Publications

Ph.D. dissertation
Many-Server Queues with Time-Varying Arrivals, Customer Abandonment and Non-exponential Distributions. 
Adviser: Ward Whitt


Papers published and accepted

  • A Network of Time-Varying Many-Server Fluid Queues with Customer Abandonment. Operations Research, vol. 59, July-August 2011, pp. 835-846. (With Ward Whitt) [PDF]
    • e-Companion. [PDF]
    • Longer version. [PDF]
  • Large-Time Asymptotics for the Gt/Mt/st+GIt Many-Server Fluid Queues with Abandonment. Queueing Systems, vol. 67, 2011, pp. 145-182. (With Ward Whitt) [PDF]
  • Nearly Periodic Behavior in the The Overloaded G/D/S+GI Queue. Stochastic Systems, vol. 1, No. 2, 2011, p. 340-410. (With Ward Whitt) [PDF]
    • Appendix [PDF]
  • A Fluid Approximation for Large-Scale Service SystemsPerformance Evaluation Review, Special issue on 2011 MAMA conference. [PDF]
  • The Gt/GI/st+GI Many-Server Fluid Queue. Queueing Systems, vol. 71, No. 4, 2012, pp. 405-444. (With Ward Whitt) [PDF]
    • Longer version. [PDF]
  • Stabilizing Customer Abandonment in Many-Server Queues with Time-Varying Arrivals. Operations Research, vol. 60, No. 6, 2012, pp. 1551-1564. (With Ward Whitt) [PDF]
    • e-Companion. [PDF]
    • Longer version. [PDF]
  • A Many-Server Fluid Limit for the Gt/GI/st+GI Queueing Model experiencing Periods of Overloading. Operations Research Letters, vol. 40, No. 5, 2012, pp. 307-312. (With Ward Whitt) [PDF]
  • Introduction to Levy Processes. Encyclopedia of Operations Research and Management Science. 2013. (With Chien-Chia Huang) [PDF]
  • Algorithms for Time-Varying Networks of Many-Server Fluid Queues. INFORMS Journal on Computing. vol. 26, No. 1, 2014, pp. 59-73. (With Ward Whitt) [PDF]
    • e-CompanionAlgorithms for Time-Varying Networks of Many-Server Fluid Queues: e-CompanionINFORMS Journal on Computing, vol. 26, No. 1, 2014. (With Ward Whitt) [PDF].
  • Many-Server Heavy-Traffic Limits for Queues with Time-Varying ParametersAnnals of Applied Probability. vol. 24, No. 1, 2014, pp. 378-421. (With Ward Whitt) [PDF
  • Stabilizing Performance in Networks of Queues with Time-Varying Arrival Rates. Probability in the Engineering and Informational Sciences. vol. 28, No. 4, 2014, pp. 419-449. (With Ward Whitt) [PDF]
    • Appendix [PDF]
  • A Law of Iterated Logarithm for Multiclass Queues with Preemptive Priority Service Discipline. Queueing Systems. vol. 79, 2015, pp. 251-291.(With Yongjiang Guo) [PDF]
  • Combined Inversion and Thinning Methods for Simulating Nonstationary Non-Poisson Arrival Processes. Proceedings of the 2015 Winter Simulation Conference. (With Ran Liu, Michael E. Kuhl and James R. Wilson) [PDF]
  • Approximations for Heavily-Loaded G/GI/n+GI Queues. Naval Research Logistics, vol. 63, 2016, pp. 187-217. (With Ward Whitt and Yao Yu) [PDF]
    • Appendix [PDF]
  • Staffing a Service System with Non-Poisson Nonstationary Arrivals. Probability in the Engineering and Informational Sciences, vol. 30, 2016, pp. 593-621. (With Beixiang He and Ward Whitt) [PDF]
  • Stabilizing Performance in a Service System with Time-Varying Arrivals and Customer Feedback. European Journal of Operational Research, vol. 256, No. 2, 2017, pp. 473-486. (With Ward Whitt) [PDF]
    • Appendix [PDF]
  • Allocation Heuristics for High-Altitude Long-Endurance UAV Image Intelligence Platforms. Military Operations Research. vol. 22, No. 3, 2017, pp. 3-19. (With Gi-Young Kim, Thom Hodgson, Russell King, and Michael Kay) [PDF]
  • Heavy-Traffic Limit for Initial Content Process. Stochastic Systems. vol. 7, No. 1, 2017, pp. 95 – 142. (With Korhan Aras and Ward Whitt) [PDF]
    • Appendix [PDF]
  • Functional Law of Iterated Logarithm for Multi-Server Queues with Batch Arrivals and Customer Feedback. Annals of Operations Research. vol. 264, No. 1, 2018, pp. 157-191. (With Yongjiang Guo and Renhu Pei) [PDF]
  • Staffing to Stabilize the Tail Probability of Delay in Service Systems with Time-Varying Demand.
    Operations Research. Vol. 66, No. 2, 2018, pp. 514-534. Winner of the 2016 INFORMS JFIG competition (first place) [PDF]
    • e-Companion [PDF]
    • Longer online appendix [PDF]
  • Many-Server Gaussian Limits for Non-Markovian Queues with Customer Abandonment. Queueing Systems, Special Issue in honor of Ward Whitt’s 75th birthday, Vol. 89, No. 1, 2018, pp. 81-125. (With Korhan Aras and Xinyun Chen) [PDF]
    • Longer online appendix [PDF]
  • Modeling and Simulation of Nonstationary Non-Poisson Processes. Forthcoming at INFORMS Journal on Computing. (With Ran Liu, Michael E. Kuhl and James R. Wilson) [PDF]
    • Appendix [PDF]

