Research Interests

Digital signal and image processing research in the areas of computer algorithms, numerical methods, sensor technologies, visualization techniques, and multidimensional signal processing.  Particular interest has been in tomographic image and volume reconstruction using specialized model-based inversion methods.

Research and Professional Experience

36 year R&D career at Lawrence Livermore National Laboratory; Retired 2015; Now consultant to LLNL

Memberships

• IEEE, SPIE

Patents

• 2007 US Patent No. 7,285,092:  Computerized Ultrasound Risk Evaluation
• 2006 US Patent No. 6,984,210:  Diagnostic Analysis of Ultrasound Data
• 2004 US Patent No. 20040167396 A1:  Quantitative full-aperture ultrasound tomography
• 2004 US Patent No. 20040122325 A1:  Diagnostic Analysis of Ultrasound Data
• 2004 US Patent No. 20040122304 A1:  Computerized Ultrasound Risk Evaluation Quantitation of Absorbed or Deposited Materials on a Substrate that Measures Energy deposition.
• 1995 US Patent No. 5,475,726:  Limited-data Cone-beam Computed Tomography

Ph.D. Electrical Engineering and Computing Science, UC Davis, 1991

M.S. Electrical and Biomedical Engineering, Carnegie-Mellon U., 1978

B.S. Electrical Engineering and Computer Science, UC Berkeley, 1977

Azevedo, S.G., Martz, H.E., Aufderheide, M.B., Brown, W.D., Champley, K.M., Kallman, J.S., Roberson, G.P., Schneberk, D., Seetho, I.M., and Smith, J.A., 2016. System-independent characterization of materials using dual-energy computed tomography. IEEE Transactions on Nuclear Science, 63(1), pp.341-350.

Martz, H.E., Seetho, I.M., Champley, K.E., Smith, J.A. and Azevedo, S.G., 2016, May. CT dual-energy decomposition into x-ray signatures ρe and Ze. In SPIE Defense+ Security (pp. 98470D-98470D). International Society for Optics and Photonics.

Kallman, J.S., Azevedo, S. and Martz, H.E., 2014, March. Effects of powder morphology and particle size on CT number estimates. In IS&T/SPIE Electronic Imaging (pp. 90200K-90200K). International Society for Optics and Photonics.

Kallman, J.S. and Azevedo, S.G., 2012. Ray-weighted constrained-conjugate-gradient tomographic reconstruction for security applications. Proc. 2nd Intl. Mtg. on image formation in X-ray CT, pp.305-9.

Littrup, P.J., Duric, N., Azevedo, S., Chambers, D., Candy, J.V., Johnson, S., Auner, G., Rather, J. and Holsapple, E.T., 2002. Computerized ultrasound risk evaluation (CURE) system: Development of combined transmission and reflection ultrasound with new reconstruction algorithms for breast imaging. In Acoustical Imaging (pp. 175-182). Springer US.

Azevedo, S.G., Mast, J.E., Nelson, S.D., Rosenbury, E.T., Jones, H.E., McEwan, T.E., Mullenhoff, D.J., Hugenberger, R.E., Stever, R.D., Warhus, J.P. and Wieting, M.G., 1996, November. HERMES: A high-speed radar imaging system for inspection of bridge decks. In Nondestructive Evaluation Techniques for Aging Infrastructure and Manufacturing (pp. 195-204). International Society for Optics and Photonics.

Roberson, G.P., Martz, H.E., Decman, D.J., Camp, D.C., Azevedo, S.G. and Keto, E.R., 1994, February. Characterization of waste drums using nonintrusive active and passive computed tomography. In Proceedings of the Nondestructive Assay & Nondestructive Examination Waste Characterization Conference (pp. 14-16).

Azevedo, S.G., Martz, H.E. and Schneberk, D.J., 1993, December. Potential of computed tomography for inspection of aircraft components. In SPIE's 1993 International Symposium on Optics, Imaging, and Instrumentation (pp. 47-57). International Society for Optics and Photonics.

Martz, H.E., Roberson, G.P., Schneberk, D.J. and Azevedo, S.G., 1991. Nuclear-spectroscopy based, first-generation, computerized tomography scanners. IEEE transactions on nuclear science, 38(2), pp.623-635.

Martz, H.E., Roberson, G.P., Skeate, M.F., Schneberk, D.J. and Azevedo, S.G., 1991. Computerized tomography studies of concrete samples. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 58(2), pp.216-226.

Martz, H.E., Schneberk, D.J., Roberson, G.P., Azevedo, S.G. and Lynch, S.K., 1991. Computerized tomography of high explosives. In Nondestructive Characterization of Materials IV (pp. 187-195). Springer US.

Martz, H.E., Azevedo, S.G., Brase, J.M., Waltjen, K.E. and Schneberk, D.J., 1990. Computed tomography systems and their industrial applications. International Journal of Radiation Applications and Instrumentation. Part A. Applied Radiation and Isotopes, 41(10-11), pp.943-961.

Azevedo, S.G., Schneberk, D.J., Fitch, J.P. and Martz, H.E., 1990. Calculation of the rotational centers in computed tomography sinograms. IEEE transactions on nuclear science, 37(4), pp.1525-1540.

• Director of the Center for Advanced Signal and Image Sciences (CASIS) for eight years
• 2009 R&D100 Award winner:  Landmine Detection System (Project Leader)
• 2008 R&D100 Award winner:  SecureBox: National Security Through Secure Cargo
• 2000 R&D100 Award winner:  Waste Inspection Tomography for Nondestructive Assay
• 1998 R&D100 Award winner:  HERMES Bridge Inspection Project (Project Leader)
• 1998 National Academy of Engineering Young Investigator