.

Comparison of the results

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Literature Review

Conventional use of Fuzzy Logic - control systems

Successful Implementation – analysis,and classification

of RS.

GIS software packages.

IDRISI called FUZSIG.

No incorporation of generic tool for process automation

Fuzzy analysis - Extensive and laborious analysis.

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Study area and Data

Figure 3 : Map of Study Area

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Scope of GeoMedia Software

GeoMedia Professional 6.1

GeoMedia Grid 6.1 – An extension

Single GIS environment

Provides generic tools for manual fuzzy analysis

Customization through VB, Visual C++ and Visual C#

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Theory of Fuzzy Logic

Lotfi Zadeh, Fuzzy Sets (1965).

Fuzzy logic – Described to cope with fuzziness.

Fuzzy sets – A superset of conventional (Boolean) logic

MF range – 0 to 1.

Reasoning using linguistic terms.

If the distance is short then assign 0 membership

(a) Boolean Logic. (b) Fuzzy Logic.0 1 10 0.2 0.4 0.6 0.8 100 1 10

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Characteristic Function:Let X be the universe of discourse with elements x. Then for

Boolean logic the Characteristic function fA(x) of A

fA(x): X → {0, 1},where fA(x) = 1 if x is totally in A;fA(x) = 0 if x is not in A;

However for a Fuzzy set A we have

μA(x): X → [0, 1], where μA(x) = 1 if x is totally in A;μA(x) = 0 if x is not in A;0 < μA(x) < 1 if x is partly in A.

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An exampleThe degree of Fuzzy sets is shown as follows:

Layers Membership function

SettlementsMF = 0, if x < 500 MF = 1, if x > 1500 MF = ((x-500)/1000), if 500 ≤ x ≤ 1500

Figure 1:Visual interpretation of Membership Function with respective graphs

Membership FunctionsLayers Membership function

Slope MF = 1, if 0 <x<5MF = ((x-5)/10), if 5≤x≤15 MF = 0, if x>15

Aspect

MF = 0, if 225≤x≤315 MF = ((x-135)/90) if 135<x<225MF = ((x-315)/90) if 315<x<45 (315<x<405)MF = 1, if 45≤x≤135MF = 1, if x=361(flat areas)

WellsMF = 0, if x<200 MF = ((x-400)/200), if 400≤x≤600MF = 1, if x>600

RiverMF = 0, if x<250 MF = ((x-250)/500), if 250≤x≤750MF = 1, if x>750

Road MF = 0, if x>500 MF = ((500-x)/500), if 0<x≤500

settlementsMF = 0, if x<250 MF = ((x-500)/1000), if 500≤x≤1500MF =1, if x>1500

GeologyMF = 0, if x > +125 MF = ((125-x)/250), if -125≤x≤+125MF = 1, if x < -125

Fuzzy logic with basic analysis tool

Settlement0

1500 Void

500 m

1500 m Void

0 Membarship

1 Membarship Void

1 Membarship

Void0 Membarship

1 Membarship

0 Membarship

1 Membarship

0 Membarship

1 Membarship

Fuzzy logic Analysis

00.10.20.30.40.50.60.70.80.91

Legend

SlopeRoads

Aspect

Settlement

Wells

Aquifer

Rivers

Fuzzy analysis results for Optimum sites

Minimum Function

0 Membarship

1 Membarship

Product operation

0 Membarship

1 Membarship

Addition operation with a threshold value of 5

Suitable areas

Boolean Analysis

Wells distance = 500m

Roads distance=500m

Rivers distance = 500m

Settlement distance = 1000mMinor Aquifer

Slope < 10 degrees

0<Aspect <180

Boolean analysis results for optimum sites

Fuzzy and Boolean Comparisions

0 Membarship

1 Membarship Boolean resultant areas

Minimum Function

Fuzzy and Boolean Comparisions

Boolean - sharp distinction with “YES” and “NO” areas Fuzzy - gradual delineation for selected landfill Flexibility to decide on threshold for fuzzy logic

No need for repeated analysis No need for change in criteria and rules Saves time and reduces effort

Decisions on threshold can be supplimented by field work

The Fuzzy Command Tool

Input section

Process Section

Output section

To specify ascending or descending from a layer

Command buttons

Context Help

Results of fuzzy command tool

UnsuitableSuitable

Rivers

Roads

Wells

Settlement

Conclusions

Successful implementation of the generic tool

Applicability of the tool to any layer except for complicated fuzzy functions.

Illustrates the Need for customizable GIS software's.

Demonstrates GeoMedia Grid as an example of software providing the framework for customizing applications

Conclusions

Future Work – To improve upon the different functions other than linear.

Future Work – customizing complicated fuzzy functions if the process is recurring.

About Me

B.Sc. Maths, Physics and Geology M.Sc. Geology (Osmania University, Hyderabad, India) M.Sc. Geoinformatics (HFT, Stuttgart, Germany)

Work Research Associate (Software Developer) Currently doing a job as a Software Engineer

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Current Job Project – Integration of MapWindowGIS

Integration of MapWindowGIS into SAFIRA II MMS software

Softwares and languages used

MapWindowGIS Libraries

MapWindow Active X Components

Visual Basic 6

MapWindowGIS

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GIS application made using MapWindowGIS

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Possibilities on Selection

Different capabilities on polygon selection

Single selection Multiple selectionMultiple selection

Switch selection Multi De-selection Single De-selection

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Final integration of MapWinGIS project

Final Integration of MapWinGIS application into SAFIRA MMS

Inception of MapWindow

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