**Advances in Computing**

Advances in Computing deals with the theoretical foundations of information and computation and their implementation and application in computer systems. It publishes regular papers and special issues on specific topics of interest to international audiences of educational researchers.

**p-ISSN:**2163-2944**e-ISSN:**2163-2979**Website:**http://journal.sapub.org/ac

## George Gravvanis

**Editor-in-Chief of**

*Advances in Computing*Associate Professor, Department of Electrical and Computer Engineering, Greece

**Research Areas**

Computational Methods-Mathematical Modelling and Applications, Parallel Computations-Design of Parallel Algorithmic Methods, Mathematics of Computing-Numerical Algorithms-Mathematical Software and Sparse Matrix Technology and Numerical Solution of Partial

### Education

1992 | Ph.D | Department of Applied Informatics, Athens University of Economics and Business |

1984 | Master of Science | Department of Mathematics, Brunel University |

1982 | Bachelor of Science | Department of Mathematics, University of Salford, Manchester, U.K. |

### Experience

2010-present | Associate Professor, Department of Electrical and Computer EngineeringSchool of Engineering, Democritus University of Thrace |

2004-2010 | Assistant Professor, Department of Electrical and Computer Engineering, School of Engineering, Democritus University of Thrace |

2001-2003 | Associate Professor, Department of Information and Communication Systems Engineering, University of the Aegean |

2001-2002 | Associate Professor, Department of Mathematics, University of the Aegean |

1999-2000 | Associate Professor, Department of Informatics, Athens University of Economics and Business |

1996-1997, 1997-1998 | Associate Professor, Department of Electronics and Computer Engineering, Technical University of Crete |

1996-1997, 1997-1998 | Adjunct Professor, Nursing Military Academy |

1992-1993, 1993-1994, 1994-1995 | Adjunct Professor, Air-Force Academy |

1987-1990, 1992-1993 | Lecturer, Department of Computer Science and Computer Engineering, La Verne College, Athens Campus, of University of La Verne, California |

2004 | Ministry of Employment and Social Protection |

1995-2004 | Ministry of Labor and Social Security |

1993-1995 | Ministry of Health, Welfare and Social Security |

### Publications: Journals

[1] | Guest Editor: G.A. Gravvanis, Special Issue on "Aspects of Numerical Algorithms, Parallelization and Applications, Journal of Computational and Applied Mathematics, vol. 236(3), 2011, pp.279-411. |

[2] | Guest Editors: G.A. Gravvanis, J. Morrison and Heinz Stockinger, Special Section on "Defining the Grid, Experiences and Future Trends", Future Generation Computer Systems: The International Journal of Grid Computing: Theory, Methods and Applications, vol. 25(4), 2009, pp. 399-443, ISSN: 0167-739X. |

[3] | Guest Editors: G.A. Gravvanis, J. Morrison and G.C. Fox, Special Issue on Grid Technology, The Journal of Supercomputing, vol. 42(1), 2007, pp. 1-144, ISSN: 0167-739X. |

[4] | Guest Editors: G.A. Gravvanis, J. Morrison and H.R. Arabnia, Special Section on Grid Technology and Applications, Future Generation Computer Systems, The International Journal of Grid Computing: Theory, Methods and Applications, vol. 23(4), 2007, pp. 523-670, ISSN: 0167-739X. |

[5] | Guest Editors: E.A. Lipitakis, I.C. Demetriou, M.P. Bekakos, K. Margaritis, I.Z. Milovanovic, G.A. Gravvanis and A. Tassopoulos, Special Issue in memory of Professor D.J. Evans, Journal of Neural Parallel and Scientific Computations, vol. 14(2/3), 2006, pp.135-336, ISSN: 1061-5369. |

[6] | Guest Editors: G.A. Gravvanis and H.R. Arabnia, Special Section on Parallel and Distributed Algorithms and Systems, The Journal of Future Generation Computer Systems, vol. 22(1-2), 2006, pp. 32-101 ISSN: 0167-739X. (The 2003 International Conference on Parallel and Distributed Processing Techniques and Applications, June 23-26, 2003 Monte Carlo Resort, Las Vegas, Nevada, USA) |

[7] | Guest Editors: G.A. Gravvanis and H.R. Arabnia, Special Issue on Parallel and Scientific Computations with Applications, Journal of Mathematical Modelling and Algorithms, vol. 4 No 1, 2005, pp.1-128, ISSN: 1570-1166. (The 2003 International Conference on Parallel and Distributed Processing Techniques and Applications, June 23-26, 2003 Monte Carlo Resort, Las Vegas, Nevada, USA). |

[8] | Guest Editors: G.A. Gravvanis and H.R. Arabnia, Special Issue on Parallel and Distributed Algorithms, The Journal of Parallel Algorithms and Applications, vol. 19(2-3), 2004, pp. 77-193, ISSN: 1063-7192. (The 2003 International Conference on Parallel and Distributed Processing Techniques and Applications, June 23-26, 2003 Monte Carlo Resort, Las Vegas, Nevada, USA). |

[9] | Guest Editors: H.R. Arabnia, G.A. Gravvanis and M.P. Bekakos, Special Issue on Grid Computing, Journal of Neural Parallel and Scientific Computations, vol. 12(3), 2004, pp.261-454, ISSN: 1061-5369. (The 2003 International Conference on Parallel and Distributed Processing Techniques and Applications, The 2003 International Conference on Web Services and The 2003 International Conference on Internet Computing, June 23-26, 2003 Monte Carlo Resort, Las Vegas, Nevada, USA). |

[10] | Guest Editors: G.A. Gravvanis and R.W. Lewis, Special Issue Preconditioning Methods: Algorithms, Applications and Software Environments, International Journal of Computers and Structures, vol. 82(28), 2004, pp. 2361-2451, ISSN: 0045-7949, Pergamon (Elsevier), Second MIT Conference on Computational Fluid and Solid Mechanics, June 17-20, 2003, Boston, USA. |

