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Teacher Assignment Program. Maria Lizarraga Project Defense Master of Computer Science Tuesday June 29, 2010 Department of Computer Science University of Colorado, Colorado Springs. Agenda. Introduction Background Information Solution Test Results Lessons Learned Future Research
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Teacher Assignment Program Maria Lizarraga Project Defense Master of Computer Science Tuesday June 29, 2010 Department of Computer Science University of Colorado, Colorado Springs Lizarraga
Agenda • Introduction • Background Information • Solution • Test Results • Lessons Learned • Future Research • Summary Lizarraga
Introduction • High School Timetabling Problem • Scheduling Problem Lizarraga
Scheduling Models Lizarraga
School Timetabling Problem Find: xijk (i = 1,….,m; j = 1,…,n; k= 1,…,p) Where: xijk = 0 or 1 (i = 1,…,m; j=1,…,n; k=1,…,p) Scheduling Component - Class Teacher Period Such that: p xijk = rij (i = 1,…,n; j=1,…,n) k=1 n xijk= 1 (i = 1,…,m; k=1,…,p) j=1 m xijk= 1 (j = 1,…,n; k=1,…,p) i=1 Course Objective Function: m n p min wijkxijk i = 1 j = 1 k = 1 Lizarraga
Local Search Neighborhood Neighborhood Selection Lizarraga
Genetic Algorithms Lizarraga
Ant Colony Optimization Lizarraga
Related Research • Michael Clark, Martin Henz, Bruce Love, QuikFix A Repair-based Timetable Solver, In Proceedings of the 7 th PATAT Conference, (2008) • Defu Zhang, Yongkai Liu, Stephen C.H. Leung, A simulated annealing with a new neighborhood based algorithm for high school timetabling problems, Proceedings of the first ACM/SIGEVO Summit on Genetic and Evolutionary Computation, pp 381-386 • Aldy Gunawan, K. M. Ng, H. L. Ong, A Genetic Algorithm for the Teacher Assignment Problem for a University in Indonesia, Information and Management Sciences, Vol. 19 No. 1. pp 1-16, 2008 • Djasli Djamarus, Ku Ruhana Ku-Mahamud, Heuristic Factors in Ant System Algorithm for Course Timetabling Problem, isda, pp.232-236, 2009 Ninth International Conference on Intelligent Systems Design and Applications, 2009 Lizarraga
Problem Definition • Machine Environment • Flexible Flow Shop • Constraints • Objective Function • total weight of all violated constraints Lizarraga
Solution • Teacher Assignment Program Lizarraga
Strategic Tabu Search Algorithm Lizarraga
Select class to swap Switch teacher with classes within same period Switch with unassigned teachers within same period Neighborhood Selection Lizarraga
Mutation Lizarraga
Speed Test Lizarraga
Random vs Strategic Lizarraga
Tabu List Size Lizarraga
Equalized Weights Random Neighborhood Selection Strategic Neighborhood Selection Lizarraga
Lessons Learned • Application requirement versus constraint • Tailoring solution to problem • Remove concept of hard and soft constraints Lizarraga
Further Research • Tabu list for each period • Dynamically changing the weights when stuck in a local minimum • Dynamically changing to Random Neighborhood Selection when stuck in local minimum • Investigate how to have multiple course sections Lizarraga
Summary • Sensitive to the number of constraints • Strategic Neighborhood selection performs better than Random Neighborhood select, (speed and quality) • Size of Tabu List made little difference • Equalizing weights can help escape local minimum Lizarraga
Questions Lizarraga
Supplemental Slides Lizarraga
Tabu Search Candidate Selection Lizarraga
Simulated Annealing Candidate Selection • Acceptance Probability Function e (-/T) Where: = selectedNeighbor.OFV – candidate.OFV T = current temperature • Cool Rate Tn = a * Tn-1 Lizarraga
Neighborhood Examples Lizarraga