I am currently the Research Manager of the Biomedical and Clinical Informatics Lab at the University of Michigan, under the direction of Kayvan Najarian. Previously, I was a Ph.D. student at The Graduate Center, CUNY; as well as the Infrastructure Manager of the Westport Public Schools.

My research interests are in theoretical computer science, with a focus on machine learning, cryptography, and computational group theory, and well as computational medicine and computer networking/network security.



  1. J. Gryak, D. Kahrobaei, C. Martinez-Perez, On The Conjugacy Problem in Certain Metabelian Groups, Glasgow Mathematical Journal, Cambridge University Press (preprint)
  2. J. Gryak, R. Haralick, D. Kahrobaei, Solving the Conjugacy Decision Problem via Machine Learning, Experimental Mathematics, Taylor and Francis (preprint)
  3. J. Gryak, D. Kahrobaei, The Status of Polycyclic Group-Based Cryptography: A Survey and Open Problems, Groups Complexity Cryptology, De Gruyter, Volume 8, Issue 2, 171--186 (2016) (preprint)

Preprints and Submitted Articles

  1. Z. Li, H. Derksen, J.Gryak, H. Ghanbari, P. Gunaratne, K. Najarian, Atrial Fibrillation Prediction using Recordings from Portable Devices, Submitted
  2. S. Ansari, J. Gryak, K. Najarian, Noise Detection in Electrocardiography Signal for Robust Heart Rate Variability Analysis: A Deep Learning Approach, Submitted
  3. A. Nguyen, S. Ansari, M. Hooshmand, K. Lin, H. Ghanbari, J. Gryak, K. Najarian, Comparative Study on Heart Rate Variability Analysis for Atrial Fibrillation Detection in Short Single-Lead ECG Recordings, Submitted
  4. H. Yao, W. Zhang, R. Malhan, J. Gryak, K. Najarian, Filter-Pruned 3D Convolutional Neural Network for Drowsiness Detection, Submitted
  5. H. Yao, C. Williamson, S.M.R. Soroushmehr, J. Gryak, K. Najarian, Hematoma Segmentation Using Dilated Convolutional Neural Network, Submitted
  6. M. Hooshmand, S.M.R. Soroushmehr, C. Williamson, J. Gryak, K. Najarian, Automatic Midline Shift Detection in Traumatic Brain Injury, Submitted
  7. N. Farzaneh, S.M.R. Soroushmehr, H. Patel, A. Wood, J. Gryak, D. Fessell, K. Najarian, Automated Kidney Segmentation for Traumatic Injured Patients through Ensemble Learning and Active, Submitted
  8. A. Wood, S.M.R. Soroushmehr, N. Farzaneh, K. Ward, D. Fessell, J. Gryak, K. Najarian, Fully Automated Spleen Localization and Segmentation Using Machine Learning and 3D Active Contours, Submitted
  9. R. Shen, Z. Li, L. Zhang, Y. Hua, M. Mao, Z. Li, Z. Cai, Y. Qiu, J. Gryak, K. Najarian, Osteosarcoma Patients Classification Using Plain X-Rays and Metabolomic Data, Submitted
  10. A. Gribov, K. Horan, J. Gryak, D. Kahrobaei, V. Shpilrain, S.M.R. Soroushmehr, K. Najarian, Medical Diagnostics Based on Encrypted Medical Data, Submitted


  1. J. Gryak, Solving Algorithmic Problems in Finitely Presented Groups via Machine Learning, City University of New York, April 2017