[11] | Guest Editors G.A. Gravvanis and E.E. Santos, Special Issue on Parallel and Distributed Processing and Applications, The Journal of Supercomputing vol. 30(2), 2004, pp. 75-198, ISSN: 0920-8542. (The 2002 International Conference on Parallel and Distributed Processing Techniques and Applications, June 24-27, 2002 Monte Carlo Resort, Las Vegas, Nevada, USA). |

[12] | Guest Editors: G.A. Gravvanis and H.R. Arabnia, Special Issue on Computational Science and Applications, Journal of Mathematical Modelling and Algorithms, vol. 2(3), 2003, pp.183-294, ISSN: 1570-1166. (The 2002 International Conference on Parallel and Distributed Processing Techniques and Applications, June 24-27, 2002 Monte Carlo Resort, Las Vegas, Nevada, USA) |

[13] | Guest Editor G.A. Gravvanis, Special Issue on Computational Sciences and Scientific Computing, The Journal of Supercomputing, vol. 25(2), 2003, pp. 107-190, ISSN: 0920-8542. (The 2001 International Conference on Parallel and Distributed Processing Techniques and Applications, June 25-28, 2001 Monte Carlo Resort, Las Vegas, Nevada, USA) |

[14] | Guest Editor G.A. Gravvanis, Special Issue on Numerical Computations and Methods, Journal of Mathematical Modelling and Algorithms, vol. 1(3), 2002, pp. 151-241, ISSN: 1570-1166. (The 2001 International Conference on Parallel and Distributed Processing Techniques and Applications, June 25-28, 2001 Monte Carlo Resort, Las Vegas, Nevada, USA) |

[15] | Invited Co-Editor, International Journal of Differential Equations and Applications, vol. 5(2), 2002, pp. 113-212, ISSN: 1311-2872, eds. George Gravvanis, Dimitar Kolev and Svetoslav Nenov, Academic Publications, Invited Lectures, 12th International Colloquium on Differential Equations, 18-23 August 2001, Plovdiv, Bulgaria |

[16] | Gravvanis G.A., Matskanidis P., Giannoutakis K.M. and Lipitakis E.A. (2011): On the POSIX threads based parallelism for Finite Element approximate inverses on multicore systems, Engineering Computations, to appear |

[17] | Filelis-Papadopoulos C.K., Gravvanis G.A., Matskanidis P.I. and Giannoutakis K.M. (2011): On the GPGPU parallelization issues of finite element approximate inverse preconditioning, Journal of Computational and Applied Mathematics 236(3), 294-307 |

[18] | Kehagias D.D., Giannoutakis K.M., Gravvanis G.A. and Tzovaras D. (2011): An ontology-based mechanism for automatic categorization of web services, Concurrency and Computation: Practice and Experience, to appear |

[19] | Gravvanis G.A., Filelis-Papadopoulos C.K. and Giannoutakis K.M. (2011): Solving finite difference linear systems on GPUs: CUDA based Parallel Explicit Preconditioned Biconjugate Conjugate Gradient type Methods, Journal of Supercomputing, to appear |

[20] | Gravvanis G.A., Giannoutakis K.M. (2011): Finite element approximate inverse preconditioning for solving 3D biharmonic problems on shared memory systems, Computer Modeling in Engineering and Sciences (CMES) 71(4), 305-330 |

[21] | Koutras V.P., Platis A.N., Gravvanis G.A. (2010): Availability and performance on a grid computing environment with software rejuvenation based on approximate inverse preconditioning, HERMIS: An International Journal of Computer Mathematics and its Applications 11, (ISSN 1108-7609), http://www.aueb.gr/pympe/hermis/hermis-volume-11/HERMIS-VOL-11-PAPERS/KOUTRAS-PLATIS-GRAVVANIS_HERMIS-Journal_26_11_09.pdf |

[22] | Gravvanis G.A. (2009): High Performance Inverse Preconditioning, Archives of Computational Methods in Engineering 16(1), 77-108 |

[23] | Koutras V.P., Platis A.N. and Gravvanis G.A. (2009): Optimal server resource reservation policies for priority classes of users under cyclic non-homogeneous Markov Modeling, European Journal of Operational Research 198(2), 545-556 |

[24] | Gravvanis G.A., Giannoutakis K.M. (2008): Fast parallel finite element approximate inverses, Computer Modeling in Engineering and Sciences (CMES) 32(1), 35-44 |

[25] | Violentis J.B., Platis A.N., Gravvanis G.A. and Lipitakis E.A. (2008): Performance analysis of an electrical substation via a semi-markov process computed by generalized approximate inverse preconditioning, HERMIS: An International Journal of Computer Mathematics and its Applications 10, 33-46, (ISSN 1108-7609); http://www.aueb.gr/pympe/hermis/hermis-volume-10/HERMIS-VOL-10-PAPERS/VIOLENTIS-PLATIS-GRAVVANIS-LIPITAKIS-1.pdf |

[26] | Gravvanis G.A. (2009): OpenMP based parallel normalized direct methods for sparse finite element linear systems, The Journal of Supercomputing, 47(1), 44-52. |

[27] | Giannoutakis K.M., Gravvanis G.A. (2009): Design and implementation of parallel approximate inverse classes using OpenMP, Concurrency and Computation: Practice and Experience (CCPE), 21(2), 115-131 |

[28] | Giannoutakis K.M., Gravvanis G.A. (2008): High performance finite element approximate inverse preconditioning, Applied Mathematics and Computation (AMC), 201(1-2), 293-304 |

[29] | Gravvanis G.A. and Epitropou V.N. (2008): Java multithreading based parallel approximate arrow-type inverses, Concurrency and Computation: Practice and Experience (CCPE) 20(10), 1151-1172; available online 2007 |

[30] | Gravvanis G.A., Epitropou V.N. and Giannoutakis K.M. (2007): On the performance of parallel approximate inverse preconditioning using Java multithreading techniques, Applied Mathematics and Computation (AMC) 190, 255-270. |

