University of Patras Department of Mathematics

Ioannis Dimitriou
Department of Mathematics
University of Patras
26500, Patras, Greece

Office: B/M 232
Email: idimit@math.upatras.gr
Phone: +302610 996774
Fax:

Position Lecturer
Organization University of Patras
Department Mathematics
Division Statistics, Probability and Operational Research

Biography

Since July 2014, I am a Lecturer at the Dept of Mathematics, University of Patras, Greece. I was a postdoctoral researcher at the Dept. of Electrical and Electronic Engineering, Imperial College, London, UK (October 2011-July 2012), at FORTH, Greece (September 2013-July 2014), at the Dept. of Mathematics, Aristotle University of Thessaloniki, Greece (January-December 2013) and at INRIA, Sophia Antipolis (MAESTRO) through the ABCDE ERCIM fellowship program (May-July 2014, Marie Curie Actions).


Research activities

My research interests focus on queueing theory, applied probability and performance modelling of computer and communication networks.


2nd International Mini-Symposium on Stochastic Models: Methods and Applications (SAMMA 2017)

I co-organize with Dr. Tuan Phung-Duc (Tokyo Institute of Technology, Tokyo, Japan), and Dr. Eleni Vatamidou University of Lausanne, Switzerland) the 2nd Mini-Symposium on Stochastic Models: Methods and Applications (SAMMA 2017), in conjunction with the 15th International Conference of Numerical Analysis and Applied Mathematics (ICNAAM 2017), 25-30 September 2017, The MET Hotel, Thessaloniki, Greece. For further information, visit the website SAMMA 2017. See also the website of the 1st SAMMA 2016


Publications

Papers in Journals/Chapters

  • E. Morozov, I. Dimitriou, (2017). Stability Analysis of a Multiclass Retrial System with Coupled Orbit Queues. Springer Verlag Lecture Notes in Computer Science (LNCS), vol. 10497, pp. 85-98.
  • I. Dimitriou, N. Pappas, (2017). Stable Throughput and Delay Analysis of a Channel-Aware Adaptive Random Access Wireless Network. Springer Verlag Lecture Notes in Computer Science (LNCS), vol. 10378, pp. 63-80.
  • I. Dimitriou, (2017). Modeling and Analysis of a Relay-Assisted Cooperative Cognitive Network. Springer Verlag Lecture Notes in Computer Science (LNCS), vol. 10378, pp. 47-62.
  • I. Dimitriou, (2017). Dynamic balancing in finite processor sharing queues with guard bandwidth policy, multiclass retrial users and signals. Performance Evaluation 114, pp. 1-15.
  • I. Dimitriou, (2017). A queueing system for modeling cooperative wireless networks with coupled relay nodes and synchronized packet arrivals. Performance Evaluation 114, pp. 16-31.
  • I. Dimitriou, (2017). A two class retrial system with coupled orbit queues. Probability in the Engineering and Informational Sciences 31 (2), pp. 139-179.
  • G. Fortetsanakis, I. Dimitriou, M. Papadopouli, (2017). A Game-Theoretical Analysis of Wireless Markets using Network Aggregation. IEEE Transactions on Mobile Computing 16(3), pp. 602-616.
  • I. Dimitriou, (2016). A retrial queue to model a two-relay cooperative wireless system with simultaneous packet reception. Springer Verlag Lecture Notes in Computer Science (LNCS), vol. 9845, pp 123-139.
  • I. Dimitriou, (2016). A queueing model with two types of retrial customers and paired services. Annals of Operations Research 238 (1), pp. 123-143.
  • I. Dimitriou, (2016). Queueing analysis of the DRX power saving mechanism in fault-tolerant 3GPP LTE wireless networks. Annals of Operations Research 239(2), pp. 521-552
  • I. Dimitriou, S. Alouf, A. Jean-Marie, (2015). A Markovian queueing system for modeling a smart green base station. Springer Verlag Lecture Notes in Computer Science (LNCS), vol 9272, pp. 3-18.
  • I. Dimitriou, (2015). Performance modeling of cellular systems with nite processor sharing queues in random environment, guard policy and flex retrial users. Springer Verlag Lecture Notes in Computer Science (LNCS), vol 9081, pp. 43-58.
  • I. Dimitriou, (2015). A retrial queue for modelling fault-tolerant performance systems with checkpointing and rollback-recovery. Computers & Industrial Engineering, vol 79, pp. 156-167.
  • I. Dimitriou, (2014). A queueing system with probabilistic inhomogeneous vacations for modeling power-saving in wireless systems with retransmissions. In: Czachorski T., Gelenbe E., Lent R. (eds) Information Sciences and Systems 2014. Springer, Cham.
  • I. Dimitriou, (2014). A modified vacation queueing model and its application on the Discontinuous Reception power saving mechanism in unreliable Long Term Evolution networks. Performance Evaluation, vol 77, pp. 37-56.
  • I. Dimitriou, (2013). A batch arrival priority queue with recurrent repeated demands, admission control and hybrid failure recovery discipline. Applied Mathematics and Computation, vol 219 (24), pp 11327-11340.
  • I. Dimitriou. (2013). A mixed priority retrial queue with negative arrivals, unreliable server and multiple vacations. Applied Mathematical Modelling, vol 37(3), pp 1295-1309.
  • I. Dimitriou, (2013). Analysis of a priority retrial queue with dependent vacation scheme and application to energy saving in wireless communication systems. The Computer Journal, vol 56 (11), pp 1363-1380 (online first 2012).
  • I. Dimitriou. (2013). A preemptive resume priority retrial queue with state dependent arrivals, unreliable server and negative customers. TOP, vol 21 (3), pp 542-571 (online first 2011).
  • C. Langaris, I. Dimitriou. (2010). A queueing system with n-phases of service and (n-1)-types of retrial customers, European Journal of Operational Research, vol 205, Issue 3, pp 638-649.
  • I. Dimitriou, C. Langaris. (2010). A repairable queueing model with two-phase service, start-up times and retrial customers, Computers and Operations Research, vol 37, Issue 7, pp 1181-1190.
  • I. Dimitriou, C. Langaris. (2009). A queueing model with start-up/close-down times and retrial customers, Stochastic Models, vol 25, Issue 2, pp 248-269.
  • I. Dimitriou, C. Langaris. (2008). Analysis of a retrial queue with two-phase service and server vacations, Queueing Systems, vol 60 (1-2), pp 111-129.

