## Scientific Journals Publications and Thesis

**PHD THESIS**- Optimal control of non-linear parabolic partial differential equations; Theory and numerical analysis, National Technical University of Athens, 1994.

**MSC THESIS**- A system of Algorithms for the Mathematical Solution to the problem of natural systems oscilaltion with (n) degrees of freedom, National and Kapodistrian University of Athens, 1983

**PUBLICATIONS IN PEER REVIEWED SCIENTIFIC JOURNALS**

- Eisa A. Al-Said, M. A. Noor, Anwar H. Almualim, B. Kokkinis, J. Coletsos, Quartic spline method for solving second-order boundary value problems, Int. Journal of the Physical Sciences, Vol. 6(17), PP. 4208-4212, 2011.
- Muhammad Aslam Noor, Khalida Inayat Noor, M. Rafiq, Eisa Said, J. Coletsos, Homotopy perturbation method for solving a system of third-order boundary value problems, Int. Journal of the Physical Sciences, Vol. 6(16), PP. 4128-4133, 2011. Classical and relaxed Optimization Methods for Optimal Control Problems, με Chryssovergi I, Kokkinis B., Int. Math. Forum 2. No. 29-32, pp. 1477-1498, 2007.
- I. Chryssovergis, J. Coletsos, J. Geiser, B. Kokkinis, Discretization-Optimization Methods for Nonlinear Elliptic Relaxed Optimal Control Problems with State Constraints, Institute of Mathematics, Humboldt University, Berlin, 2006.
- I. Chryssovergis, J. Coletsos, B. Kokkinis, Discretization Methods for Optimal Control Problems with State Constraints, J. Comput. Appl. Math., No. 1, pp. 1-31, 2006.Optimization Methods for Nonlinear Elliptic Optimal Control Problems with State Constraints, με Kokkinis B., WSEAS Transactions on Mathematics, ISSUE 11, Vol. 5, pp. 1169-1176, Nov 2006.
- I. Chryssovergis, J. Coletsos, J. Geiser, B. Kokkinis, Discretization-Optimization Methods for Nonlinear Parabolic Relaxed Optimal Control Problems with State Constraints, Humboldt University, Berlin, 2006.
- I. Chryssovergis, J. Coletsos, B. Kokkinis, Discretization Methods for Nonconvex Optimal Control Problems with State Constraints, J. Numer. Funct. Anal. Optim., Vol. 26, No. 3, pp. 321-348, 2005.
- I. Chryssovergis, J. Coletsos, B. Kokkinis, Approximate Gradient Projection Method with Runge-Kutta Schemes for Optimal Control Problems, Comp. Optim. Appl., Vol. 29, No. 1, pp. 91-115, 2004.
- I. Chryssovergis, J. Coletsos, B. Kokkinis, Approximate Relaxed Descent Method for Optimal Control Problems, Control & Cybernetics, Vol. 30, No. 4, pp. 385-404, 2001.
- I. Chryssovergis, J. Coletsos, B. Kokkinis, Discrete Relaxed Method for Semilinear Parabolic Optimal Control Problems, Control & Cybernetics, Vol. 28, No. 2, pp. 157-176, 1999.
- I. Chryssovergis, A. Bacopoulos, J. Coletsos, B. Kokkinis, Discrete Approximation of Nonconvex Hyperbolic Optimal Control Problems with State Constraints, Control & Cybernetics, Vol. 27, No. 1, pp. 29-50, 1998.
- I. Chryssovergis, A. Bacopoulos, B. Kokkinis, J. Coletsos, Mixed Frank-Wolfe Penalty Method with Applications to Nonconvex Optimal Control Problems, Journal of Optimization Theory and Applications (JOTA), Vol. 94, No2, pp. 311-334, 1997.

**PUBLICATIONS IN PEER REVIEWED INTERNATIONAL SCIENTIFIC CONFERENCE PROCEEDINGS**

- J. Coletsos, C. Ntakolia, Air Traffic Management: The free flight concept (Lower Level), 3rd International Symposium and 25th National Conference on Operational Research in Transportation, Energy and the Environment, Hellenic Operational Society (HELORS) and The University of Thessaly, Volos, June 26-28, 2014.
- J. Coletsos, C. Ntakolia, Operations research on Air Traffic Management (ATM) of the future, HOBA 2014 International Conference, Hellenic Open University, Athens, March 8-9, 2014.
- J. Coletsos, B. Kokkinis, Optimal Control of Nonlinear Elliptic PDEs – Theory and Optimization Methods, 9th International Conference, Large-Scale Scientific Computing, LSSC 2013, Sozopol Bulgaria, June 3-7, 2013.
- I. Chryssoverghi, J. Coletsos, B. Kokkinis, Lirkov, Ivan (Editor) Et. Al., Classical and Relaxed Progressively Refining Discretization-Optimization Methods for Optimal Control Problems Defined by Ordinary Differential Equations, 8th International Conference, Large-Scale Scientific Computing, LSSC 2011, Sozopol Bulgaria, June 6-10, 2011, Revised Selected Papers, Berlin: Springer, Lecture Notes In Computer Science 7116, Pp. 106-114, 2012.
- I. Chryssoverghi, J. Coletsos, B. Kokkinis, Lirkov, Ivan (Editor) Et. Al., Classical and Relaxed Optimization Methods for Non Linear Parabolic Optimal Control Problems, 7th International Conference, Large-Scale Scientific Computing, LSSC 2009, Sozopol Bulgaria, June 4-8, 2009, Revised Papers, Berlin: Springer, Lecture Notes In Computer Science 5910, Pp. 247-255, 2010.
- J. Coletsos, A. Anagnostopoulou, Business plan optimization using decision making theory, 21st National Conference of Hellenic Company of Operational Research, Decision making in health systems, Athens, 2009.
- J. Coletsos, Discretization-Optimization Methods for Relaxed Optimal Control Problems, 7th International Workshop on Mathematical Methods in Scattering Theory and Biomedical Engineering, Numphaio, Greece, 2005.
- I. Chryssovergis, J. Coletsos, B. Kokkinis, Classical and Relaxed Discretization Methods for Semilinear Parabolic Optimal Control Problems, Panhellenic Conference on Mathematical Analysis and Applications, NTUA, Athens, 2004.
- I. Chryssovergis, J. Coletsos, B. Kokkinis, Progressively Refining Discrete Methods for Constrained Optimal Control Problems, 4th GRACM Congress on Computational Mechanics, Patra, 2002 (Invitation).
- J. Coletsos, Mixed Gradient Penalty Method for Optimal Control Problems defined by Semilinear Parabolic Equations, Proceedings of 5th Hellenic-European Conference on Computer Mathematics and its Applications HERCMA 2001.
- J. Coletsos, I. Chryssovergis, B. Kokkinis, Approximation of Nonconvex Semilinear Hyperbolic Optimal Control Problems, Proceedings of the Third Hellenic-European Conference on Mathematics and Informatics Hermis 96, Athens, University of Economics and Business, pp. 238-245, 1996.
- J. Coletsos, I. Chryssovergis, Approximation of Nonlinear Boundary Parabolic Optimal Control Problems, Proceedings of the First Hellenic-European Conference on Mathematics and Informatics Hermis 92, Athens, University of Economics and Business, pp. 63-67, 1992.