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Example Applications of Rough Sets Theory – A Survey. Christopher Chretien Laurentian University Sudbury, Ontario Canada October 2002. Introduction. Research on the application of Rough Sets Theory Discovering possible areas of application Further understanding of Rough Sets Theory usage.
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Example Applications of Rough Sets Theory – A Survey Christopher Chretien Laurentian University Sudbury, Ontario Canada October 2002
Introduction • Research on the application of Rough Sets Theory • Discovering possible areas of application • Further understanding of Rough Sets Theory usage
References • Lixiang Shen, Francis E. H. Tay, Liangsheng Qu and Yudi Shen (2000), Fault Diagnosis using Rough Sets Theory , Computers in Industry, vol. 43, Issue 1, 1 August 2000, pp.61-72., URL:www.geocities.com/roughset/Fault_diagnosis_using_rough_sets_theory.pdf • Israel E. Chen-Jimenez, Andrew Kornecki, Janusz Zalewski, Software Safety Analysis Using Rough Sets, URL:http://www-ece.engr.ucf.edu/~jza/classes/6885/rough.ps • Francis E. H. Tay and Lixiang Shen (2002), Economic and Financial Prediction using Rough Sets Model , European Journal of Operational Research 141, pp.643-661, URL:http://www.geocities.com/roughset/EJOR.pdf • Pawan Lingras (2001), Unsupervised Rough Set Classification Using GAs Journal of Intelligent Information Systems, 16, 215–228, found on: CiteSeer, URL:http://citeseer.nj.nec.com/cs • Rapp, S., Jessen, M. and Dogil, G. (1994). Using Rough Sets Theory to Predict German Word Stress. in: Nebel, B. and Dreschler-Fischer, L. (Eds.) KI-94: Advances in Artificial Intelligence, Lecture Notes in Artificial Intelligence 861, Springer-Verlag, URL:www.ims.uni-stuttgart.de/~rapp/ki94full.ps
Fault Diagnosis using Rough Sets Theory • Diagnosis of a valve fault for a multi-cylinder diesel engine • Rough Sets Theory is used to analyze the decision table composed of attributes extracted from the vibration signals
Fault Diagnosis using Rough Sets Theory • 4 states are studied among the signal characteristics • Normal state • Intake valve clearance is too small • Intake valve clearance is too large • Exhaust valve clearance is too large
Fault Diagnosis using Rough Sets Theory • 3 sampling points selected to collect vibration signals • 1st cylinder head • 2nd cylinder head • centre of the piston stroke on the surface of the cylinder block
Fault Diagnosis using Rough Sets Theory • 6 attributes • Frequency domain attributes: IF, CG • Time domain attributes: IT, σ, Dx, α4 • 18 attributes for decision table • 1 decision attribute with 4 possible values based on states
Software Safety Analysis using Rough Sets • Investigates the safety aspects of computer software in safety-critical applications • Assessment of software safety using qualitative evaluations
Software Safety Analysis using Rough Sets • Use of checklists to collect data on software quality • Waterfall model • Project Planning • Specification of requirements • Design • Implementation and integration • Verification and validation • Operation and maintenance
Software Safety Analysis using Rough Sets • 8 student teams developing safety-related software • Device control over the internet • Elevator controller • Air traffic control system • System satellite control system
Software Safety Analysis using Rough Sets • 150 questions about the first 5 phases of the waterfall model • Overall safety level for 6 of the 8 projects was around 60%
Economic and Financial Prediction using Rough Sets Model • Applications of Rough Sets model in economic and financial prediction • Emphasis on main areas of business failure prediction, database marketing and financial investment
Economic and Financial Prediction using Rough Sets Model • Business failure prediction • ETEVA • Database Marketing • Financial Investment • TSE
Using Rough Set Theory to Predict German Word Stress • Prediction of German word stress by extracting symbolic rules from sample data • Symbolic rules are induced with a machine learning approach based on Rough Sets Theory
Using Rough Set Theory to Predict German Word Stress • Variable Precision Rough Sets Model • An elementary class belongs to RβX iff a (100% - β) majority of it’s elements belongs to X • An elementary class does not belong to URβX iff a (100% - β) majority of its elements does not belong to X
Using Rough Set Theory to Predict German Word Stress • Corpus • Monomorphemic words • At least 2 non-schwa syllables • Nouns • 242 words
Using Rough Set Theory to Predict German Word Stress • Attributes: Typ, Onset, Hoeche, Laenge, Spannung, Coda • 36 attributes in total • Attributes aligned ‘from right to left’ • Decision attribute with possible values of final, penult and antepenult
Using Rough Set Theory to Predict German Word Stress • 1st experiment • Stress assignment operates from right to left • 2nd experiment • Estimate predictive accuracy • 3rd experiment • Remove length information
Unsupervised Rough Set Classification using GAs • Rough Set classification using Genetic Algorithms • Highway classification based on predominant usage
Unsupervised Rough Set Classification using GAs • Applications of GAs • Job shop scheduling • Training neural nets • Image feature extraction • Image feature identification
Unsupervised Rough Set Classification using GAs • Rough Set classification scheme • Both uh and uk are in the same lower approximation A(Xi). • Object uh is in a lower approximation and uk is in the corresponding upper approximation UA(Xi) • Both uh and uk are in the same upper approximation
Unsupervised Rough Set Classification using GAs • Total error of rough set classification is the weighted sum of these errors
Unsupervised Rough Set Classification using GAs • Rough classification of highways • PTC sites • Roads classified on the basis of trip purposes and trip length characteristics • Classes: commuter, business, long distance and recreational highways • Traffic patterns: hourly, daily, monthly
Unsupervised Rough Set Classification using GAs • Experiment • 264 monthly traffic patterns on Alberta highways (1987-1991) • Rough genome consisted of 264 genes • Classes: commuter/business, long distance, recreational
Conclusion • Triggering a better understanding of Rough Sets Theory • Opening eyes to different fields of application