Koutras Vasilis

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Όνομα: 
Vasilis
Επώνυμο: 
Koutras
Βαθμίδα: 
Assistant Professor
Member of Faculty
Area of expertise: 
Stochastic Modeling
Short Curriculum vitae: 

Dr Vasilis Koutras is currently an Assistant Professor at the Department of Financial and Management Engineering. He holds a Bachelor degree in Mathematics (Probability, Statistics & Operational Research)-(2002) from the Department of Mathematics, University of Patras, a Master degree in Mathematical Modeling in Physical Sciences and new Technologies (2004), from the Department of Mathematics, University of the Aegean. He received his PhD diploma from the Department of Financial and Management Engineering, University of the Aegean. He is a member of the Reliability Engineering Laboratory (REL). He is also Academic Staff at the Hellenic Open University, School of Science & Technology, Post Graduate Programme: Quality Management and Technology, Msc, Course:DIP50 Basic Tools and Methods for Quality Control (Ac. Years 2013-14, 2015-16, 2017-18) and Course:DIP61 Special Topics on Quality (Ac. Year 2016-17) . He is teaching Operations Research ΙΙ, Modeling Analysis and Design of Stochastic Systems, Statistics, Stochastic Models, Queuing Theory. He has published over 40 papers in international journals, book chapters and international conferences proceedings (with review procedure). He has also participated as a Researcher in the European Funding Projects:PREPAREDNESS AND PREVENTION PROJECTS IN CIVIL PROTECTION AND MARINE POLLUTION’ – EUROPEAN COMMISION – DG ECHO:An Integrated Methodological framework for Emergency Logistics (MELOGIC), DG Humanitarian and Civil Protection (DG ECHO), ECHO/SUB/2014/695769 and THALES: “Analysis of Supply and Production Systems: an Integrated Approach” (ASPASIA).

Curriculum vitae: 
Μαθήματα που Διδάσκει στο Πρόγραμμα Προπτυχιακών Σπουδών: 
Office: 
A7.2
Address: 
Kountouriotou 41
Telephone: 
2271035468
Ώρες επικοινωνίας: 
Tuesday 15:00-18:00
Wednesday 12:00-15:00
Email: 
v [dot] koutras [at] fme [dot] aegean [dot] gr
Publications: 

 

International Journals

 

1. V.P. Koutras, S. Malefaki, A.N. Platis, Optimization of the dependability and performance measures of a generic model for multi-state deteriorating systems under maintenance, Reliability Engineering & System Safety, Available online 4 January 2017, ISSN 0951-8320, (2017). doi: http://dx.doi.org/10.1016/j.ress. 201701.002.

 

2. C. Salagaras, V. P. Koutras, N.S. Thomaidis, V. Vassiliadis, A.N. Platis, G. Dounias and C. Kyriazis, (2017). Resource Availability Modeling and Optimization in a Car Park Management Problem. International Journal of Operations Research and Information Systems, Special Issue: Operations Research and its Application in Engineering, Vol..8(2), Pages 56-77, (2017) doi:10.4018/IJORIS.2017040103

 

3. A.Manatos, V. P. Koutras and A. N. Platis. Dependability and performance stochastic modelling of a two-unit repairable production system with preventive maintenance, International Journal of Production Research, Vol. 54 (21), Pages. 6395-6415, (2016). doi: 10.1080/00207543.2016.1201603

 

4. V. P. Koutras and A. N. Platis, A. N. User-perceived Availability of a Software Rejuvenation Model with Recovery Time Omission. Quality and Reliability Engineering International, (2015). doi: 10.1002/qre.1862

 

5. V.P. Koutras, S. Malefaki, A.N. Platis. Rejuvenation Effects on the Grid Environment Performance with Response Time Delays using Monte Carlo Simulation, Simulation Modelling Practice and Theory, Vol. 40, Pages 176-191 (2014). doi: http://dx.doi.org/10.1016/j.simpat.2013.10.001

 

6. V.P. Koutras, A. N. Platis, G. A. Gravvanis. Software Rejuvenation and Resource Reservation Policies for Optimizing Server Resource Availability using Cyclic Non-Homogeneous Markov Chains, Applied Stochastic Models in Business and Industry, Vol. 29(1), Pages 61-78 (2014). doi: 10.1002/asmb.945.

