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Nonlinear Highlights


Michele Griffa

Post-Doc, Computational Physics

M. Griffa Image


Michele recently left LANL
for a position EMPA, Zurich.

  • EMPA
  • Swiss Federal Laboratories for Materials Testing & Research
  • Überlandstrasse 129
  • 8600, Dübendorf, Switzerland
  • +41 (0) 44 823 4789 - Phone
  • +41 (0) 44 823 4009 - FAX
  • michele.griffa@empa.ch
  • Personal Web Site


Research Interests

  • Time Reversal Acoustics in Solid Media
  • Nonlinear Elasticity
  • Ultrasonic and Seismic Imaging
  • High Performance Parallel Computing/Cluster Computing
  • Monte Carlo Methods for Inverse Problems
  • Soft Computing
  • Computational Systems Biology



  • Ph.D., Physics, Polytechnic of Torino, Dept. of Physics, January, 2007
  • M.S., Physics, University of Torino, Cum Laude, Thesis - 'The role of mechanical pressure, cellular adhesion and apoptosis in the growth of multicellular tumor spheroids: physical-mathematical modeling', 2003





  • Present - Los Alamos National Lab, EES-11
  • 2004 - 2006: Ph.D. student in Physics, XIX Cicle, Polytechnic of Torino, Dept. of Physics
  • 2003 - 2004: Research Fellow at the Department of Physics Polytechnic of Torino, Torino-Polytechnic Research Unit of the INFM-CNISM
  • Curriculum Vitae


Scientific & Technical Skills

  • Theoretical and Computational Physics: Continuum Mechanics, specifically Elasticity Theory and numerical simulation of elastic (acoustic and ultrasonic) wave propagation through heterogeneous materials; quantum theory of condensed matter; Monte Carlo methods in Materials Sciences
  • Scientific Computing: finite differences methods; finite elements methods; parallel computing with PC cluster (Beowulf clusters); scalar and parallel codes optimization for scientific computing; Soft Computing methods (Artificial Neural Networks, Genetic Algorithms, Bayesian methods); signal numerical processing for imaging purposes
  • Biomathematics: mathematical models of spatial-temporal tumor growth; biomechanical models of biological growth; Population Dynamics; reaction-diffusion equations and pattern formation in Developmental Biology; Dynamical Systems Theory for biological systems
  • Imaging and Inverse Problems Theory: imaging with ultrasounds for non-destructive evaluation of materials, probabilistic methods for the resolution of Inverse Problems, Genetic Algorithms for the solution of global optimization problems involved in Inversion
  • Cybernetics and Mathematical Systems Theory: characterization and analysis of dynamic systems; Stochastic Processes Theory for signal processing
  • Basic knowledge of Microelectronics and Physics of electronic devices (6 months of experience in a Microelectronics Lab)
  • Web technologies and Networking: basic knowledge of TCP/IP protocols and client-server architectures, development of static e dynamic HTML web pages, XML-based markup languages (DHTML, XHTML) for the Semantic Web, database technologies (server MySQL, SQL language, development of graphical user interfaces to SQL databases)
  • e-Science - Large scale scientific databases, web platforms for social networking in Science and Engineering; bibliographic databases; data and images post-processing through Grid Computing; since 2002, experience as a systems administrator: GNU/Linux PCs, Beowulf-like clusters of PCs for parallel computing; experience in scientific projects administrative-financial-bureaucratic management


Voluntary Services

  • Italian Red Cross, Aide and Tech, February 2003 to October 2006


Computer/Computing Skills

  • High-level programming Languages - C, C++, Pascal
  • Machine-Level Languages - Motorola 6800 Assembly language
  • Markup Languages - TeX/LaTeX, HTML, XML
  • Relational Databases - SQL, MySQL, R-DBMS
  • OS Expertise - GNU/Linux O.S.s, Fedora, SuSE, Mandrake (dal 2005, Mandriva) distros, MS Windows (NT, 2K, XP)
  • High Performance Computing/Parallel Computing
  • Parallel programming for GNU/Linux-based clusters with MPI (MPI-CH) (distributed-memory systems) (distributed-memory parallel systems)
  • Multi-threading programming for multi-core architecture and shared memory parallel computers (OpenMP)
  • Optimization of scalar code on GNU/Linux systems with an Intel Pentium architecture (i486, i586), Intel optimized compiler
  • System-administration of GNU/Linux-based clusters (Beowulf clusters) (OpenPBS)
  • IDE (Integrated Development Environments)
  • Develop, Eclipse, MS Visual Studio
  • Scientific Computing Environments - Matlab, Scilab



