Dr. Amir-Homayoon Najmi

Applied Physics

Current Courses

Personal Bio

Dr. Najmi has a B.A. degree in Mathematics from Cambridge University, and a D.Phil. in Theoretical Physics from Oxford University.  He was a Fulbright scholar at the Relativity Centre, University of Texas, a Research Associate and Instructor at the University of Utah and a Research Physicist at Shell Oil Bellaire Geophysical Research centre prior to joining the Johns Hopkins University APL.  He has published research in wide areas including quantum field theory in cosmological space-times, seismic inverse scattering, adaptive signal processing applied to electromagnetic waves and biosurveillance.  He has developed and taught courses in Relativity, Astrophysics, Cosmology, Advanced Signal Processing and Wavelet Signal Analysis at the Whiting school.  His book Wavelets: A Concise Guide was published by the Johns Hopkins University Press in 2012.

Education History

  • B.A. - Mathematics Mathematics, Cambridge University
  • Master of Mathematics Mathematics, Cambridge University
  • M.A. - Mathematics Mathematics, Cambridge University
  • D.Phil. Theoretical Physics, Oxford University

Work Experience

Senior Professional Staff, JHU Applied Physics Laboratory

Publications

Book:
Wavelets: A Concise Guide, 2012, Johns Hopkins University Press.


Papers:

1. "Extended Solutions of Interacting Field Theories and Topological Charge": 1977, University of Texas Preprint, NATO Cargese Summer School on Gravity Research.
2. "Non-Particle States of Quantum Free Field Theories": 1980, Third Symposium on Quantum Gravity, Oxford.
3. "Quantum Field Theory in Curved Space-Times": 1982, Thesis for the D.Phil. degree at the University of Oxford.
4. "Construction of States for Quantum Fields in Non-Static Space-Times": 1983, Physical Review D., Vol. 28, No. 8, pp. 1907-1915.
5. "Spin-1/2 Quantum Field Theory in Non-Static Space-Times: I. Construction of States": 1984, Journal of Mathematical Physics, Vol. 25, No. 3, pp. 623-628.
6. "Quantum States and the Hadamard Form: I. Energy Minimization for Scalar Fields": 1984, Physical Review D., Vol. 30, No. 8, pp. 1733-1741.
7. "Quantum States and the Hadamard Form: II. Energy Minimization for Spin-1/2 Fields": 1984, Physical Review D., Vol. 30, No. 12, pp. 2573-2578.
8. "A Constraint on Physical Quantum States in Cosmological Space-Times": 1985, Gravity Research Foundation annual competition essay; Journal of General Relativity and Gravitation, Vol. 17, No. 6, pp. 573-578.
9. "Quantum States and the Hadamard Form: III. Constraints on the Complex Structure": 1985, Physical Review D., Vol. 32, No. 8, pp. 1942-1948.
10. "Applications of Digital Signal processing in Exploration Geophysics": 1986, invited lecture at the 26th Annual Engineering Seminar Series on Digital Image Processing in Industry, Science and Technology; St. Mary's University, San Antonio, Texas.
11. "Multiple Reflection Suppression in Deep submarine Canyons": 1986, SEG Geophysics Conference, The Hague, Netherlands.
12. "A Formula for Geometric Spreading in Isotropic and Inhomogeneous Fluid Media": 1986, SEG Geophysical Conference, The Hague, Netherlands.
13. "Plane wave Reflectivity and Acoustic Impedance Sections from Migrated Sections": 1987, SEG Geophysical Conference, Houston.
14. "Useful Formulae for 2.5 Dimensional Forward Modeling in a Linear Background Velocity": 1987, SEG Geophysics Conference, Houston.
15. "True Amplitude Migration in a Linear Velocity Background": 1987, SEG Geophysics Conference, Houston.
16. "Born theory of Inversion and True Amplitude Kirchhoff Migration": 1988, SEG Geophysics Conference, Boston.
17. "Birefringence Effects on Converted Data in the Gulf of Mexico": 1988, SEG Geophysics Conference, Boston.
18. "Analysis of Travel-Time Inversion Techniques for Cross-Hole Imaging": 1988, SEG Geophysics Conference, Boston.
19. "A New Algorithm for Transforming Converted Shear Data to Normal Incidence": 1989, SEG Geophysical Conference, New Orleans.
20. "A Simple Method of Alias Noise Reduction in Migration of Seismic Data": 1989, SEG Geophysics Conference, New Orleans.
21. "The Wigner Distribution: A Time-Frequency Analysis Tool": 1994, cover page article in the Johns Hopkins University APL Technical Digest, Vol. 15, No. 4.
22. "Exact Solutions for the Geometrical Spreading Function in Inhomogeneous Fluid Media": 1996, GEOPHYSICS, Vol. 61, No. 3, pp. 1189-1197.
23. "Wavelet Filtering of Sferics in ELF Electromagnetic Data": 1996, paper accepted at the International Conference on Signal Processing Applications and Technology, Boston.
24. "The Continuous Wavelet Transform and Variable Resolution Time-Frequency Analysis": 1997, Johns Hopkins University APL Technical Digest, Vol.18, No. 1.
25. "Time-Frequency Decomposition of Signals": 1997, Americal Geological Union Spring Meeting in Baltimore.
26. "Time-Frequency Decomposition of Signals in a Current Disruption Event": 1997, Geophysical Research Letters, Vol. 24, No. 24, pp. 3157-3160.
27. "Wavelet Transforms and Time-Frequency Decomposition": 1997, Invited lecture at the International Conference on Mathematics and its Applications, Imperial College, University of London.
28. "Time-Frequency Analysis of Pediatric Murmurs", 1998, Int. Biomed.Optics Symposium, San Jose, CA.
29. "Live Organism Toxicity Monitoring: Signal Analysis": 1999, Johns Hopkins University APL Technical Digest, Vol.20, No. 3.
30. "Acoustic Detection of Aerosol Dissemination", Intellectual Property Disclosure, 18 May, 2000.
31. “High Metal Mine Classification Algorithm: A Bayesian approach", Janney Fellowship awarded, 2002.
32. “Estimation of hospital emergency room data using OTC pharmaceutical sales and Least Mean Square filters”, BMC Medical Informatics and Decision Making 2004, 4:5 (15 March 2004)
33. “Estimation of Hospital Emergency Room Data Using OTC Pharmaceutical Sales using Normalized LMS filters”, Proceedings of the 7th International Conference on Signal Processing-ICSP'04- Beijing, 31 Aug-4 Sep 2004.
34. "An adaptive prediction and detection algorithm for multistream syndromic surveillance", BMC Medical Informatics and Decision Making 2005, 5:33. (12 Oct 2005)
35. "Predicting Syndromic Data Using Adaptive Recursive Least Squares for Surveillance” , Public Health Information Network conference sponsored by CDC, Atlanta, August 2007.
36. "Recursive Least Squares & Weekday corrections for BioSurveillance”, International Society for Disease Surveillance Sixth conference, Indianapolis, Oct 2007.
37. "Data Normalization in Biosurveillance: An Information-Theoretic Approach”, American Medical Informatics Association 2007 Annual Symposium in Indianapolis, October 2007, Chicago, IL, November 10-14 2007. Paper published in Advances in Disease Surveillance 4, 108 (2007).
38. "Developments in the roles, features and evaluation of alerting algorithms for disease outbreak monitoring", JHUAPL Technical Digest, Vol.27, Number 4, 313-331.
39. "Recursive least squares background prediction of univariate syndromic surveillance data", BMC Medical Informatics and Decision Making 2009, 9:4., (2009)
40. "Reducing False Alarms in Syndromic surveillance", Statistics in Medicine, (2011) [DOI: 10.1002/sim.4204]
41. "Characterization of Subdural Stimulation-Induced Afterdischarge Activity Using the Continuous Wavelet Transform", IEEE Trans. BioMedical Engineering, Vol.63, No.7 (2016).

Honors and Awards

  • Merle Tuve Fellow, Johns Hopkins Medical Institute Neurology Faculty (2013)
  • Fulbright Scholar (1977)