[31] | Giannoutakis K.M., Gravvanis G.A., Clayton B., Patil A., Enright T. and Morrison J.P. (2007): Matching high performance approximate inverse preconditioning to architectural platforms, The Journal of Supercomputing, 42(2), 145-163. |

[32] | Koutras V.P., Platis A.N., Gravvanis G.A. (2007): Software rejuvenation for resource optimization based on explicit approximate inverse preconditioning, Applied Mathematics and Computation (AMC), 189(1), 163-177. |

[33] | Gravvanis G.A., Giannoutakis K.M. (2006): Distributed finite element normalized approximate inverse preconditioning, Computer Modeling in Engineering and Sciences (CMES), 16(2), 69-82 |

[34] | Koutras V.P., Platis A.N., Gravvanis G.A. (2007): On the optimization of free resources using non-homogeneous markov chains software rejuvenation model, Reliability Engineering and System Safety (RESS) 92, 1724-1732; available online 2006 |

[35] | Gravvanis G.A., Giannoutakis K.M., Lipitakis E.A. (2006): On the numerical solution of singularly perturbed non-linear parabolic and elliptic partial differential equations, HERMIS: An International Journal of Computer Mathematics and its Applications 8, 40-60, (ISSN 1108-7609); http://www.aueb.gr/pympe/hermis/hermis-volume-8/ |

[36] | Giannoutakis K.M., Gravvanis G.A. (2006): Fast normalized explicit approximate inverse preconditioning for solving linear and non-linear finite element systems, Journal of Neural Parallel and Scientific Computations 14 (2/3), 205-224, in memory of Prof. D.J. Evans |

[37] | Gravvanis G.A. (2006): Parallel inverse arrowhead matrix algorithms on symmetric multiprocessor systems, Journal of Neural Parallel and Scientific Computations 14 (2/3), 291-308, in memory of Prof. D.J. Evans |

[38] | Giannoutakis K.M., Gravvanis G.A. and Bekakos M.P. (2005): High performance computations using the internet and grid technology, Journal of Neural Parallel and Scientific Computations 13, 459-478 |

[39] | Giannoutakis K.M. and Gravvanis G.A. (2005): A performance study of normalized explicit finite element approximate inverse preconditioning on uniprocessor and multicomputer systems, Engineering Computations (Inter. J. for Computer-Aided Engineering and Software) 23(3), 192-217. |

[40] | Gravvanis G.A., Giannoutakis K.M. (2005): Normalized Explicit Approximate Inverse Preconditioning for solving 3D boundary value problems on uniprocessor and distributed systems, Int. J. Numerical Methods in Engineering 65(1), 84-110 |

[41] | Gravvanis G.A., Giannoutakis K.M. (2005): Parallel preconditioned conjugate gradient square method based on normalized approximate inverses, Journal of Scientific Programming 13(2), 79-91. |

[42] | Gravvanis G.A., Giannoutakis K.M., Missirlis N. (2004): A distributed preconditioned conjugate gradient method, Parallel Algorithms and Applications 19(2-3), 163-174 |

[43] | Gravvanis G.A., Giannoutakis K.M. (2004): Normalized explicit finite element approximate inverse preconditioning, International Journal of Computers and Structures 82(28), 2377-2388, Pergamon (Elsevier) |

[44] | Gravvanis G.A., Giannoutakis K.M. (2004): On the rate of convergence and computational complexity of normalized implicit preconditioning for solving finite difference equations in three space variables, Inter. J. of Computational Methods 1(2), 367-386. Invited paper in Special Issue of I. J.Comp. Meth. dedicated to Prof. S. Valliapan |

[45] | Gravvanis G.A., Giannoutakis K.M., Bekakos M.P., Efremides O.B. (2004): Parallel and systolic solution of normalized explicit approximate inverse preconditioning, The Journal of Supercomputing 30(2), 77-96. |

[46] | Maglogiannis I., Zafiropoulos I., Platis A., Gravvanis G.A. (2004): Computing the success factors in consistent acquisition and recognition of objects in color digital images by explicit preconditioning, The Journal of Supercomputing 30(2), 179-198. |

[47] | Platis A.N., Gravvanis G.A., Giannoutakis K.M., Lipitakis E.A. (2003): A two-phase cyclic non-homogeneous markov chain performability evaluation by explicit approximate inverses applied to a replicated database system, Journal Mathematical Modelling and Algorithms 2(3), 235-249. |

[48] | Gravvanis G.A. (2003): Explicit preconditioned domain decomposition schemes for solving non-linear boundary value problems, Special Issue on Numerical Methods in Physics, Chemistry and Engineering, Inter. Jour. Comp. & Math. with Applications 45, 263-272. |

[49] | Gravvanis G.A., Giannoutakis K. (2003): Normalized Explicit Finite Element Approximate Inverses, I. J. Differential Equations and Applications 6(3), 253-267. Invited one-hour lecture, 13th International Colloquium on Differential Equations, 18-23 August 2002, Plovdiv, Bulgaria. |

[50] | Gravvanis G.A., Platis A.N. (2003): On the computation of asymptotic availability of cyclic non-homogeneous Markov chains systems by approximate inverse preconditioning, I. J. Computational and Numerical Analysis and Applications 3(1), 27-39. Invited one-hour lecture, 11th International Colloquium on Numerical Analysis and Computer Science with Applications, 12-17 August 2002, Plovdiv, Bulgaria. |

[51] | Platis A.N., Gravvanis G.A. (2003): Modeling the dependability of a class partitioned system and using explicit approximate arrow-structure inverses, I. J. Computational and Numerical Analysis and Applications 3(1), 41-54. Invited one-hour lecture, 11th International Colloquium on Numerical Analysis and Computer Science with Applications, 12-17 August 2002, Plovdiv, Bulgaria. |