Published Papers in International Peer-Reviewed Journals
  • Anderson, B. E., Griffa, M., Larmat, L., Ulrich, TJ, and Johnson, P. A., "Time Reversal," Acoust. Today, 4 (1), p. 5-16 (2008).   (PDF File - 1.2 MB)
  • M. Griffa, B. E. Anderson, R. A. Guyer, T. J. Ulrich, P. A. Johnson, Investigation of the robustness of time reversal acoustics in solid media through the reconstruction of temporally symmetric sources, J. Phys. D: Appl. Phys. 41, 085415 (2008). (Abstract)
  • P.P. delsanto, C.A. Condat, N. Pugno, A.S. Gliozzi, M. Griffa, A Multilevel Approach to Cancer Growth Modeling, J. Theor. Biol. 250 (1), 16-24 (2007).
  • A.S. Gliozzi, M. Griffa, M. Scalerandi, Efficiency of Time Reversed Acoustics in Nonlinear Defect Imaging in Solids, J. Acous. Soc. America 120 (5), 2506-2517 (2006).
  • M. Scalerandi, M. Nobili, M. Griffa, A. Gliozzi, F. Bosia, A Preisach-Mayergoyz approach to fatigue induced irreversibility, Phys. Rev. B 73, 092103 (2006).
  • M. Bentahar, H. El. Aqra, R. El Guerjouma, M. Griffa, M. Scalerandi, Hysteretic elasticity in damaged concrete: quantitative analysis of slow and fast dynamics, Phys. Rev. B 73, 014116 (2006).
  • P.P. Delsanto, M. Griffa, C.A. Condat, S. Delsanto, L. Morra, Bridging the gap between mesoscopic and macroscopic models: the case of multicellular tumor spheroids, Phys. Rev. Lett. 94, 148105 (2005).
  • M. Griffa, M. Scalerandi, C. Camagna, Influence of the Medium Rigidity on the Growth of Multicellular Tumor Spheroids, European Physical Journal: Applied Physics 30, 65-71, 2005.
  • M. Griffa, M. Scalerandi, Environmental physical modulation of intrinsic tendency to growth of Multicellular Tumor Spheroids: in silico experiments, Phys. Scripta T118, 183 - 186 (2005).
  • M. Griffa, M. Scalerandi, Physical modeling and simulations of tumor growth and angiogenesis: predictions and new hypotheses, Physica Scripta, T118, 179 -182 (2005).
  • P.P. Delsanto, L. Morra, S. Delsanto, M. Griffa, C. Guiot, Towards a Model of Local and Collective Mechanisms in Multicellular Tumor Spheroids Growth, Phys. Scripta T118, 157, 160 (2005).
  • M. Scalerandi, M. Griffa, Modelling the coupling between apoptosis and host rigidity in the growth of Multicellular Tumour Spheroids, WSEAS Transactions on Biology and Biomedicines 1, 237 (2004).
  • M. Griffa, S. Delsanto, L. Morra, P.P. Delsanto, Mesoscopic Modeling of Multicellular Tumor Spheroids: Validation through a Quantitative Comparison with Experimental Data, WSEAS Transactions on Biology and Biomedicines 1, 249 (2004).
Papers in Proceedings of International Conferences
  • B.E. Anderson, TJ Ulrich, M. Griffa, P.A. Johnson, M. Scalerandi, A. Gliozzi, Selective Source Reduction to Identify Masked Smaller Sources Using Time Reversal Acoustics, Proceedings of QNDE (Quantitative Non-Destructive Evaluation) 2007 Conference, July 22nd - 27th 2007, Golden, Colorado, USA.
  • TJ Ulrich, B.E. Anderson, M. Griffa, Improving Focal Determination of Time Reversed Acoustic Signals, Proceedings of QNDE (Quantitative Non-Destructive Evaluation) 2007 Conference, July 22nd - 27th 2007, Golden, Colorado, USA.
  • B.E. Anderson, P.A. Johnson, TJ Ulrich, M. Griffa, Complex source imaging using time-reversal (TR): experimental studies of spatial and temporal resolution limits, Proceedings of the 153rd Meeting of the Acoustical Society of America, June 4th - 8th 2007, Salt Lake City, Utah, USA.
  • M. Griffa, P.A. Johnson, R.A. Guyer, T.J. Ulrich, B.E. Anderson, Time Reversal Acoustics (TRA) reconstruction of symmetric-in-time sources in solid elastic specimens: investigation of the effects of finite-size transducers on TRA in solids, Proc. XII International Workshop on Nonlinear Elasticity in Materials (IWNEM), Ajaccio (Corsica), June 3rd - 9th 2007.
  • M. Nobili, F. Bosia, A. Gliozzi, M. Griffa, M. Scalerandi, Acoustic Emission and Nonlinear Elasticity in Fatigue Induced Damage, Proceedings of the 12th International Congress on Sound and Vibration, ICSV12, Lisbon, July 11th - 14th 2005.
  • F. Bosia, P.P. Delsanto, A. Gliozzi, M. Griffa, M. Nobili, M. Scalerandi, Acoustic Emission and Nonlinear Hysteretic Elasticity: a combined model, Proceedings of the 12th International Congress on Sound and Vibration - ICSV12 - Lisbon, July 11th - 14th 2005.
  • M. Bentahar, R. El Guerjouma, M. Griffa, M. Scalerandi, Mèthodes émergents en acoustique non-linéaire pour le controle non destructif et le controle de santé des matériaux, Proceedings of the 17th French Congress of Mechanics, August 29th - September 2nd, Troyes (France).
  • S. Delsanto, L. Morra, M. Griffa, C. Demartini, A Genetic Algorithms' Approach to the Exploration of Paramter Space in Mesoscopic Multicellular Tumor Spheroids Models, Conference Proceedings, IEEE EMBC 2004 (26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society), 1-5 Sept. 2004, Vol. 1, 675-678.
Inclusions in Books
  • M. Scalerandi, M. Nobili, M. Griffa, A.S. Gliozzi and F. Bosia, Numerical Analysis of the Anomalous Elastic Behavior of Hysteretic Media: Quasi-Static, Dynamic and Relaxation Experiments, Chapter 17, pag. 267-284, in The universality of nonclassical nonlinearity/ with applications to NDE and Ultrasonics, edited by P.P. Delsanto, Springer (New York), 2006.
  • S. Delsanto, M. Griffa, L. Morra, Inverse Problems and Genetic Algorithms. Applications in NDE/NDT & Ultrasonics, Chapter 22, 369-386, in The universality of nonclassical nonlinearity/ with applications to NDE and Ultrasonics, edited by P.P. Delsanto, Springer (New York), 2006.


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