Publications

Stochastic (max,+) linear systems

  • J.K. Kim and H. Ayhan, Tandem Queues with Subexponential Service Times and Finite Buffers, Queueing Systems 66, (2010), 195-209.
  • H. Ayhan and J.K. Kim, A General Class of Closed Fork and Join Queues with Subexponential Service Times, Stochastic Models , 23, (2007), 523–535
  • H. Ayhan, Asymptotics of Closed Fork and Join Queues with Subexponential Service Times, [paper: paper ]
  • H. Ayhan , Zbigniew Palmowski and Sabine Schelegel, Cyclic Queueing Networks with Subexponential Service Times , Journal of Applied Probability, 41, (2004), 791-801.
  • H. Ayhan and D-W. Seo, Tail Probability of Transient and Stationary Waiting Times in (max,+)-Linear Systems , IEEE Trans. on Automatic Control , 47-1, (2002), 151-157 ,
  • H. Ayhan and D-W. Seo, Laplace Transform and Moments of Waiting Times in (Max,+) Linear Systems with Poisson Input, QUESTA., 37, (2001), 405-438.
  • H. Ayhan and F. Baccelli, Expansions for Joint Laplace Transform of Stationary Waiting Times in (Max,+) Linear Systems with Poisson Input, QUESTA. , 37, (2001), 291-328. , full paper: full (376 Kbytes)
  • A.F. de Kort, B. Heidergott and H. Ayhan, A Probabilistic (max,+) Approach for Determining Railway Infrastructure Capacity, EJOR , 148, (2003), 644-661.
  • H. Ayhan and M.A. Wortman, , Job Flow Control in Assembly Operations, IEEE Trans. on Automatic Control , 44, (1999), 864-868.
  • H. Ayhan and M.A. Wortman, , An Approximation for Computing the Throughput of Closed Assembly-Type Queueing Networks, EJOR , 112, (1999), 107-121

Series Expansions

  • H. Ayhan and S. Schlegel, Expansion Formulae for Characteristics of Cumulative Cost in Finite Horizon Production Models, EJOR, 132, (2001), 50-61.
    The fourth, fifth and sixth papers in the above category also fit into this area of research.

Markov Decision Processes with applications to admission and production/inventory control