[52] | Gravvanis G.A. (2003): On the solution of boundary value problems by using fast generalized approximate inverse banded matrix techniques, Special Issue of The Journal of Supercomputing , 25(2), 119-129. |

[53] | Gravvanis G.A. (2002): Domain decomposition-finite difference approximate inverse preconditioned schemes for solving fourth order equations, Special Issue of the Journal Mathematical Modelling and Algorithms 1(3), 181-192 |

[54] | Gravvanis G.A. (2002): Solving symmetric arrowhead and special tridiagonal linear systems by fast approximate inverse preconditioning, Journal Mathematical Modelling and Algorithms 1(4), 269-282. |

[55] | Gravvanis G.A. (2002): Explicit Approximate Inverse Preconditioning Techniques, Archives of Computational Methods in Engineering 9(4), 371-402. |

[56] | Gravvanis G.A. (2002): Explicit preconditioned domain decomposition schemes, I. J. Computational and Numerical Analysis and Applications 2(1), 19-36. Invited one hour lecture for the 10th International Colloquium on Numerical Analysis and Computer Science with Applications, 12-17 August 2001, Plovdiv, Bulgaria |

[57] | Gravvanis G.A. (2002): Solving special type matrices by explicit approximate inverse preconditioning, I. J. Computational and Numerical Analysis and Applications 2(1), 37-53. |

[58] | Platis A.N., Gravvanis G.A. (2002): Dependability evaluation using explicit approximate inverse preconditioning, I. J. Computational and Numerical Analysis and Applications 2(1), 71-86. |

[59] | Gravvanis G.A. (2002): Solving symmetric arrow-type linear systems by explicit preconditioned schemes, I. J. Differential Equations and Applications 5(4), 325-338. |

[60] | Gravvanis G.A. (2001): The convergence rate and complexity of explicit preconditioned conjugate gradient methods based on approximate inverse banded matrix techniques, Journal of Neural Parallel and Scientific Computations 9(3 and 4), 355-367 |

[61] | Gravvanis G.A. (2001): A fast explicit preconditioned symmetric finite element scheme, Journal of Neural Parallel and Scientific Computations 9(1), 59-66. |

[62] | Gravvanis G.A. (2001): Explicit Approximate Inverse Matrix Techniques, I. J. Differential Equations and Applications 3(3), 285-300. Invited one-hour lecture for the 9th Intern. Colloquium on Numerical Analysis and Computer Science with Applications, 12-17 August 2000, Plovdiv, Bulgaria |

[63] | Gravvanis G.A. (2001): Explicit preconditioned conjugate gradient methods for solving banded matrices, I. J. Differential Equations and Applications 3(4), 409-425. Invited one-hour lecture for the 11th Intern. Colloquium on Differential Equations, 18-23 August 2000, Plovdiv, Bulgaria |

[64] | Gravvanis G.A. (2000): Explicit preconditioned generalized domain decomposition methods, I. J. Applied Mathematics 4(1), 57-71 |

[65] | Gravvanis G.A. (2000): Fast explicit approximate inverses for solving linear and non-linear finite difference equations, I. J. Differential Equations and Applications 1(4), 451-473 |

[66] | Gravvanis G.A. (2000): Generalized approximate inverse preconditioning for solving non-linear elliptic boundary-value problems, I. J. Applied Mathematics 2(11), 1363-1378 |

[67] | Gravvanis G.A. (2000): Domain decomposition approximate inverse matrix techniques, I. J. Differential Equations and Applications 1(3), 323-334 |

[68] | Gravvanis G.A. (2000): Explicit preconditioning conjugate gradient schemes for solving biharmonic equations, Engineering Computations (Inter. J. for Computer-Aided Engineering and Software) 17(2), 154-165. |

[69] | Gravvanis G.A. (2000): Explicit isomorphic iterative methods for solving arrow-type linear systems, Inter. J. Comp. Math. 74(2), 195-206. |

[70] | Gravvanis G.A. (1999): Generalized approximate inverse finite element matrix techniques, Journal of Neural Parallel and Scientific Computations 7(4), 487-500. |

[71] | Gravvanis G.A. (1999): Preconditioned iterative methods for solving 3D boundary value problems, Inter. J. Comp. Math. 71, 117-136. |

[72] | Gravvanis G.A. (1999): Approximate inverse banded matrix techniques, Engineering Computations (Inter. J. for Computer-Aided Engineering and Software) 16(3), 337-346. |

[73] | Gravvanis G. A. (1998): An approximate inverse matrix technique for arrowhead matrices, Inter. J. Comp. Math. 70, 35-45. |

[74] | Gravvanis G.A. (1996): The rate of convergence of explicit approximate inverse preconditioning, Inter. J. Comp. Math. 60, 77-89. |

[75] | Gravvanis G.A., Lipitakis E.A. (1996): An explicit sparse unsymmetric finite element solver, Communications in Numerical Methods in Engineering 12, 21-29. |

[76] | Gravvanis G.A., Lipitakis E.A. (1996): A three dimensional explicit preconditioned solver, I. J. Computer & Mathematics with Applications 32(2), 111-131. |

[77] | Gravvanis G.A. (1995): Explicit preconditioned methods for solving 3D boundary value problems by approximate inverse finite element matrix techniques, I. J. Comp. Math. 56, 77-93. |

[78] | Lipitakis E.A., Gravvanis G.A. (1995): Explicit preconditioned iterative methods for solving large unsymmetric finite element systems, Computing 54 (2), p167-183. |

[79] | Gravvanis G.A. (1994): A three dimensional symmetric linear equation solver, Communications in Numerical Methods in Engineering 10(9), 717-730. |

[80] | Lipitakis E.A., Gravvanis G.A. (1994): Explicit preconditioned methods for computing the inverse and pseudoinverse solutions of unsymmetric finite element systems of linear equations, accepted I. J. Mathematical Modelling and Scientific Computing 4, 886-893. |