Working papers

  • To Queue or Not to Queue: Queueing Design for Large-Scale Service Systems. (With Ping Cao, Junfei Huang and Shuangchi He) [PDF]
  • Reducing Delays in Retrial Queues by Simultaneously Differentiating Service Rates and Retrial rates. Submitted to Operations Research. (With Jinting Wang and Zhongbin Wang) [PDF]
  • Staffing and Scheduling in TIme-Varying Multiclass Service Systems to Achieve Service Level Differentiation. (With Kyle Hovey and Xu Sun) [PDF]
  • Assessing Uncertainty & Risk in an Expeditionary Military Logistics Network. Submitted to Military Operations Research. (with Brandon McConnell, Thom J. Hodgson, Russell E. King, Greg H. Parlier, James R. Wilson, Michael G. Kay, Kristin Thoney-Barletta) [PDF]
  • Optimal Control in Flexible Production Systems with Perishable Inventory and Nonstationary Demand. (With Chihoon Lee, Xin Liu and Ling Zhang) [PDF]
  • Dynamic Pricing in One-Way Car Sharing Networks: A Distributional Fluid Approximation Approach. (With Shuangchi He, Yang Liu and Ling Zhang) [PDF]
  • Optimal Controls to Remote Queues. (With Shuangchi He and Yao Yu) [PDF]
  • A Functional Law of the Iterated Logarithm for Multi-Class Queues with Batch Arrivals. (With Yongjiang Guo) [PDF]
  • Physician Staffing in Emergency Department via Multi-class Multi-Stage Network: Opening the Blackbox. (With Caglar Caglayan, Turgay Ayer, Mustafa Sir, Kalyan Pasupathy, David Nestler)
  • Approximations for the Time-varying Nonexponential Queues. (With Ward Whitt and Yao Yu)
  • A Functional Weak Law of Large Numbers for the Time-Varying (Gt/GI/st+GI)m/Mt Queueing Network. Working paper. (With Korhan Aras) [PDF]
  • A Fluid Model for the Multi-Class Network Queues with Time-Varying Arrivals and Prescribed Routing Paths.

Papers with students

  • Beixiang He (graduated in August 2014)
    • Ph.D. DissertationMulti-Class Queueing Networks with Time-Varying Arrivals: Performance Approximations and Staffing Design.
    • Staffing a Service System with Non-Poisson Nonstationary Arrivals. Probability in the Engineering and Information Sciences, vol. 30, 2016, pp. 593-621. (With Beixiang He and Ward Whitt) [PDF]
  • A. Korhan Aras (graduated in March 2016)
    • Ph.D. Dissertation: Two-Parameter Heavy-Traffic Limits for Queues with Non-Exponential Service and Patience Times.
    • A Functional Weak Law of Large Numbers for the Time-Varying (G_t/GI/s_t+GI)^m/M_t Queueing Network. [PDF]
    • Heavy-Traffic Limit for Initial Content ProcessStochastic Systems.  vol. 7, No. 1, 2017, pp. 95 – 142. (With Ward Whitt) [PDF]
    • Many-Server Gaussian Limit for Queues with Customer Abandonment and Non-Exponential Service Times. Submitted to Queueing Systems, Special Issue in honor of Ward Whitt’s 75th birthday. (With Korhan Aras and Xinyun Chen) [PDF]
  • Yao Yu (graduated in March 2017)
    • Ph.D. Dissertation: Performance Approximations and Controls to Queueing Networks
    • Approximations for Heavily-Loaded G/GI/n+GI Queues. Naval Research Logistics, vol. 63, 2016, pp. 187-217. (With Ward Whitt) [PDF] – Appendix [PDF]
    • Optimal controls to Remote Queues. Working paper. (With Shuangchi He)
  • Ling Zhang (Ongoing)
    • Ph.D. Dissertation: Optimal Controls in Time-Varying Service Networks: Asymptotic Effectiveness and Performance Optimization 
    • Dynamic Pricing in One-Way Car Sharing Networks: A Distributional Fluid Approximation Approach. Working paper. (With Yang Liu and Shuangchi He) [PDF]
    • Optimal Control of Double-Ended Queues with Abandonment and Nonstationary Demand. (With Chihoon Lee and Xin Liu)
  • Kyle Hovey (Ongoing)
    • Ph.D. Dissertation: Optimal Staffing in Nonstationary Service Networks.