Submitted/Under review

  • I. Dimitriou, N. Pappas, Stable Throughput and Delay Analysis of a Random Access Network With Queue-Aware Transmission, Submitted, IEEE Transactions on Wireless Communications. April 2017. [arXiv:1704:02902]
  • I. Dimitriou, N. Pappas, Performance Analysis of an Adaptive Two-user Random Access Scheme, Submitted, August 2017.
  • N. Pappas, Z. Chen, I. Dimitriou, Throughput and Delay Analysis of Wireless Caching Helper Systems with Random Availability, Submitted, August 2017.
  • I. Dimitriou, N. Pappas, Performance Analysis of a Cooperative Wireless Network with Adaptive Relays: A Network-Level Study, Submitted, April 2017.

Papers in refereed conferences

  • E. Morozov, I. Dimitriou, (2017). Stability Analysis of a Multiclass Retrial System with Coupled Orbit Queues. Accepted for presentation in the 14th European Workshop on Performance Engineering (EPEW 2017) Berlin, Germany, September 7-8 2017.
  • I. Dimitriou, (2017). A system with coupled processors and simultaneous arrivals. AIP Conference Proceedings 1863, 200007 (2017); doi: http://dx.doi.org/10.1063/1.4992378 (Proceedings of SAMMA 2016, ICNAAM)
  • I. Dimitriou, N. Pappas, (2017). Stable Throughput and Delay Analysis of a Channel-Aware Adaptive Random Access Wireless Network. Accepted in the 24rd International Conference on Analytical & Stochastic Modelling Techniques & Applications (ASMTA 2017), Newcastle, UK.
  • I. Dimitriou, (2017). Performance analysis of a relay-assisted cooperative cognitive network. Accepted in the 24rd International Conference on Analytical & Stochastic Modelling Techniques & Applications (ASMTA 2017), Newcastle, UK.
  • I. Dimitriou, (2016). A retrial queue to model a two-relay cooperative wireless system with simultaneous packet reception. Accepted in the 23rd International Conference on Analytical & Stochastic Modelling Techniques & Applications (ASMTA 2016), Cardiff, Wales, UK. 24-26 August 2016.
  • I. Dimitriou, (2016). Two-class retrial queues for modeling cooperative wireless networks with coupled relay nodes, Accepted for presentation in the 11th International Workshop on Retrial queues (WRQ 2016), Amsterdam, Netherlands, August 31-September 2, 2016.
  • I. Dimitriou, (2016). A queueing system to model cooperative wireless networks with coupled relay nodes and simultaneous packet reception. Accepted for presentation in the 2nd European Conference on Queueing Theory (ECQT 2016), Toulouse, France, 18-20 July 2016.
  • I. Dimitriou, (2015). A two-class retrial system with coupled orbit queues. 18th INFORMS Applied Probability Conference held on the campus of Koc University in Istanbul, Turkey. July 5th - 8th, 2015 .
  • I. Dimitriou, S. Alouf, A. Jean-Marie, (2015). A Markovian queueing system for modeling a smart green base station. Presented in the 12th European Workshop on Performance Engineering (EPEW 2015) Madrid, Spain, 31 August and 1 September, 2015.
  • I. Dimitriou, (2015). Performance modeling of cellular systems with nite processor sharing queues in random environment, guard policy and ex retrial users. Presented in 22nd International Conference on Analytical & Stochastic Modelling Techniques & Applications (ASMTA 2015), Albena, Bulgaria, 26-29 May 2015.
  • I. Dimitriou, (2015). On a two coupled processor system with negative customers. 10th International Conference on Stochastic Models of Manufacturing and Service Operations - SMMSO 2015, Volos, Greece, 1-6 June 2015.