[81] | Lipitakis E.A., Gravvanis G.A. (1992): A class of explicit preconditioned conjugate gradient methods for solving large finite element systems, Intern. J. Comp. Math. 44, 189-206. Also In "Preconditioned Iterative methods", Series: Topics in Computer Mathematics 4, ed. D. J. Evans, p255-272, Gordon and Breach Science Publishers, 1994. |

[82] | Lipitakis E.A., Gravvanis G.A. (1992): The convergence rate and complexity of preconditioned iterative methods based on approximate finite element matrix factorization, Bulletin of the Greek Mathematical Society, Special Issue on Computer Mathematics 33, 11-23. |

[83] | Lipitakis E.A., Gravvanis G.A. (1991): The numerical solution of large finite elements by explicit preconditioning semi-direct methods, Bulletin of the Greek Mathematical Society, Special Issue on Computer Mathematics 32, 63-82. Also In "Advances on Computer Mathematics and its Applications, E. A. Lipitakis ed., p237-256, World Scientific, 1993. |

### Publications: Conferences/Workshops/Symposiums

[1] | Editors: Hamid R. Arabnia, George A. Gravvanis: Proceedings of the 2010 International Conference on Scientific Computing, CSC 2010, July 12-15, 2010, Las Vegas, Nevada, USA CSREA Press 2010, USA, ISBN 1-60132-137-6 |

[2] | Editors: Hamid R. Arabnia, George A. Gravvanis, Ashu M. G. Solo: Proceedings of the 2010 International Conference on Foundations of Computer Science, FCS 2010, July 12-15, 2010, Las Vegas, Nevada, USA CSREA Press 2010, USA, ISBN 1-60132-142-2 |

[3] | Editors: Hamid R. Arabnia, George A. Gravvanis, Ashu M. G. Solo: Proceedings of the 2010 International Conference on Grid Computing & Applications, GCA 2010, July 12-15, 2010, Las Vegas, Nevada, USA CSREA Press 2010, USA, ISBN 1-60132-144-9 |

[4] | Editors: Hamid R. Arabnia, George A. Gravvanis: Proceedings of the 2009 International Conference on Grid Computing & Applications (GCA 2009), CSREA Press, July 13-16, 2009, Las Vegas Nevada, USA, ISBN 1-60132-105-8 |

[5] | Editors: Hamid R. Arabnia, George A. Gravvanis: Proceedings of the 2009 International Conference on Foundations of Computer Science (FCS 2009), CSREA Press, July 13-16, 2009, Las Vegas Nevada, USA, ISBN 1-60132-103-1 |

[6] | Editors: Hamid R. Arabnia, Rose Joshua, Iyad A. Ajwa, George A. Gravvanis: Proceedings of the 2004 International Conference on Algorithmic Mathematics and Computer Science (AMCS '04), CSREA Press, 21-24 June 2004, Monte Carlo Resort, Las Vegas, Nevada, USA, ISBN 1-932415-34-3 |

[7] | Editors: Hamid R. Arabnia and George A. Gravvanis: Proceedings of the 2005 International Conference on Scientific Computing (CSC '05), CSREA Press, 20-23 June 2005, Monte Carlo Resort, Las Vegas, Nevada, USA, ISBN 1-932415-62-9 |

[8] | Filelis-Papadopoulos C.K., Gravvanis G.A. and Lipitakis E.A. (2011): Higher order Finite Difference Preconditioned Scheme: A multithreaded approach, PCI 2011, to appear |

[9] | Matskanidis P.I., Gravvanis G.A., Giannoutakis K.M. (2011): A note on parallel finite element approximate inverses using OpenMP on multicore systems, PCI 2011, to appear |

[10] | Gravvanis G.A., Matskanidis P.I., Giannoutakis K.M. and Lipitakis E.A. (2010): Finite Element Approximate Inverse Preconditioning using POSIX threads on multicore systems, Proceedings of the International Multiconference on Computer Science and Information Technology 2010, Vol. 5, pp. 297-302, IEEE Computer Society Press, ISBN 978-83-60810-22-4; ISSN 1896-7094. |

[11] | Gravvanis G.A., Filelis-Papadopoulos C.K., Giannoutakis K.M. and Lipitakis E.A. (2010): Approximate Inverse Preconditioning using POSIX threads on multicore systems, Conference in Numerical Analysis (NumAn 2010)-Recent Approaches to Numerical Analysis: Theory, Methods and Applications, 15-18 September 2010, Chania, Greece, to appear |

[12] | Violentis J.B., Platis A.N., Gravvanis G.A. and Koutras V.P. (2009): Electrical Substation Efficient Maintenance Policies Based On Semi-Markov Modeling and Approximate Inverse Preconditioning, CD-ROM Proceedings of the Ninth Hellenic-European Conference on Computer Mathematics and its Applications (HERCMA 2009), 24-26 September 2009, Athens, ed. A. Lipitakis (ISBN:978-960-88975-5-7); http://www.aueb.gr/pympe/hercma/proceedings2009/H09-FULL-PAPERS-1/VIOLENTIS_PLATIS_GRAVVANIS_KOUTRAS.pdf |

[13] | Saravakos P., Gravvanis G.A., Koutras V.P. and Platis A.N. (2009): A Comprehensive Approach to Software Aging and Rejuvenation on a Single Node Software System, CD-ROM Proceedings of the Ninth Hellenic-European Conference on Computer Mathematics and its Applications (HERCMA 2009), 24-26 September 2009, Athens, ed. A. Lipitakis (ISBN:978-960-88975-5-7); http://www.aueb.gr/pympe/hercma/proceedings2009/H09-FULL-PAPERS-1/SARAVAKOS_GRAVVANIS_KOUTRAS_PLATIS-H09-1.pdf |

