Emmanuel Fernandez ECECS Dept. Univ. Cincinnati Emmanuel Fernandez Associate Professor emmanuel@ececs.uc.edu Emmanuel Fernandez ECECS Dept. Univ. Cincinnati INTERESTS Telecommunications Information Technology Algorithms, Software Tools Stochastic Models, Decision & Control Processes, Dynamic Programming Operations & Logistics: Semiconductor fabs Basic Methodology Emmanuel Fernandez ECECS Dept. Univ. Cincinnati OVERVIEW • Phase 1: 1990-1996: Learning and Adaptive Systems, Models • • with Partial Information, Average Optimality Criteria. Phase 2: 1994-1998: Non-standard Optimality Criteria, Modeling Applications, Algorithms & Software Tools. Phase 3: 1998-Present: Risk-Sensitive Models, Security & Fault Management in Telecommunication Networks, Operational Methods in Semiconductor Manufacturing. • Over 61 refereed publications(6 b, 18+ j, 37 c) • Four Ph.D.s, 3 M.Sc., 18+ undergrad. RA’s. • Honors: – Tau Beta Pi Professor of the Year, David Rist Prize MORS, IEEE Life Member Fund Research Initiation Award (Eng. Foundation). Emmanuel Fernandez ECECS Dept. Univ. Cincinnati OUTLINE • Motivation: Applications – Semiconductor manufacturing operations – Logistics – Information Networks o Fault & Security Management in communication networks o Routing in the Intelligent Network • Stochastic Decision & Control Models: • Optimality Criteria: Why Risk-Sensitivity? • Basic Research Risk sensitive results: – Optimality equations & the Vanishing Discount Approach (AC). – Modular functions & structured policies (DC). Emmanuel Fernandez ECECS Dept. Univ. Cincinnati APPLICATIONS • Semiconductor Manufacturing: – Capacity expansion & allocation, – Preventive maintenance scheduling (AMD). • Information Networks: – Routing in the Intelligent Network (AT&T); – Security & fault management.. • Operations & Logistics: – Workforce management; – Scheduling military training resources (Army). Emmanuel Fernandez ECECS Dept. Univ. Cincinnati Semiconductor Manufacturing: Capacity Expansion & Allocation • NSF/SRC Project at U. Maryland (PI’s: M. Fu & S. Marcus) • EF Sabbatical project (begun Fall 98) • EF liaison with industry (AMD) during 99 • Integrate transient product dynamics over entire fab life cycle: Markov Decision Process (MDP) models • • • • • – allocating/adding tool and process capacity – dynamic uncertain demands (e.g., market shifts) – transient dynamics (e.g., technology shrinks/shifts) Computational Investigation & Cost Modeling Tool: SYSCODE (University of Arizona software) – Stochastic Systems Control and Decision Algorithms Software Laboratory Find optimal policy for different parameters : – demand distribution – inventory cost and/or backlogging cost Simple policies vs. optimal policy Infinite horizon results vs. finite horizon A Markov Decision Process Model for Capacity Expansion and Allocation: IEEE Conf. Decision & Control, 1999. Emmanuel Fernandez ECECS Dept. Univ. Cincinnati Industry Interaction: Advanced Micro Devices • Joint effort UA & ISR • On-site visits • Preventive maintenance – Within allowed window, when to do PM? • Information Technology: – – – – “Torrents” of information! Inefficient “manual” methods Do not use available information No models • Develop basic models & solution SRC/ISMT Emmanuel Fernandez ECECS Dept. Univ. Cincinnati Information Technology & Telecommunication Networks • Routing calls in the Intelligent Network • Security and Fault Management • Software and Web tools: – SYSCODE – Computations & MATLAB Web course. Emmanuel Fernandez ECECS Dept. Univ. Cincinnati The Intelligent Network: Routing Toll-free Calls (AT&T) • AT&T - UA project • Route 800- traffic to • call centers State information: – Workload at call centers – Incomplete information – Periodic updates • Solution: – POMDP model – Heuristic Policy Iteration Algorithm R. Milito & E. Fernandez: (a) IEEE TAC 1995, (b) IEEE Conf. Decision & Control 1995 Emmanuel Fernandez ECECS Dept. Univ. Cincinnati Information Networks: Security and Fault Management • Joint project with M. Shayman, • U. Maryland. Searching for faults in a given domain: – Scheduling tests • Single/Multiple faults • Test sequence constraints • Risk-sensitive criterion • Interchange argument: – Explicit scheduling rules • Qualitative analysis • Security intrusions: – Similar to fault management •1999 Allerton Conference •IEEE TAC 2001 •Proposals Emmanuel Fernandez ECECS Dept. Univ. Cincinnati Operations & Logistics: Scheduling Army Training Resources • LTC M. McGinnis: Ph.D. UA • Thousands of recruits/year • Many installations/bases • Decisions: – Company size – Length of training period – Number of companies to activate/retire each week. • Model: Inventory-type • Solution: Heuristic Policy • Iteration Algorithm Decision support software (in use by Army). Journal Military Op. Res. 1996 (Winner of David Rist Prize) Emmanuel Fernandez ECECS Dept. Univ. Cincinnati Operations & Logistics: Scheduling Army Training Resources Emmanuel Fernandez ECECS Dept. Univ. Cincinnati Logistics: Workforce Management • Recruit-retain-dismiss individuals • Intrinsic individual’s potential – Unobservable state • Random productivity – Bayesian stochastic model • The firm’s lifetime is long: – Average cost criterion • Adaptive control through Bayesian • learning Qualitative analysis of case studies Fdez, Jain, Lee, Rao, Rao: Management Science 1995.