  • I. Dimitriou, (2014). A retrial queue with two-types of customers and paired services. Accepted for presentation at the First European Conference on Queueing Theory (ECQT 2014), Ghent, Belgium, 20-22 August 2014.
  • I. Dimitriou, (2014). A queueing system with probabilistic inhomogeneous vacations for modeling power-saving in wireless systems with retransmissions. Accepted for presentation at the 29th International Symposium on Computer and Information Sciences, Krakow, Poland, October 27-28th, 2014.
  • I. Dimitriou, (2012). Analysis of a priority retrial queue with dependent vacation scheme and application to energy saving in wireless communication systems. Presented in 9th International Workshop on Retrial Queues (WRQ), Pablo de Olavide University, Seville, Spain, 28-30 June 2012.
  • I. Dimitriou, (2012). An unreliable vacation queueing model and its application on the DRX mechanism for power saving in 3GPP LTE. Imperial College Energy and Performance Colloquium (ICEP 2012), Imperial College London, 29 May-1 June 2012.
  • I. Dimitriou, C. Langaris, (2008). A queueing system with n phases of service, vacations and retrial customers. 7th International Workshop on Retrial Queues, Athens, Greece, July 17-19, 2008.

Other publications

  • I. Dimitriou. (2009). A gated type multiclass retrial queue with structured batch arrivals, priorities and vacations. Technical Report, Department of Mathematics, University of Ioannina, Number 20, Volume June-December 2009, pp 1-13.
  • I. Dimitriou. (2012). A multiserver queue with vacations and timers in Markovian environment for managing energy consumption in data centers. Imperial College, Technical report, May 2012.

Referee for Journals

I am a regular reviewer for the following peer review journals

  • Computers and Operations Research
  • Journal of Systems Science and Systems Engineering
  • Central European Journal of Operational Research
  • Applied Mathematical Modelling
  • Operational Research
  • Queueing Systems
  • Asia Pacific Journal of Operational Research
  • Mathematical and Computer Modelling
  • International Journal of Computer Mathematics
  • Quality Technology and Quantitative Management
  • IEEE Transactions on Wireless Communications
  • IEEE Communication Letters
  • IEEE Transactions on Communications
  • Annals of Operations Research
  • KSII Transactions on Internet and Information Systems
  • Performance Evaluation
  • Applied Mathematics and Computation
  • European Journal of Operational Research
  • Computers and Industrial Engineering
  • Computer Networks
  • RAIRO - Operations Research
  • ACM Transactions on Modeling and Performance Evaluation of Computing Systems (TOMPECS)
  • Methodology and Computing in Applied Probability
  • SIAM Journal of Applied Mathematics
  • Annals of Telecommunications

    Contribution to International Conferences

  • Program Committee Member for the 23rd International Conference on Analytical & Stochastic Modelling Techniques & Applications (ASMTA 2016).
  • Co-Organizer of the 1st Symposium on Stochastic Models: Methods and Applications (SAMMA 2016), 14th International Conference of Numerical Analysis and Applied Mathematics, 19-25 September 2016, Rodos Palace Hotel, Rhodes, Greece.
  • Program Committee Member for the 24rd International Conference on Analytical & Stochastic Modelling Techniques & Applications (ASMTA 2017).
  • Co-Organizer of the 2nd Symposium on Stochastic Models: Methods and Applications (SAMMA 2017), 15th International Conference of Numerical Analysis and Applied Mathematics, 25-30 September 2016, The MET Hotel, Thessaloniki, Greece.

