International Journal Papers
Mengqi Xing, Hyekyoung Lee, Zachery Morrissey, Moo K. Chung, K. Luan Phan, Heide Klumpp, Alex Leow, Olusola Ajilore, ''Altered dynamic electroencephalography connectome phase-space features of emotion regulation in social anxiety," NeuroImage, vol. 186, pp. 338-349, 2019.
Hyekyoung Lee, Eunkyung Kim, Seunggyun Ha, Hyejin Kang, Youngmin Huh, Youngjo Lee, Seonhee Lim, Dong Soo Lee, ''Volume entropy for modeling information flow in a brain graph," Scientific Reports, vol. 9, No. 256, 2019.
Hyekyoung Lee, Hyejin Kang, Moo K. Chung, Seonhee Lim, Bung-Nyun Kim, and Dong Soo Lee (2016), "Integrated multimodal network approach to PET and MRI based on multidimensional persistent homology," Human Brain Mapping, vol. 38, pp. 1387–1402, Mar. 2017.
Hyekyoung Lee, Moo K. Chung, Hyejin Kang, Bung-Nyun Kim, and Dong Soo Lee (2011), "Persistent brain network homology from the perspective of dendrogram," IEEE Transactions on Medical Imaging, vol. 31, pp. 2267-2277, Dec. 2012. [errata][toy example]
Hyekyoung Lee, Dong Soo Lee, Hyejin Kang, Bung-Nyun Kim, and Moo K. Chung (2010), "Sparse brain network recovery under compressed sensing," IEEE Transactions on Medical Imaging, vol. 30, pp. 1154-1165, May 2011. [errata] [matlab code]
Hyekyoung Lee, Jiho Yoo, and Seungjin Choi (2009), "Semi-supervised nonnegative matrix factorization," IEEE Signal Processing Letters, vol. 17, no. 1, pp. 4-7, January 2010.
Hyekyoung Lee, Andrzej Cichocki, and Seungjin Choi (2009), "Kernel nonnegative matrix factorization for spectral EEG feature extraction," Neurocomputing, vol. 72, pp. 3182-3190, August 2009.
Andrzej Cichocki, Yoshikazu Washizawa, Tomasz Rutkowski, Hovagim Bakardjian, Anh-Huy Phan, Seungjin Choi, Hyekyoung Lee, Qibin Zhao, Liqing Zhang, and Yuanqing Li (2008), "Noninvasive BCIs: Multiway signal-processing array decompositions," IEEE Computer, vol. 41, no. 10, pp. 34-42, October 2008.
Andrzej Cichocki, Hyekyoung Lee, Yong-Deok Kim, and Seungjin Choi (2008), "Nonnegative matrix factorization with alpha-divergence," Pattern Recognition Letters, vol. 29, no. 9, pp. 1433-1440, July 2008.
Hyekyoung Lee, Yong-Deok Kim, Andrzej Cichocki, and Seungjin Choi (2007), "Nonnegative tensor factorization for continuous EEG classification," International Journal of Neural Systems, vol. 17, no. 4, pp. 305-317, August 2007.
Peer Reviewed Conference Papers
Hyekyoung Lee, Moo K. Chung, Hongyoon Choi, Hyejin Kang, Seunggyun Ha, Yu Kyeong Kim, Dong Soo Lee, ''Harmonic holes as the submodules of brain network and network dissimilarity,'' International Workshop on Computational Topology in Image Context (CTIC) 2019, LNCS 11382, pp. 110-122, 2019.
Zachery Morrissey, Liang Zhan, Hyekyoung Lee, Johnson Keiriz, Angus Forbes, Olusola Ajilore, Alex Leow, Moo K. Chung, ''Phase Angle Spatial Embedding (PhASE),'' International Conference on Medical Image Computing and Computer-Assisted Intervention (MICCAI) 2018, LNCS 11072, pp. 367-374, 2018.
Hyekyoung Lee, Moo K. Chung, Hyejin Kang, Hongyoon Choi, Yu Kyeong Kim, Dong Soo Lee, ''Abnormal hole detection in brain connectivity by kernel density of persistence diagram and Hodge Laplacian,'' 2018 IEEE 15th International Symposium on Biomedical Imaging (ISBI 2018), pp. 22-23, 2018 (selected for oral presentation).