 

7. V.P. Koutras, A.N. Platis. Semi-Markov Performance Modeling of a Redundant System with Partial, Full and Failed Rejuvenation, International Journal of Critical Computer Based Systems, Inderscience Publishers, Vol. 1, (1/2/3), Pages 59-85, (2010). doi: 10.1504/IJCCBS.2010.031909

 

8. V.P. Koutras, A.N. Platis, G.A. Gravvanis. Availability and Performance on a Grid Computing Environment with Software Rejuvenation Based on Approximate Inverse Preconditioning. HERMIS: The International Journal of Computer Mathematics and its Applications, Elias A. Lipitakis (Editor-in-Chief), Vol. 11, Pages 69-86, (2010).

 

9. V.P. Koutras, A.N. Platis, G.A. Gravvanis. Optimal Server Resource Reservation Policies for Priority Classes of Users under Cyclic Non-Homogeneous Markov Modeling, European Journal of Operational Research, Vol. 198, Pages 545-556, (2009). doi: http://dx.doi.org/10.1016/j.ejor.2008.09.031

 

10. V.P. Koutras, A.N. Platis, G.A. Gravvanis, Software Rejuvenation for Resource Optimization Based on Explicit Approximate Inverse Preconditioning, Applied Mathematics and Computation, Vol. 189(1), John L. Casti, Melvin Scott (eds.)© 2007, Elsevier, Pages 163-177, (2007). doi: http://dx.doi.org/10.1016/j.amc.2006.11.056

 

11. V.P. Koutras, A. N. Platis, G. A. Gravvanis. On the Optimization of Free Resources Using Non-Homogeneous Markov Chain Software Rejuvenation Model. Reliability Engineering and System Safety, Vol. 92(12), Pages 1724–1732, (2007). doi : http://dx.doi.org/10.1016/j.ress.2006.09.017

 

 

Συνεισφορά σε Βιβλια και Συλλογικούς τόμους

 

12. S. Malefaki, V.P. Koutras, and A.N. Platis. (2017).Optimizing availability and performance of a two-unit redundant multi-state deteriorating system. Recent Advances in Multi-State Reliability, Springer Series in Reliability Engineering, Part of the Springer Series in Reliability Engineering book series (RELIABILITY), Springer, Berlin. Pages 71-105. doi: https://doi.org/10.1007/978-3-319-63423-4_5

 

13. V.P. Koutras. Two-Level Software Rejuvenation Model with Increasing Failure Rate Degradation, Dependable Computer Systems, Advances in Intelligent and Soft Computing Vol. 97, Springer-Verlag Berlin Heidelberg, Pages 101-115, (2011). doi: 10.1007/978-3-642-21393-9_8

 

 

International Conference Proceedings (with review)

 

14. S. Malefaki, V.P. Koutras and A.N. Platis, Multi-State Deteriorating System Dependability with Maintenance using Monte Carlo Simulation. In Proc of SMRLO'16 2016:Second International Symposium on Stochastic Models in Reliability Engineering, Life Science and Operations Management, February 2016, SCE- Shamoon College of Engineering, Beer Sheva, Israel, Pages 61-70, (2016) doi: 10.1109/SMRLO.2016.21

 

15. C.S. Salagaras, V.P. Koutras, A.N. Platis and I.A. Tsokos. Resource Availability Optimization for a Point-to-Point Connection on a Telecommunication Network. In Proc of SMRLO'16 2016:Second International Symposium on Stochastic Models in Reliability Engineering, Life Science and Operations Management, February 2016, SCE- Shamoon College of Engineering, Beer Sheva, Israel, Pages 176-185, (2016). doi: 10.1109/SMRLO.2016.39

 

16. T.V. Tzioutzias, A.N. Platis and V.P. Koutras. Markov Modeling of the Availability of a Wind Turbine Utilizing Failures and Real Weather Data. In Proc of SMRLO'16 2016:Second International Symposium on Stochastic Models in Reliability Engineering, Life Science and Operations Management, February 2016, SCE- Shamoon College of Engineering, Beer Sheva, Israel, Pages 166-196, (2016). doi: 10.1109/SMRLO.2016.40

 

17. I. Stamoulis, A. N. Platis, V. P. Koutras. Planning of electric power distribution networks with reliability criteria. Theory and Engineering of Complex Systems and Dependability, Advances in Intelligent Systems and Computing, Online ISBN 978-3-319-19216-1, W. Zamojski et al. (eds), Springer International Publishing, Volume 365, Pages 455-464 , (2015). doi: 10.1007/978-3-319-19216-1_43.

