Publications

Invited Book Chapters

  1. Ashkan Ashrafi, “Walsh-Hadamard Transforms: A Review“, Advances in Imaging and Electron Physics, Vol. 201, London, UK: Elsevier Inc., pp. 1-55, 2017.

Journal Papers

  1. Stephanie Ries, Siddhi Tavildar, Rohan Rohilla, Connor Sperling and Ashkan Ashrafi, “Patterns of Cortical Interactivity Supporting Speech Production and Lexical Retrieval: A Graph Signal Processing Approach at the Individual Level,” J. of Neurolinguistics, Vol. 56, 100936, Nov. 2020.
  2. S. Tavildar, Brian Mogen, Stavros Zanos, Stephanie Seeman, Steve Perlmutter, Eberhard Fetz, and Ashkan Ashrafi, “Inferring Cortical Connectivity From ECoG Signals Using Graph Signal Processing,” IEEE Access, vol. 7, pp. 109349-109362, 2019.
  3. Michael Martinez, and Ashkan Ashrafi, “Real-valued Single-tone Frequency Estimation Using Half-length Autocorrelation“, Digital Signal Processing, Vol. 83, pp. 98-106, 2018.
  4. Ashkan Ashrafi, “Optimization of the Quantized Coefficients  for DDFS Utilizing Polynomial Interpolation Methods”, IEEE Trans. on Circuits and Systems Part-II, Express Briefs, Vol. 61, No. 2, pp. 105-108, Feb. 2014.
  5. Ashkan Ashrafi, “The Frequency Domain Walsh Functions and Sequences: An Introduction”, Appl. Comput. Harmon. Anal. Vol. 36, No.2, pp. 348-353, March 2014.
  6. Ashkan Ashrafi and fredric j. harris, “A Novel Square-Root Nyquist Filter Design with Prescribe ISI Energy”, Signal Processing, Vol.93, No. 9, pp. 2626-2635, Sept. 2013
  7. Ashkan Ashrafi Antonio G.M. Strollo, and Oscar Gustafsson, “Hardware Implementation of Digital Signal Processing Algorithms”, Editorial, Journal of Electrical and Computer Engineering, Vol. 2013, Article ID: 782575, June 2013.
  8. Praveen K. Chaurasiya, Ashkan Ashrafi and Santosh Nagaraj, “Novel Spectrally Efficient UWB Pulses Using Zinc and Walsh Basis Functions”, The ETRI Journal, Vol 35, No. 3,pp.406-413, June 2013.
  9. Ashkan Ashrafi, “Optimized Linear Phase Square-Root Nyquist FIR Filters for CDMA IS-95 and UMTS Standards”, Signal Processing, Vol. 93, No. 4, pp. 866-873, April 2013.
  10. Tanya T. Nguyen, Ashkan Ashrafi, Jennifer D. Thomas, Edward P. Riley and Roger W. Simmons, “Children with Heavy Prenatal Alcohol Exposure have Different Frequency Domain  Signal Characteristics when Producing Isometric Force”, Neurotoxicology and Teratology Vol. 35, pp. 14-20, Jan.-Feb. 2013.
  11. Ashkan Ashrafi, “On The SFDR Upperbound in DDFS Utilizing Polynomial Interpolation Methods”, IEEE Trans. on Circuits and Systems Part-II Express Briefs, Vol. 59, No. 5, pp.307-311, May 2012.