Moo K. Chung, Victoria Villalta-Gil, Hyekyoung Lee, Paul J. Rathouz, Benjamin B. Lahey, and David H. Zald, ''Exact Topological Inference for Paired Brain Networks via Persistent Homology," 25th International Conference, Information Processing in Medical Imaging (IPMI), LNCS 10265, pp. 299-310, 2017 (selected for oral presentation).
Hyekyoung Lee, Moo K. Chung, Hyejin Kang, and Dong Soo Lee, ''Hole detection in metabolic connectivity of Alzheimer's disease using k-Laplacian," 17th International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI), vol. 17 (Pt 3), pp. 297-304, 2014.
Moo K. Chung, J. L. Hanson, Hyekyoung Lee, N. Adluru, A. L. Alexander, R. J. Davidson, S. D. Pallak, ''Persistent homological sparse network approach to detecting white matter abnormality in maltreated children: MRI and DTI multimodal study," 16th International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI). Lecture Notes in Computer Science (LNCS) 8149:300-307, 2013 (acceptance 32.8 %).
Hyekyoung Lee, Hyejin Kang, Moo K. Chung, Bung-Nyun Kim, Dong Soo Lee, ``Weighted functional brain network modeling via network filtration," NIPS Workshop on Algebraic Topology and Machine Learning, Reno, U.S.A., December 7-8, 2012.
Hyekyoung Lee, Moo K. Chung, Hyejin Kang, Bung-Nyun Kim, and Dong Soo Lee (2011), "Computing the shape of brain network using graph filtration and Gromov-Haudorff metric," MICCAI2011, Toronto, Canada, September 18-22, 2011 (selected for oral presentation, oral acceptance rate = 4.15 %).
Moo K. Chung, Hyekyoung Lee, Peter T. Kim, and Jong Chul Ye (2010), "Topological data recovery under compressed sensing," IEEE International Symposium on Biomedical Imaging (ISBI), Chicago, U.S.A., March 30 - April 2, 2011.
Hyekyoung Lee, Moo K. Chung, Hyejin Kang, Bung-Nyun Kim, and Dong Soo Lee (2010), "Discriminative persistent homology of brain networks," IEEE International Symposium on Biomedical Imaging (ISBI), Chicago, U.S.A., March 30 - April 2, 2011.
Hyekyoung Lee, Dong Soo Lee, Hyejin Kang, Bung-Nyun Kim, and Moo K. Chung (2010), "Sparse brain network using penalized linear regression," SPIE Medical Imaging, Florida, U.S.A., February 12-17, 2011 (selected for oral presentation).
Hyekyoung Lee, Dong Soo Lee, Hyejin Kang, Boong-Nyun Kim, and Moo K. Chung (2010), "Sparse brain network using penalized linear regression," The 3rd Biennial Symposium on Brain and Mind in the Asia and Pacific (BMAP), Seoul, South Korea, August 23-25, 2010 (selected for oral presentation).
Hyekyoung Lee and Seungjin Choi (2009), "Group nonnegative matrix factorization for EEG classification," in Proceedings of the Twelfth International Conference on Artificial Intelligence and Statistics ( AISTATS-2009 ), Clearwater Beach, Florida, April 16-18, 2009.
Hyekyoung Lee and Seungjin Choi (2007), "CUR+NMF for learning spectral features from large data matrix," in Proceedings of the International Joint Conference on Neural Networks ( IJCNN-2008 ), Hong Kong, June 1-6, 2008
Hyekyoung Lee, Andrzej Cichocki, and Seungjin Choi (2006), "Nonnegative matrix factorization for motor imagery EEG classification," in Proceedings of the International Conference on Artificial Neural Networks (LNCS 4132), Athens, Greece, September 10-14, 2006.
Seongcheol Park, Hyekyoung Lee, and Seungjin Choi (2003), "ICA+OPCA for artifact-robust classification of EEG data," in Proceedings of the IEEE NNSP, pp. 585-594, Toulouse, France, September 17-19, 2003.
Hyekyoung Lee and Seungjin Choi (2003), "PCA+HMM+SVM for EEG pattern classification," in Proceedings of the IEEE ISSPA, pp. 541-544, Paris, France, July 1-4, 2003.
Hyekyoung Lee and Seungjin Choi (2002), "PCA-based linear dynamical systems for multichannel EEG classification," in Proceedings of the ICONIP, pp. 745-749, Singapore, Nov. 19-22, 2002.