 

18. S. Malefaki, V.P. Koutras & A.N. Platis, Optimizing the availability and the operational cost of a periodically inspected multi-state deteriorating system with condition based maintenance policies, In Proc of the 9th International Conference on Availability, Reliability and Security, September 2014, University of Fribourg, Switzerland,Fribourg,Switzerland, Pages 403-411, (2014).

 

19. I.G. Sideratos, A. N. Platis, V. P. Koutras, N. Ampazis. Reliability analysis of a two-stage Goel-Okumoto and Yamada S-shaped model, In Proceedings of the Ninth International Conference on Dependability and Complex Systems DepCoS-RELCOMEX. June 30 – July 4, 2014, Brunów, Poland, Advances in Intelligent Systems and Computing, Volume 286, Pages 393-402, (2014).

 

20. T.V. Tzioutzias, A. N. Platis and V. P. Koutras. Modeling the Reliability and the Performance of a Wind Farm Using Cyclic Non-Homogenous Markov Chains. In Proc of Probabilistic Safety Assessment & Management conference (PSAM12), June 2014, United States, Honolulu, Hawaii, (2014).

 

21. P. Diamantopoulos, V.P. Koutras, A.N. Platis. Cloud computing service reliability modeling with batch arrivals and retrial queues, Safety, Reliability and Risk Analysis: Beyond the Horizon-Steenbergen et al (Eds), 2014 Taylor & Francis Group, London, ISBN 978-1-138-00123-7, Pages 2941-2949, (2014).

 

22. A.N. Platis, V.P. Koutras, S. Malefaki. Achieving high availability levels of a deteriorating system by optimizing condition based maintenance policies, Safety, Reliability and Risk Analysis: Beyond the Horizon-Steenbergen et al (Eds), 2014 Taylor & Francis Group, London, ISBN 978-1-138-00123-7, Pages 829-837, (2014).

 

23. V.P. Koutras, A.N. Platis, C.S. Salagaras. Resource Availability Optimization for Green Courier Service, 2013 IFAC Conference on Manufacturing Modeling, Management, and Control (MIM 2013), Pages 1654-1659, (2013).

 

24. N. S. Thomaidis, C.S. Salagaras, V. Vassiliadis, V.P. Koutras, A.N. Platis, G. Dounias. Evolutionary Algorithms for Solving Resource Availability Optimization Problems related to Client Service of Different Priority Classes. In Procs of 2nd International Symposium and 24th National Conference on Operational Research, ISBN: 978-618-80361-1-6, Athens, Greece, September 26-28, (2013), Pages 252-257.

 

25. S. Malefaki, V.P. Koutras, A.N. Platis. Modeling Software Rejuvenation on a Redundant System Using Monte Carlo Simulation, 2012 IEEE 23rd International Symposium on Software Reliability Engineering Workshops (ISSREW), Dallas TX, USA, Pages 277-282, (2012),doi: 10.1109/ISSREW.2012.89.

 

26. V.P. Koutras, A.N. Platis, N. Limnios. Performance Estimation of a System under Minimal, Perfect and Failed Rejuvenation, 11th International Probabilistic Safety Assessment and Management Conference and the Annual European Safety and Reliability Conference 2012 (PSAM11 & ESREL12), Vol. 3, Pages: 1859-1868, (2012).

 

27. V.P. Koutras, A.N. Platis. Applying Partial and Full Rejuvenation in Different Degradation Levels, The 22nd annual International Symposium on Software Reliability Engineering (ISSRE 2010)-3rd Workshop on Software Aging and Rejuvenation (WoSAR 2011), Hiroshima, Japan, Pages 20-25, (2011). doi: 10.1109/WoSAR.2011.14

 

28. V.P. Koutras, S. Malefaki, A.N. Platis. A Monte Carlo Simulation Based Dependability Analysis of a non-Markovian Grid Computing Environment with Software Rejuvenation, Advances in Safety, Reliability and Risk Management - Proceedings of the European Safety and Reliability Conference, ESREL 2011, Pages: 1959-1966, (2011), doi: 10.1201/b11433-276.

 

29. E.C. Grigoriadou, V.P. Koutras, A. Platis. Semi-Markov coverage modeling and optimal maintenance policies of an automated restoration mechanism, Advances in Safety, Reliability and Risk Management - Proceedings of the European Safety and Reliability Conference, ESREL 2011, Pages: 949-956, (2011), doi: 10.1201/b11433-133.