  • S. Andradottir , H. Ayhan, and D. G. Down , Optimal Assignment of Servers to Tasks when Collaboration is Inefficient, under review, [paper: paper ].
  • H. Eser Kirkizlar, S. Andradottir , and H. Ayhan, Service Quality versus Efficiency in Tandem Systems, under review , [paper: paper ].
  • H. Eser Kirkizlar, S. Andradottir , and H. Ayhan, Flexible Servers in Tandem Lines with Setups, under revision , [paper: paper ].
  • Bo Zhang and H. Ayhan, Optimal Admission Control for Tandem Queues with Loss, to appear, IEEE Transactions on Automatic Control .
  • S. Andradottir , H. Ayhan, and D. G. Down , Design Principles for Flexible Systems, under review , [paper: paper ].
  • H. Eser Kirkizlar, S. Andradottir , and H. Ayhan, Flexible Servers in Understaffed Tandem Lines, to appear, POMS
  • H. Eser Kirkizlar, S. Andradottir , and H. Ayhan, Robustness of Effective Server Assignment Policies to Service Time Distributions, Naval Research Logistics , 57, (2010), 563-582.
  • S. Andradottir , H. Ayhan, and D. G. Down , Queueing Systems with Synergistic Servers, Operations Research, 59, (2011), 772–780.
  • S. Andradottir , H. Ayhan, and D. G. Down , Maximizing the Throughput of Tandem Lines with Flexible Failure-Prone Servers and Finite Buffers, Probability in Engineering and Informational Sciences, 22, (2008), 191–211
  • S. Ziya , H. Ayhan, and R. D. Foley , Optimal Pricing for Finite Capacity Queueing Systens with Multiple Customer Classes, Naval Research Logistics, 55, (2008), 412–418.
  • I. Maoui, H. Ayhan, and R. D. Foley , Congestion Dependent Pricing in a Stochastic Service System, Advances in Applied Probability, 39, (2007), 898–921.
  • S. Andradottir , H. Ayhan, and D. G. Down , Dynamic Assignment of Dedicated and flexible Servers in tandem Lines, Probability in Engineering and Informational Sciences, 21, (2007), 497–538
  • I. Maoui, H. Ayhan, and R. D. Foley , Optimal Static Pricing for a Service Facility with Holding Costs, to appear EJOR
  • T. Aktaran-Kalayci, and H. Ayhan, Sensitivity of Optimal Prices to System Parameters in a Service Facility, EJOR, 193, (2009), 120–128
  • S. Ziya , H. Ayhan, R. D. Foley, and E. Pekoz , A Monotonicity Result for the Blocking Probability in a G/GI/c/m Queueing System, Journal of Applied Probability,43, (2006), 1201–1205.
  • S. Ziya , H. Ayhan, and R. D. Foley , Optimal Pricing for Finite Capacity Queueing Systems, OR Letters 34, (2006) 214-218.
  • S. Ziya , H. Ayhan, and R. D. Foley , Relationships Among Three Assumptions in Revenue Management, Operations Research 52, (2004) 804-809.
  • S. Andradottir , H. Ayhan, and D. G. Down , Compensating for Failures with Flexible Servers, Operations Research, 55, (2007), 753–768.
  • S. Andradottir , and H. Ayhan , Throughput Maximization for Tandem Lines with Two Stations and Flexible Servers, Operations Research 53, (2005) 516-531.
  • S. Andradottir , H. Ayhan, and D. G. Down , Dynamic Server Allocation for Queueing Networks with Flexible Servers, Operations Research 51, (2003) 952-968
  • S. Andradottir , H. Ayhan, and D. G. Down , Server Assignment Policies for Maximizing the Steady-State Throghput of Finite Queueing Sytems, Management Science 47, (2001) 1421-1439
  • M. Lewis , H. Ayhan, and R. D. Foley , Optimal Admission Policies for a Multi-Class Nonstationary Queueing System, Journal of Applied Probability. 39, (2002) 20-37.
  • M. Lewis , H. Ayhan, and R. D. Foley , Bias Optimality in a Queue with Admission Control, Probability in the Engineering and Informational Sciences. 13, (1999), 309-327.
  • H. Arslan, H. Ayhan, and T.L. Olsen ,Analytic Models for When and How to Expedite in Make-To-Order Systems, IIE Transactions, 33 (2001) 1019-1029.

Others

  • J. Chang, H. Ayhan, J.G. Dai and Cathy H. Xia , Dynamic scheduling of a multiclass fluid model with transient overload, QUESTA 48, (2004) 263-307 longer version.
  • H. Ayhan and T.L. Olsen , Scheduling of a Multi-Class Single Server Queue Under Non-Traditional Performance Measures, Operations Research , 48, (2000), 482-489.
  • H. Ayhan, J. Limon-Robles and M.A. Wortman, On the Time-Dependent Occupancy and Backlog Distributions for the $GI/G/\infty$ Queue, Journal of Applied Probability , 36, 1999, 558-569.
  • H. Ayhan, J. Limon-Robles and M.A. Wortman, An Approach for Computing Tight Numerical Bounds on Renewal Functions, IEEE Trans. on Reliability , 48, 1999, 182-188.
  • G-A. Klutke, , M.A. Wortman, and H. Ayhan, The Availability of Inspected Systems Subjected to Random Deterioration, Probability in the Engineering and Informational Sciences. , 10, 1996, 109-118.
  • M.A. Wortman, ,G-A. Klutke, , and H. Ayhan, A Maintenance Strategy for Systems Subjected to Deterioration Governed by Random Shocks, IEEE Trans. on Reliability , 43, (1994), 439-445.