  12. Ashkan Ashrafi, Reza Adhami and Aleksandar Milenković, “Direct Digital Frequency Synthesizers Based on the Quasi-Linear Interpolation Method”, IEEE Trans. on Circuits and Systems Part-I, Regular Papers, Vol. 57, No. 4, pp. 863-872, April 2010.
  13. Yuri B. Shtessel, Parisa Kaveh and Ashkan Ashrafi, “Harmonic Oscillator Utilizing Double-Fold Integral, Traditional and Second Order sliding Mode Control,” Journal of The Franklin Institute, Vol. 346, No.9, pp. 872-888, Nov. 2009.
  14. Ashkan Ashrafi and Reza Adhami, “Theoretical Upperbound of the Spurious Free Dynamic Range in Direct Digital Frequency Synthesizers Realized by Polynomial Interpolation Methods”, IEEE Trans. on Circuits and Systems Part-I, Regular Papers, Vol. 54, No.10, pp.2252-2261, Oct. 2007.
  15. Peter Meenen, Ashkan Ashrafi, and Reza Adhami, “The Utilization of a Taylor Series-Based Transformation in Fingerprint Verification,” Pattern Recognition Letters, Vol. 27, No.14, pp.1606-1618, October 2006.
  16. Ashkan Ashrafi and Reza Adhami, “Comments on ‘A 13-Bits Resolution ROM-Less Direct Digital Frequency Synthesizer Based on a Trigonometric Quadruple Angle Formula’,” IEEE Transactions on Very Large Scale Integration (VLSI) Systems, Vol.13, No.9, pp. 1096-1098, Sept. 2005.
  17. Ashkan Ashrafi and Peter M. Gibson “Eigenvalues of Hadamard powers of large symmetric Pascal matrices”, Linear Algebra and its Applications, Vol. 405, pp. 60-66, August 2005.
  18. Ashkan Ashrafi and Peter M. Gibson “An involutory Pascal matrix”, Linear Algebra and its Applications, Vol 387, pp. 277-286, August 2004.
  19. Ashkan Ashrafi, Reza Adhami, Laurie Joiner and Parisa Kaveh, “Arbitrary Waveform DDFS Utilizing Chebyshev Polynomials Interpolation“, IEEE Transactions on Circuits and Systems Part-I, Regular Papers, Vol 51, No.8, pp. 1468-1476, August 2004.
  20. Ashkan Ashrafi and Hossein Golnabi, “A High Precision Method for Measuring Very Small Capacitance Changes“, Rev. of Sci. Instrum., Vol. 70 (8), pp. 3483-87, August 1999.
  21. H. Golnabi and A. Ashrafi, “Phase Shift Generation and Monitoring by a Simple Circuit“,Rev. of Sci. Instrum., Vol. 76 (5), pp. 2017-2019, 1996.
  22. H. Golnabi and A. Ashrafi, “Producing 180° out of Phase Signals from an Input Sinusoidal Waveform“, IEEE Transactions on Instrum. and Meas., Vol. 45, No.1, pp. 312-314, Feb. 1996.
  23. H. Golnabi and A. Ashrafi, “Theoretical Studies of Electrical Characteristics of the Nitrogen Laser“, Journal of Engineering, IR Iran, Vol.7, No.3, pp. 143-153, August 1994.