    Referee for Research Proposals

  • Research Foundation -- Flanders (FWO), Belgium (2017). [Website. ]

    Invited talks

  • I. Dimitriou. (2016). Two-class retrial queues for modeling cooperative wireless networks with coupled relay nodes. MAESTRO group, INRIA, 7 September 2016
  • I. Dimitriou. (2013). Multiclass retrial queues with preemptive priorities. Invited talk in the 7th Young European Queueing Theorists (YEQT IIV) workshop held in EURANDOM/TU Eindhoven in November 4-5-6, 2013.
  • I. Dimitriou. (2013). Performance Analysis of the Discontinuous Reception (DRX) power saving method in 3GPP LTE: A queueing perspective. FORTH-Institute of Computer Science, Herakleion-Greece, 24 January 2013.
  • I. Dimitriou. (2012). Applied probability applications. Department of Mathematical Sciences. University of Essex, 20 March 2012.
  • I. Dimitriou. (2011). Mixed priority retrial queues with negative arrivals. Department of Mathematics, University of Ioannina, Greece,

    Invited visits

  • Inria, MAESTRO Group, Sophia-Antipolis, France. September 4-9, 2016. Host: K. Avrachenkov.
  • TU/e, Stochastics Group, Eindhoven, Netherlands. May 28-June 11, 2017. Host: S. Kapodistria, O. Boxma.

    Grants/scholarships

  • Marie Curie Fellow, ERCIM Alain Bensoussan Fellowship Programme, co-funded by the European Commission under the FP7 Marie-Curie action named ABCDE.
  • Post Doctoral fellowship 'Research Excellence', 1/1/2013-31/12/2013, Aristotle University of Thessalonica Research Commitee, Hosting Department: Department of Mathematics, Scientific Coordinator: Professor George Tsaklidis.
  • Supported from State Scholarships Foundation of Greece (IKY) for MSc and PhD Degree at Mathematics Department, University of Ioannina, Greece (2004-2005, 2006-2008).

    Academic Societies

    EURO Working Group on Stochastic Modelling


    Teaching activities

    Undergradute courses

  • Introduction to Stochastic Processes (2014-,Dept. of Mathematics, Univ. of Patras).
  • Introduction to Queueing Theory (2015-Dept. of Mathematics, Univ. of Patras).
  • Probability theory and Stochastic processes (2014-,Dept. of Material Sciences, Univ. of Patras)
  • Mathematics I (2014-2015, Dept. of Geology, Univ. of Patras)

    Postgradute courses

  • Stochastic Processes (MSc program on "Computer and Decision Mathematics", co-organized with Computer Engineering & Informatics Department)
  • Operations Research (MSc program on "Computer and Decision Mathematics", co-organized with Computer Engineering & Informatics Department)
  • Queueing Systems (MSc program on "Computer and Decision Mathematics", co-organized with Computer Engineering & Informatics Department)

    Students

    Completed MSc students

  • E. Zisimopoulou, (2016). Retrial queueing systems : a review and an application. (MSc Thesis, in Greek, Nemertes DSpace).
  • M. Markou, (2016). On queueing models with impatient customers in random environment : an overview and an application. (MSc Thesis, in Greek, Nemertes DSpace).
  • A. Kaltsas, (2016). Vacation queuing models with applications in energy saving. (MSc Thesis, in Greek, Nemertes DSpace).

    Ongoing MSc students

  • K. Katsanou, (2017). Performance analysis of a cooperative wireless network (ongoing).
  • A. Mantzios, (2017). Queueing models with multiple waiting lines (ongoing).

    Completed BSc students

  • I. Ktorides, (2017). Markovian queueing models with applications to relay-assisted networks.
  • D. Kintos, (2017). Birth-death queueing systems and the method of phases.

    Miscellaneous

    For more information see my pages in Google Scholar, ReaserchGate, Academia, Linkedin