 

30. A.N. Platis, V.P. Koutras, Software Rejuvenation on a PKI Infrastructure, The 21st annual International Symposium on Software Reliability Engineering (ISSRE 2010)-2nd Workshop on Software Aging and Rejuvenation (WoSAR 2010), San Jose, USA, November 1 – 4, IEEE Xplorer, in press, (2010), doi:: 10.1109/WOSAR.2010.5722102.

 

31. V.P. Koutras, A.N. Platis, N. Limnios. Dependability Measures Maximum Likelihood Estimation for a Redundant System with Minimal, Perfect and Failed Rejuvenation, Proceedings of European Safety and Reliability Conference, ESREL 2010, Pages. 1553-1560, (2010).

 

32. V.P. Koutras, C.S. Salagaras, A.N. Platis. Software Rejuvenation for Higher Levels of VoIP Availability and Mean Time To Failure, 4th International Conference on Dependability of Computer Systems (DepCoS-RELCOMEX '09), © 2009, IEEE Computer Society Press, Pages 99-106, (2009), doi: http://doi.ieeecomputersociety.org/10.1109/DepCoS-RELCOMEX.2009.21.

 

33. V.P. Koutras, A.N. Platis. Modeling Resource Availability and Optimal Fee for Priority Classes in a Website, Proceedings of European Safety and Reliability Conference (ESREL 2009), Pages 1191-1198, (2009).

 

34. J.B. Violentis, A.N. Platis, G.A. Gravvanis, V.P. Koutras. Electrical Substation Efficient Maintenance Policies Based On Semi-Markov Modeling and Approximate Inverse Preconditioning, Proceedings of The 9th Hellenic European Research on Computer Mathematics & its Applications Conference (HERCMA 2009), (2009).

 

35. P.K. Saravakos, G.A. Gravvanis, V.P. Koutras, A.N. Platis. A Comprehensive Approach to Software Aging and Rejuvenation on a Single Node Software System, Proceedings of The 9th Hellenic European Research on Computer Mathematics & its Applications Conference (HERCMA 2009), (2009).

 

36. V.P. Koutras, A.N. Platis, N. Limnios. Availability and Reliability Estimation for a System Undergoing Minimal, Perfect and Failed Rejuvenation, First International Workshop on Software Aging and Rejuvenation WOSAR 2008 in conjunction with 19th IEEE International Symposium on Software Reliability Engineering ISSRE 2008, IEEE Xplorer, Pages 1-6, (2008), doi: 10.1109/ISSREW.2008.5355519.

 

37. V.P. Koutras, A.N. Platis. Guaranteed Resource Availability in a Website, Safety, Reliability and Risk Analysis: Theory, Methods and Applications – Martorell et al. (eds), © 2008 Taylor & Francis Group, London, Pages 1525-1532, (2008).

 

38. V.P. Koutras, A.N. Platis. Modeling Perfect and Minimal Rejuvenation for Client Server Systems with Heterogeneous Load, 14th IEEE Pacific Rim International Symposium on Dependable Computing, IEEE Computer Society Press, Pages 95-103, (2008), doi: 10.1109/PRDC.2008.22, .

 

39. V.P. Koutras, A.N. Platis. Semi-Markov Availability Modeling of a Redundant System with Partial and Full Rejuvenation Actions, 3rd International Conference on Dependability of Computer Systems (DepCoS-RELCOMEX '08), © 2008, IEEE Computer Society Press, Pages 127-134, (2008) doi: 10.1109/DepCoS-RELCOMEX.2008.13 .

 

40. V.P. Koutras, A.N. Platis, G. A. Gravvanis. Software Rejuvenation on a Grid Computing Environment for Higher Availability Based on Approximate Inverse Preconditioning, Proceedings of The 8th Hellenic European Research on Computer Mathematics & its Applications Conference (HERCMA 2007), (2007).

 

41. J.B. Violentis, V.P. Koutras, A.N. Platis. G.A. Gravvanis. Asymptotic Availability of an Electrical Substation via a Semi-Markov Process Computed by Generalized Approximate Inverse Preconditioning, Proceedings of The 8th Hellenic European Research on Computer Mathematics & its Applications Conference (HERCMA 2007), (2007).