[14] | Gravvanis G.A. and Giannoutakis K.M. (2008): An improved parallel algorithm for computing approximate inverses by reducing synchronizations, Proceedings of the Seventh International Symposium on Parallel and Distributed Computing 2008 (ISPDC 2008), Marek Tudruj (eds), 237-243, IEEE Computer Society Press, ISBN: 978-0-7695-3472-5 |

[15] | Giannoutakis K.M. and Gravvanis G.A. (2008): Parallel iterative methods based on finite element approximate inverses on uniprocessor and multicomputer systems, CD-ROM Proceedings of the Sixth International Conference on Engineering Computational Technology 2008, M. Papadrakakis and B.H.V. Topping, Civil-Comp Press (CD-ROM ISBN 978-1-905088-25-6) |

[16] | Violentis J.B., Koutras V.P., Platis A.N. and Gravvanis G.A. (2007): Asymptotic Availability of an Electrical Substation via a Semi-Markov Process computed by Generalized Approximate Inverse Preconditioning, CD-ROM Proceedings of the Eighth Hellenic-European Conference on Computer Mathematics and its Applications (HERCMA 2007), 20-22 September 2007, Athens, ed. E.A. Lipitakis (ISBN:978-960-88975-3-3); http://www.aueb.gr/pympe/hercma/proceedings2007/H07-FULL-PAPERS-1/VIOLENTIS-KOUTRAS-PLATIS-GRAVVANIS-1.pdf |

[17] | Vafopoulos M.N., Gravvanis G.A. and Platis A.N. (2007): New directions in computing on demand, CD-ROM Proceedings of the Eighth Hellenic-European Conference on Computer Mathematics and its Applications (HERCMA 2007), 20-22 September 2007, Athens, ed. E.A. Lipitakis (ISBN:978-960-88975-3-3); http://www.aueb.gr/pympe/hercma/proceedings2007/H07-FULL-PAPERS-1/VAFOPOULOS-GRAVVANIS-PLATIS-1.pdf |

[18] | Koutras V.P., Platis A.N. and Gravvanis G.A. (2007): Software rejuvenation on a grid computing environment for higher availability based on approximate inverse preconditioning, CD-ROM Proceedings of the Eighth Hellenic-European Conference on Computer Mathematics and its Applications (HERCMA 2007), 20-22 September 2007, Athens, ed. E.A. Lipitakis (ISBN:978-960-88975-3-3); http://www.aueb.gr/pympe/hercma/proceedings2007/H07-FULL-PAPERS-1/KOUTRAS-PLATIS-GRAVVANIS-1.pdf |

[19] | Giannoutakis K.M. and Gravvanis G.A. (2007): On the design of parallel finite element approximate inverses, Proceedings of the 2007 International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA '2007), H.R. Arabnia ed, vol. I, 292-298, CSREA Press. |

[20] | Epitropou V.N., Giannoutakis K.M. and Gravvanis G.A. (2007): Java multithreading based parallel preconditioned generalized conjugate gradient type methods, Proceedings of the Sixth International Symposium on Parallel and Distributed Computing 2007 (ISPDC 2007), Dieter Kranzlmuller, Wolfgang Schreiner and Jens Volkert (eds), 311-318, IEEE Computer Society Press, IEEE |

[21] | Koutras V.P., Platis A.N., Gravvanis G.A. (2007): Software rejuvenation for higher levels of grid availability, ESREL 2007, Risk, Reliability and Societal Safety, Aven & Vinnem (eds), 1723-1730, Taylor & Francis Group, ISBN 978-0-415-44786-7 |

[22] | Gravvanis G.A., Giannoutakis K.M. (2006): On the performance of parallel normalized explicit preconditioned conjugate gradient-type methods, 7th International Workshop on Parallel and Distributed Scientific and Engineering Computing (PDSEC-06), in conjunction with The 20th International Parallel and Distributed Processing Symposium (IPDPS-06), April 25-29, 2006, Rhodes, Greece, IEEE IPDPS 2006 CD-ROM Proceedings, General Co-Chair: Paul Spirakis and H. J. Siegel (ISBN: 1-4244-0054-6, ISSN: 1530-2075) |

[23] | Vafopoulos M.N., Gravvanis G.A. and Platis A.N. (2005): Inter-and trans-disciplinary semantic technologies, CD-ROM Proceedings of the Seventh Hellenic-European Conference on Computer Mathematics and its Applications (HERCMA 2005), 22-24 September 2005, Athens, ed. E.A. Lipitakis, ISBN:960-87275-8-8, http://www.aueb.gr/pympe/hercma/proceedings2005/H05-FULL-PAPERS-1/VAFOPOULOS-GRAVVANIS-PLATIS-1.pdf |

[24] | Petropoulou S.G., Bekakos M.P., Gravvanis G.A. (2005): E-prescribing and Telepharmacy, CD-ROM Proceedings of the Seventh Hellenic-European Conference on Computer Mathematics and its Applications (HERCMA 2005), 22-24 September 2005, Athens, ed. E.A. Lipitakis, ISBN:960-87275-8-8, http://www.aueb.gr/pympe/hercma/proceedings2005/H05-FULL-PAPERS-1/PETROPOULOU-BEKAKOS-TELEPHARMACY.pdf |

[25] | Gravvanis G.A., Giannoutakis K.M., Lipitakis E.A. (2005): Solving fully parameterized singularly perturbed non-linear parabolic and elliptic pde's by explicit approximate inverse fe matrix algorithmic methods, CD-ROM Proceedings of the Seventh Hellenic-European Conference on Computer Mathematics and its Applications (HERCMA 2005), 22-24 September 2005, Athens, ed. E.A. Lipitakis, ISBN:960-87275-8-8, http://www.aueb.gr/pympe/hercma/proceedings2005/H05-FULL-PAPERS-1/GRAVVANIS-GIANOUTAKIS-LIPITAKIS-1.pdf |

