This book constitutes the refereed proceedings of the 12th International Conference on Rough Sets, Fuzzy Sets, Data Mining, and Granular Computing, RSFDGrC 2009, held in Delhi, India in December 2009 in conjunction with the Third International Conference on Pattern Recognition and Machine Intelligence, PReMI 2009. RSFDGrC 2009 is the core component of a broader Rough Set Year in India initiative, RSIndia09.

Plenary Papers and Reports.- Affordance Relations.- Discovering Concurrent Process Models in Data: A Rough Set Approach.- Intelligent Science.- Pattern Structures for Analyzing Complex Data.- Fuzzy Sets and Rough Sets for Scenario Modelling and Analysis.- Innovation Game as a Tool of Chance Discovery.- Rough Set Year in India 2009.- Foundations of Rough Sets and Beyond.- An Algebraic Semantics for the Logic of Multiple-Source Approximation Systems.- Towards an Algebraic Approach for Cover Based Rough Semantics and Combinations of Approximation Spaces.- New Approach in Defining Rough Approximations.- Rough Set Approximations Based on Granular Labels.- On a Criterion of Similarity between Partitions Based on Rough Set Theory.- On Rough Sets with Structures and Properties.- A Formal Concept Analysis Approach to Rough Data Tables.- Covering Based Approaches to Rough Sets and Implication Lattices.- A Logical Reasoning System of Before-after Relation Based on Bf-EVALPSN.- Some Proof Theoretic Results Depending on Context from the Perspective of Graded Consequence.- Rough Set Algorithms and Applications.- IQuickReduct: An Improvement to Quick Reduct Algorithm.- Dynamic Reduct from Partially Uncertain Data Using Rough Sets.- Approximation of Loss and Risk in Selected Granular Systems.- An Efficient Gene Selection Algorithm Based on Tolerance Rough Set Theory.- Rough Set Based Social Networking Framework to Retrieve User-Centric Information.- Use of Fuzzy Rough Set Attribute Reduction in High Scent Web Page Recommendations.- A Rough Sets Approach for Personalized Support of Face Recognition.- Taking Fuzzy-Rough Application to Mars.- Rough Image Colour Quantisation.- of Speech (POS) Tag Sets Reduction and Analysis Using Rough Set Techniques.- Fuzzy Set Foundations and Applications.- More on Intuitionistic Fuzzy Soft Sets.- On Fuzzy Contra ?-Irresolute Maps.- On Fuzzy Strongly ?-I-Open Sets.- Lattice Structures of Rough Fuzzy Sets.- Analysis of Ergodicity of a Fuzzy Possibilistic Markov Model.- A Fuzzy Random Variable Approach to Restructuring of Rough Sets through Statistical Test.- A New Approach for Solving Fuzzy Maximal Flow Problems.- Peptic Ulcer Detection Using DNA Nanorobot Based on Fuzzy Logic Rules.- Investigations on Benefits Generated By Using Fuzzy Numbers in A TOPSIS Model Developed For Automated Guided Vehicle Selection Problem.- A Multi-criteria Interval-Valued Intuitionistic Fuzzy Group Decision Making for Supplier Selection with TOPSIS Method.- Data Mining and Knowledge Discovery.- The Lower System, the Upper System and Rules with Stability Factor in Non-deterministic Information Systems.- Learning Player Behaviors in Real Time Strategy Games from Real Data.- An Efficient Prediction Model for Diabetic Database Using Soft Computing Techniques.- A Decision Making Model for Vendor-Buyer Inventory Systems.- Software Reliability Prediction Using Group Method of Data Handling.- Mining Temporal Patterns for Humanoid Robot Using Pattern Growth Method.- Multiscale Comparison of Three-Dimensional Trajectories: A Preliminary Step.- Time Series Forecasting Using Hybrid Neuro-Fuzzy Regression Model.- A Fast Support Vector Machine Classification Algorithm Based on Karush-Kuhn-Tucker Conditions.- Data Mining Using Rules Extracted from SVM: An Application to Churn Prediction in Bank Credit Cards.- Clustering and Current Trends in Computing.- Interval Set Cluster Analysis: A Re-formulation.- Rough Entropy Based k-Means Clustering.- Fast Single-Link Clustering Method Based on Tolerance Rough Set Model.- A Novel Possibilistic Fuzzy LeaderClustering Algorithm.- Projected Gustafson Kessel Clustering.- Improved Visual Clustering through Unsupervised Dimensionality Reduction.- An Improved Cluster Oriented Fuzzy Decision Trees.- Combining Naive-Bayesian Classifier and Genetic Clustering for Effective Anomaly Based Intrusion Detection.- Ant Colony Optimisation Classification for Gene Expression Data Analysis.- A Comparative Performance Analysis of Multiple Trial Vectors Differential Evolution and Classical Differential Evolution Variants.- Information Retrieval and Text Mining.- Granular Computing for Text Mining: New Research Challenges and Opportunities.- Polarity Classification of Subjective Words Using Common-Sense Knowledge-Base.- A Weighted Hybrid Fuzzy Result Merging Model for Metasearch.- Comparing Temporal Behavior of Phrases on Multiple Indexes with a Burst Word Detection Method.- A Comparative Study of Pattern Matching Algorithms on Sequences.- BPBM: An Algorithm for String Matching with Wildcards and Length Constraints.