Conference Papers

  1. Siddhi Tavildar and Ashkan Ashrafi, “Application of Multivariate Empirical Mode Decomposition and Canonical Correlation Analysis for EEG motion Artifact Removal”, Conference on Advances in Signal Processing (CASP 2016), June 2016.
  2. Ujjal Bhowmik, A. Ashrafi, and Reza Adhami “A Fingerprint Verification Algorithm Using the Smallest Minimum Sum of Closest Euclidean Distance”, Proc. of the 19th International Conference on Electronics, Communications and Computers, CONIELECOMP 2009, pp.90-95, May 2009.
  3. A. Ashrafi, and Sudheep Thota, “A Novel Pre-Truncated Fixed-Width Digital Squarer”, Proc. of the IEEE 2008 Midwest Symposium on Circuits and Systems MWSCAS-2008, pp.959-961, August 2008.
  4. A. Ashrafi, A. Milenkovic and R. Adhami, “A 1GHz Direct Digital Frequency Synthesizer Based on the Quasi-Linear Interpolation Method”, Proc. of the IEEE International Symposium on Circuits and Systems ISCAS-2007, May 2007.
  5. A. Ashrafi and R. Adhami, “An Optimized Direct Digital Frequency Synthesizer Based on Even Fourth Order Polynomial Interpolation,” Proc. of the IEEE 38th Southeastern Symposium on System Theory, pp. 109-113, March 2006.
  6. A. Ashrafi and R. Adhami, “A Direct Digital Frequency Synthesizer Utilizing Quasi-Linear Interpolation Method,” Proc. of the IEEE 37th Southeastern Symposium on System Theory, pp.144-148, March 2005.
  7. P. Kaveh, A. Ashrafi and Y. Shtessel, “Robust Sliding Mode Harmonic Oscillator Suitable for Low Frequencies,” Proc. of the IEEE 37th Southeastern Symposium on System Theory, pp.249-252, March 2005.
  8. P. Kaveh, A. Ashrafi, Y. Shtessel, “Integral and Second Order Sliding Mode Control of Harmonic Oscillator”, Proc. of the 44th IEEE Conference on Decision and Control and European Control Conference (CDC-ECC’05), pp. 3941 – 3946, December 2005.
  9. P. Kaveh, A. Ashrafi and Y. Shtessel, “Robust Harmonic Oscillator Control via Integral and High Order Sliding Modes”, Proc. of the 8th International Workshop on Variable Structure Systems (VSS’04).
  10. Ashkan Ashrafi, Zexin Pan, Reza Adhami and B. Earl Wells, “A Novel ROM-less DDFS Based on Chebyshev Polynomial Interpolation”, Proc. of IEEE 36thSoutheastern Symposium on System Theory, pp. 393-397, March 2004.
  11. Ashkan Ashrafi, Reza Adhami and Paul Cox, “A Simple Wide-Band Frequency Independent Quadrature Phase Shifter”, Proc. of IEEE 34th Southeastern Symposium on System Theory, March 2002.
  12. Hossein Golnabi, A. Ashrafi and Habib. Golnabi, “Fiber Optic Sensing of Displacement and Pressure”, Proceedings of the 6th International Conference on Flexible Automation and Intelligent Manufacturing (FAIM’96), Begell House, New York, pp. 149-158, 1996.
  13. H. Golnabi and A. Ashrafi, “Design and Construction of a Reliable Fiber Optic Sensor”, Proc. of the 5th International Conference on Flexible Automation and Intelligent Manufacturing (FAIM’95), Begell House, New York, pp. 910-917, 1995.
  14. H. Golnabi and A. Ashrafi, “Theoretical and Experimental Investigation of a Computer-Controlled Angle Tuning System”, Proc. of the 4th International Conference on Flexible Automation and Integrated Manufacturing (FAIM’94), Begell House, New York, pp.834-843, 1994.
  15. H. Golnabi and A. Ashrafi, “The Role of Sensor Systems in Automated Manufacturing”, Proc. of the 4th International Conference on Flexible Automation and Integrated Manufacturing(FAIM’94), Begell House, New York, pp. 646-654, 1994.

Poster Presentations

  1. Roger W. Simmons, Ashkan Ashrafi, Tanya T. Nguyen, Susan S. Levy, Jennifer D. Thomas, Edward P. Riley.  “Frequency response characteristics of isometric force regulation in children with prenatal alcohol exposure”, Society for Neuroscience, San Diego Nov. 2010.

Patents

  1. Ashkan Ashrafi, “Rectangular Power Densities of Orthogonal Functions”, United States Patent 9,036,459, May 19th, 2015.

Tutorials

  1. Amith Dharwadkar and Ashkan Ashrafi, “Cadence Tutorial” (PDF)
  2. Mark Sison Manalo and Ashkan Ashrafi, “Tutorial: Xilinx Virtex-5 FPGA ML506 Edition”.(PDF)
  3. Mark Sison Manalo and Ashkan Ashrafi, “Implementing Filters on FPGA” (PDF)
  4. Mark Sison Manalo and Ashkan Ashrafi, “USB Interfacing and Real-Time Data Plotting with MATLAB” (PDF)
  5. Colin Fera, Matthew Luscher and Ashkan Ashrafi, “Virtex-6 ML605 Development Board With  4-DSP FMC-150 ADC/DAC”. (PDF) (Files)
  6. Danny Toma and Ashkan Ashrafi, “Fourier Interpolation on an FPGA”. (PDF)
  7. David Walker-Howell and Ashkan Ashrafi, “Parametric IIR Filtering on an FPGA”. (PDF) (File1) (File2)