[26] | Gravvanis G.A., Giannoutakis K.M., Lipitakis E.A. (2005): On the numerical solution of fully parameterized singularly perturbed non-linear initial and boundary value problems, CD-ROM Proceedings of the 17th IMACS World Congress on Scientific Computation, Applied Mathematics and Simulation (IMACS 2005), Paris, France, July 11-15, 2005, http://sab.sscc.ru/imacs2005/papers/T2-I-119-0947.pdf |

[27] | Gravvanis G.A., Giannoutakis K.M. (2004): Parallel approximate finite element inverse preconditioning on distributed systems, Proceedings of the Third International Symposium on Parallel and Distributed Computing 2004 (ISPDC 2004) and the Third International Workshop on Algorithms, Models and Tools for Parallel Computing on Heterogeneous Networks (HeteroPar 2004), 277-283, IEEE Computer Society Press, IEEE |

[28] | Gravvanis G.A., Giannoutakis K.M., Bekakos M.P. (2004): Parallel Finite Element Approximate Inverse Preconditioning on symmetric multiprocessor systems, Proceedings of the International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA '2004), H.R. Arabnia eds, vol. I, 168-175, CSREA Press, 21-24 June 2004, Las Vegas, Nevada, USA. |

[29] | Gravvanis G.A., Giannoutakis K.M. (2004): Normalized isomorphic preconditioned methods for solving sparse non-linear systems, Proceedings of the International Conference on Algorithmic Mathematics & Computer Science (AMCS '2004), H.R. Arabnia, I.A. Ajwa and G.A. Gravvanis eds, 362-369, CSREA Press, 21-24 June 2004, Las Vegas, Nevada, USA. |

[30] | Gravvanis G.A., Bekakos M.P., Efremides O.B. (2003): Parallel implicit preconditioned conjugate gradient methods for solving biharmonic equations, Proceedings of the Sixth Hellenic-European Conference on Computer Mathematics and its Applications, 25-27 September 2003, Athens, ed. E.A. Lipitakis, vol. 2, 683-694. |

[31] | Georgiadis M.S., Bekakos M.P., Gravvanis G.A., Mantas I. (2003): Computational Spread Prediction and Effectiveness Control Measures for Foot and Mouth Disease, Proceedings of the Sixth Hellenic-European Conference on Computer Mathematics and its Applications, 25-27 September 2003, Athens, ed. E.A. Lipitakis, vol. 1, 290-300. |

[32] | Gravvanis G.A., Platis A.N., Giannoutakis K.M., Violentis J.B., Lipitakis E.A. (2003) : Performability evaluation of multitasking and multiprocessor systems by explicit approximate inverses, Proceedings of the International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA '2003), H.R. Arabnia and Youngsong Mun eds, vol. III, 1324-1331, CSREA Press, 23-26 June 2003, Las Vegas, Nevada, USA. |

[33] | Giannoutakis K.M., Gravvanis G.A. (2002): A Normalized Explicit Preconditioned Conjugate Gradient method for solving sparse non-linear systems, Proceedings of the International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA '2002), H.R. Arabnia eds, vol. I, 107-113, CSREA Press, 24-27 June 2002, Las Vegas, Nevada, USA. |

[34] | Gravvanis G.A., Platis A.N., Violentis J.B., Giannoutakis K.M. (2002): Performability evaluation of a replicated database system by explicit approximate inverses, Proceedings of the International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA '2002), H.R. Arabnia eds, vol. I, 114-120, CSREA Press, 24-27 June 2002, Las Vegas, Nevada, USA. |

[35] | Gravvanis G.A. (2001) : Finite difference schemes and domain decomposition explicit approximate inverses, Proceedings of the Fifth Hellenic-European Conference on Computer Mathematics and its Applications, 20-22 September 2001, Athens, ed. E.A. Lipitakis, Vol 2, p605-612. |

[36] | Gravvanis G.A. (2000): Solving parabolic and nonlinear 1D problems with periodic boundary conditions, CD-ROM Proceedings of the European Congress on Computational Methods in Applied Sciences and Engineering 2000 (ECCOMAS 2000), Barcelona, 11-14 September 2000. |

[37] | Gravvanis G.A. (2000): Solving initial value problems by explicit domain decomposition approximate inverses, CD-ROM Proceedings of the European Congress on Computational Methods in Applied Sciences and Engineering 2000 (ECCOMAS 2000), Barcelona, 11-14 September 2000. |

[38] | Gravvanis G.A. (2001): Parallel preconditioned algorithms for solving special tridiagonal systems, invited half-hour lecture, Proceedings of Dynamic Systems and Applications, G.S. Lade, N.G. Medhin, M. Sambandham eds., Vol. III, 241-248, Dynamic Publishers. Third International Conference on Dynamical Systems and Applications, Atlanta, USA, 26-29 May 1999. |

[39] | Gravvanis G.A. (1998): Solving non-linear boundary value problems in three dimensions by explicit preconditioning, Proceedings of the International Conference on Advanced Computational Methods in Engineering, 2-4 September 1998, University of Ghent, Belgium, eds, R. Van Keer, B. Verhegghe, M. Hogge, E. Noldus, Part 2 : Contributed Papers, pp. 755-762, Shaker Publishing B.V., Maastricht, The Netherlands |

[40] | Gravvanis G.A. (1998): On the convergence rate of preconditioned iterative methods, Proceedings of the International Conference on Advanced Computational Methods in Engineering, 2-4 September 1998, University of Ghent, Belgium, eds, R. Van Keer, B. Verhegghe, M. Hogge, E. Noldus, Part 2 : Contributed Papers, pp. 763-770, Shaker Publishing B.V., Maastricht, The Netherlands |

[41] | Gravvanis G.A. (1996): Using explicit preconditioned schemes based on sparse approximate inverse finite element matrices for solving initial value problems in three dimensions, 9th Conference on the Mathematics of Finite Element and Applications, (MAFELAP 96), 25-28 June 1996, Brunel University, Brunel Institute of Computational Mathematics (BICOM), Summaries of Papers, p.49, 1996. |