 

42. V.P. Koutras, A.N. Platis. VoIP Availability and Service Reliability through Software Rejuvenation Policies, 2nd International Conference on Dependability of Computer Systems (DepCoS-RELCOMEX '07), © 2007, IEEE Computer Society Press, Pages 262-269, (2007), doi: 10.1109/DEPCOS-RELCOMEX.2007.54 .

 

43. V.P. Koutras, A.N. Platis, G. A. Gravvanis. Software Rejuvenation for Higher Levels of Grid Availability. Risk, Reliability and Societal Safety – Aven & Vinnem (eds), © 2007 Taylor & Francis Group, London, Pages 1723-1730, (2007).

 

44. V.P. Koutras, A.N. Platis. Resource Availability Optimization for Priority Classes in a Website, 12th IEEE International Symposium on Pacific Rim Dependable Computing(PRDC ’06), Jeske, Giardo, Dai (eds)© 2006, IEEE Computer Society Press, Los Alamitos, California, Pages 305-312, (2006), doi: 10.1109/PRDC.2006.54 .

 

45. V.P. Koutras, A.N. Platis. Applying software rejuvenation in a two node cluster system for high availability, International Conference on Dependability of Computer Systems (DEPCOS-RELCOMEX'06), (ed.)© 2006, IEEE Computer Society Press, , Pages 175-182, (2006), doi: 10.1109/DEPCOS-RELCOMEX.2006.7.

 

46. V.P. Koutras, A.N. Platis. Optimal Rejuvenation Policy for Increasing VoIP Service Reliability, Advances in Safety and Reliability, Soares (ed.)© 2006 Taylor & Francis Group, London, Vol. 3, Pages 2285-2290, (2006).

 

47. V.P. Koutras, A. Platis. Optimizing the Amount of Free Resources on a Computer System using Software Rejuvenation, Advances in Safety and Reliability, Kołowrocki (ed.), © 2005 Taylor & Francis Group, London, Pages 1187-1192, (2005).

 

48. V.P. Koutras, E. Mennis, N. Nikitakos, A.N. Platis. Software rejuvenation in maritime applications, Advances in Safety and Reliability Kołowrocki (ed.)© 2005 Taylor & Francis Group, London, Pages 1193-1197, (2005).

 

 

Conference Presentations (Book of Abstracts)

 

49. S. Malefaki, V.P. Koutras and A.N. Platis. (2017). Sojourn time distributions effects on a redundant multi-state deteriorating system with maintenance. European Meeting of Statisticians (EMS), 24-28 July 2017, Helsinki, Finland.

 

50. A.Manatos, S. Malefaki, V.P. Koutras.. Modeling and Optimization of Dependability and Performance Measures of Multi-State Deteriorating Systems with Redundancy, 29th Panhellenic Statistics Conference, (2016). (in greek)

 

51. S. Malefaki, V. P. Koutras, A.N. Platis. Optimization of Maintennace Policies for Technological Systems, 28th Panhellenic Statistics Conference, (2015). (in greek)

 

52. V. Vassiliadis, C. Salagaras, V. Koutras, N. Thomaidis, A. Platis, G. Dounias, C. Kyriazis. Resource availability modeling and optimization in a car park management problem, 3rd International Symposium & 25th National Conference on Operational Research, Volos, Greece, 26-28 June 2014.

 

53. V.P. Koutras, S. Malefaki, A. N. Platis. Dependability Analysis of a Software Rejuvenation Model Based on Monte Carlo Simulation, 24ο Panhellenic Statistics Conference, (2011).

 

54. S. Malefaki, V.P. Koutras, A.N. Platis. Optimal Maintenance Policies for Technological Systems, , 28th Panhellenic Statistics Conference, (2015). (in greek)

 

 

Submitted Work:

 

55. E. Baou, V.P. Koutras, V. Zeimpekis, I. Minis (2017). Emergency evacuation planning in natural disasters under diverse population and fleet characteristics.

 

 

Ερευνητικά ενδιαφέροντα: 

Stochastic modeling of highly available and reliable systems. Stochastic modeling of software rejuvenation, computer systems performability indicators, software reliability, Markov and Semi-Markov processes, preventive maintenance, operations research.

 

 

Doctoral
Θέμα: 
Optimizing Performance and Dependability of Computer Systems: Software Rejuvenation Stochastic Modeling
Επιβλέπων: 
Year of completion: 
2010