Conference Abstracts
Hyekyoung Lee, Moo K. Chung, Hyejin Kang, Hongyoon Choi, Yu Kyeong Kim, and Dong Soo Lee, ''Homological changes of metabolic connectivity during the transition from mild cognitive impairment to Alzheimer's disease," 23th Annual Meeting of the Organization for Human Brain Mapping (OHBM), Vancouver, Canada, June 25-29, 2017.
Hyekyoung Lee, Moo K. Chung, Hyejin Kang, Eunkyung Kim, Youngmin Huh, Jarang Hahm, Yu Kyeong Kim, Dong Soo Lee, ''Shape variability in the dynamics of resting-state functional network and relationship with age," 22th Annual Meeting of the Organization for Human Brain Mapping (OHBM), Geneva, Switzerland, June 26-30, 2016 (selected for oral presentation).
Hyekyoung Lee}, Hyejin Kang, Moo K. Chung, Dong Soo Lee, ''Joint diagonalization of 1-Laplacians for group-wise Brain Network Topology Extraction," 21th Annual Meeting of the Organization for Human Brain Mapping (OHBM), Hawaii, U.S.A., June 14-18, 2015.
Hyekyoung Lee, Hyejin Kang, Moo K. Chung, Dong Soo Lee, ''Aberrant module detection in metabolic network of Alzheimer's disease using higher order Laplacian," 20th Annual Meeting of the Organization for Human Brain Mapping (OHBM), Hamburg, Germany, June 8-12, 2014
Hyekyoung Lee, Hyejin Kang, Moo K. Chung, Eunkyung Kim, Bung-Nyun Kim and Dong Soo Lee (2013),"Metabolic and morphometric brain connectivity by multidimensional persistent homology using PET-MR," 19th Annual Meeting of the Organization for Human Brain Mapping (OHBM), Seattle, U.S.A., June 16-20, 2013.
Hyekyoung Lee, Hyejin Kang, Moo K. Chung, Bung-Nyun Kim and Dong Soo Lee (2012), "Weighted functional brain network modeling via network filtration," NIPS workshop on Algebraic Topology and Machine Learning, Reno, U.S.A., December 1-8.
Hyekyoung Lee, Moo K. Chung, Hyejin Kang, Bung-Nyun Kim and Dong Soo Lee (2012), "Edge selection method preserving the topological features of brain network," 18th Annual Meeting of the Organization for Human Brain Mapping (HBM), Beijing, China, June 10-14, 2012 (selected for oral presentation and NIH travel award).
Hyekyoung Lee, Seung-Goo Kim, Moo K. Chung, Jamie L. Hanson, Brian B. Avants, James C. Gee, Richard J. Davidson and Seth D. Pollak (2011), "Agreement between the white matter connectivity via tensor-based morphometry and the volumetric white matter parcellations," in Nanosymposium at the Society for Neuroscience, Washington, DC, U.S.A., November 12-16, 2011 (selected for oral presentation).
Hyekyoung Lee, Moo K. Chung, Hyejin Kang, Bung-Nyun Kim and Dong Soo Lee (2011), "Persistent network homology from the perspective of dendrograms," 17th Annual Meeting of the Organization for Human Brain Mapping (HBM), Quebec City, Canada, June 26-30, 2011 (selected for oral presentation and NIH travel award).
Hyekyoung Lee, Moo K. Chung, Hyejin Kang, Boong-Nyun Kim, and Dong Soo Lee (2011), "Brain network from sparse and topological point of view," 17th Annual Meeting of the Organization for Human Brain Mapping (HBM), Quebec City, Canada, June 26-30, 2011.
Hyekyoung Lee, Hyojin Park, Hyejin Kang, Moo K. Chung, Eunjoo Kang, June Sic Kim, Chun-Kee Chung, and Dong Soo Lee (2010), "Connectivities between spectral and spatial co-clusters of MEG signal using nonnegative matrix tri-factorization," in Nanosymposium at the Society for Neuroscience, San Diego, November 13-17, 2010 (selected for oral presentation).
Hyojin Park, Hyekyoung Lee, Eunjoo Kang, June Sic Kim, Chun-Kee Chung, and Dong Soo Lee (2010), "Nonnegative tensor factorization for spectral MEG working memory vs. non-memory process," in Neuroscience 2009 - Nanosymposium, Chicago, October 17-21, 2009 (selected for oral presentation).