[42] | Gravvanis G.A. (1996): Solving non-linear unsymmetric finite element systems, 9th Conference on the Mathematics of Finite Element and Applications (MAFELAP 96), 25-28 June 1996, Brunel University, Brunel Institute of Computational Mathematics (BICOM), Summaries of Papers, p. 50, 1996. |

[43] | Gravvanis G.A., Lipitakis E.A. (1994): Using generalized approximate inverse finite element methods for the numerical solution of initial/boundary value problems, Proceedings of the Second Hellenic-European Conference on Mathematics and Informatics, 22-24 September 1994, Athens, ed. E.A. Lipitakis, Vol 2, p829-838, Hellenic Mathematical Society. |

[44] | Gravvanis G.A., Lipitakis E.A. (1994): Using Explicit Preconditioning Schemes for solving initial/boundary value problems, 8th Conference on the Mathematics of Finite Element and Applications, Highlights 1993, ed. J. R. Whiteman, p373, Wiley. |

[45] | Lipitakis E.A., Gravvanis G.A. (1993): Hybrid Implicit-Explicit schemes by approximate inverse finite element matrix techniques for solving parabolic partial differential equations, Proceedings of the First Conference on Mathematics and Informatics, ed. E.A. Lipitakis, p345-356, Hellenic Mathematical Society. |

[46] | Lipitakis E.A., Gravvanis G.A. (1992): Explicit Preconditioned iterative methods for solving parabolic partial differential equations in three-space variables, Advances in Computer Methods for Partial Differential Equations-VII, Proceedings of the Seventh IMACS International Conference on Computer Methods for Partial Differential Equations, 22-24 June 1992, Vichnevetsky, R., Knight D., Richter G., eds., p 446-451, IMACS. |

[47] | Gravvanis G.A., Lipitakis E.A. (1992): The numerical solution of initial/boundary value problems by preconditioned iterative methods, in the Proceedings of the 2nd Panhellenic Conference on Mathematical Analysis, University of Athens, 14-15 February 1992, Greece |

[48] | Lipitakis E.A., Gravvanis G.A. (1991): Implicit preconditioned methods based on root-free sparse finite element factorization techniques, Proceedings of the 13th IMACS World Congress on Computation And Applied Mathematics, eds. Vichnevetsky, R., Miller, J.J.H., Volume 1, p449-450, 1991, Trinity College, July 1991, Dublin, Ireland. |

[49] | Lipitakis E.A., Gravvanis G.A. (1990): A fast direct method for solving elliptic boundary value problems on multiprocessor systems, Proceedings of the International Conference on Numerical Methods in Engineering : Theory and Applications, eds Pande, G.N., Middleton, J., p622-632, Elsevier Applied Science. |

### Publications: Books/Book Chapters

[1] | Editors: Gravvanis G.A., Morrison J.P., Arabnia H.R. and Power D. (2009): Recent advances in Grid Technologies and Applications, Nova Science Publishers, ISBN: 978-1-60692-768-7 |

[2] | Editors: Bekakos M.P., Gravvanis G.A. and Arabnia H.R. (2006): Grid Technologies: Emerging from Distributed Architectures to Virtual Organizations, WIT Press, ISBN: 978-1-84564-055-2 |

[3] | Gravvanis G.A., Filelis-Papadopoulos C.K. and Giannoutakis K.M. (2011): Parallel Approximate Inverse Preconditioning using the Finite Difference Method: The General Purpose Graphics Processing Units approach, Trends in Parallel, Distributed, Grid and Cloud Computing for Engineering, P. Ivanyi and B.H.V. Topping (eds), 291-319, Computational Science, Engineering and Technology Series: 27, Saxe-Coburg Publications. Invited half-hour special review lecture, The Second International Conference on Parallel, Distributed, Grid and Cloud Computing for Engineering (PARENG 2011), 12-15 April 2011, Ajaccio, Corsica, France. |

[4] | Gravvanis G.A., Giannoutakis K.M. and Iatridis N.D. (2010): Fast PageRank computation for Web Information Retrieval by Parallel Generalized Approximate Inverse Preconditioning, Developments and Applications in Engineering Computational Technology, Computational Science, Engineering and Technology Series: 26, B.H.V. Topping, J.M. Adam, F.J. Pallares, R. Bru and M.L. Romero (eds), pp. 307-335, Saxe-Coburg Publications. Invited half-hour special review lecture, Seventh International Conference on Engineering Computational Technology 2010 (ECT 2010) |

[5] | Gravvanis G.A. and Giannoutakis K.M. (2009): High Performance Preconditioned Iterative Methods. Parallel, Distributed and Grid Computing for Engineering, B.H.V. Topping and P. Ivanyi (eds), 275-308, Computational Science, Engineering and Technology Series: 21, Saxe-Coburg Publications. Invited half-hour special lecture, First International Conference on Parallel, Distributed and Grid Computing in Engineering (PARENG 2009), 6-8 April 2009, Pecs, Hungary |

[6] | Kehagias D.D., Tzovaras D., Gravvanis G.A. (2008): An Agent-based Approach for the Discovery, Composition and Orchestration of Grid Web Service, Nova Science Publishers, to appear |

[7] | M.P. Bekakos, G.A. Gravvanis, E.S. Bazoukis, and K.M. Giannoutakis (2006): Towards a pilot grid platform for internet high performance computations, In "Grid Technologies: Emerging from Distributed Architectures to Virtual Organizations", eds., M.P. Bekakos, G.A. Gravvanis and H.R. Arabnia, 209-239, WIT Press, ISBN: 978-1-84564-055-2 |

[8] | M. Vafopoulos, G.A. Gravvanis and A.N. Platis (2006): The personal grid e-workspace, In "Grid Technologies: Emerging from Distributed Architectures to Virtual Organizations", eds., M.P. Bekakos, G.A. Gravvanis and H.R. Arabnia, 363-389, WIT Press, ISBN: 978-1-84564-055-2 |