Publications

77. Myungsik Cho, Jongeui Park, Suyoung Lee and Youngchul Sung*, "Hard task first: Multi-task reinforcement learning through task scheduling," accepted to International Conference on Machine Learning (ICML) 2024

76. Giseung Park, Woohyeon Byeon, Seongmin Kim, Elad Habakuk, Amir Leshem and Youngchul Sung*, "The max-min formulation of multi-objective reinforcement learning: From theory to a model-free algorithm," accepted to International Conference on Machine Learning (ICML) 2024

75. Jeonghye Kim, Suyoung Lee, Woojun Kim*, and Youngchul Sung*, “Decision convformer: Local filtering in metaformer is sufficient for decision making,” International Conference on Learning Representations  (ICLR) , May 2024 

74. Jeonghye Kim, Woojun Kim, and Suyoung Lee, and Youngchul Sung, "Decision convformer: Local filtering in metaformer is sufficient for decision making ," Foundation Model and Decision Making (FMDM) Workshop at NeurIPS 2023, New Orleans, LA, Dec. 2023

73. Woojun Kim+, Yongjae Shin+, Jongeui Park, and Youngchul Sung, "Sample-efficient and safe deep reinforcement learning via reset deep ensemble agents," Conference on Neural Information Processing Systems  (NeurIPS ), New Orleans, LA, Dec. 2023 (+Equal contribution)

72. Sungho Choi, Seungyul Han, Woojun Kim, Jongseong Chae, Whiyoung Jung, and Youngchul Sung, "Domain adaptive imitation learning with visual observation," Conference on Neural Information Processing Systems  (NeurIPS ), New Orleans, LA, Dec. 2023

71. Suyoung Lee, Myungsik Cho, and Youngchul Sung, "Parameterizing Non-Parametric Meta-Reinforcement Learning Tasks via Subtask Decomposition," Conference on Neural Information Processing Systems  (NeurIPS ), New Orleans, LA, Dec. 2023

70. Woojun Kim+, Jeonghye Kim+ and Youngchul Sung, "LESSON: Learning to integrate exploration strategies for reinforcement learning via an option framework," International Conference on Machine Learning (ICML), Hawaii, HI, Jul. 2023 (+Equal contribution)

69. Woojun Kim and Youngchul Sung, "An adaptive entropy regularization framework for multi-agent reinforcement learning," International Conference on Machine Learning (ICML), Hawaii, HI, Jul. 2023

68. Seongmin Kim, Woojun Kim, Jeewon Jeon, Youngchul Sung and Seungyul Han, "Off-policy multi-agent policy optimization with multi-step counterfactual advantage estimation," Adaptive and Learning Agents (ALA) Workshop at AAMAS 2023, London, UK, May 2023 (Non-archival workshop: Submission to other conference allowed)

67. Woojun Kim and Youngchul Sung, “Parameter Sharing with network pruning for scalable multi-agent deep reinforcement learning,” International Conference on Autonomous Agents and Multiagent Systems (AAMAS), London, UK, May 2023

66. Woojun Kim, Whiyoung Jung, Myungsik Cho, and Youngchul Sung, “A variational approach to mutual information-based coordination for multi-agent reinforcement learning,” International Conference on Autonomous Agents and Multiagent Systems (AAMAS), London, UK, May 2023

65. Whiyoung Jung, Myungsik Cho, Jongeui Park and Youngchul Sung, "Quantile constrained reinforcement learning: A reinforcement learning framework constraining outage probability,"  Conference on Neural Information Processing Systems (NeurIPS) 2022,  New Orleans, LA, Nov. 2022

64.  Jongseong Chae, Seungyul Han, Whiyoung Jung, Myungsik Cho, Sungho Choi, and Youngchul Sung, “Robust imitation learning against variations in environment dynamics,” International Conference on Machine Learning (ICML) 2022 , Baltimore, MD, Jul. 2022

63. Jeewon Jeon, Woojun Kim, Whiyoung Jung and Youngchul Sung, “MASER: Multi-agent reinforcement learning with subgoals generated from experience replay buffer,” International Conference on Machine Learning (ICML) 2022 , Baltimore, MD, Jul. 2022

62. Woojun Kim and Youngchul Sung, "An adaptive entropy regularizatio framework for multi-agent reinforcement learning," ICML 2022 Workshop: Decision Awareness in Reinforcement Learning (DARL), Baltimore, MD,Jul. 2022 (Non-archival workshop: Submission to other conference allowed)

61. Woojun Kim, Whiyoung Jung, Myungsik Cho, and Youngchul Sung, “A variational approach to mutual information-based coordination for multi-agent reinforcement learning,” ICML 2022 Workshop: AI for Agent-Based Modelling (AI4ABM), Baltimore, MD,Jul. 2022 (Non-archival workshop: Submission to other conference allowed)

60. Jongeui Park and Youngchul Sung, "Nonlinear rescaling of acquisition metric values based on distribution fitting," ICML 2022 Workshop: Adaptive Experimental Design and Active Learning in the Real World (ReALML), Baltimore, MD, Jul. 2022  (Non-archival workshop: Submission to other conference allowed)

59. Myungsik Cho, Whiyoung Jung, and Youngchul Sung, "Multi-task reinforcement learning with task representation method," ICLR 2022 Workshop on Generalizable Policy Learning in Physical World (GPL),  Apr. 2022

58. Giseung Park, Sungho Choi and Youngchul Sung, "Blockwise sequential model learning for partially observable reinforcement learning," the 36rd AAAI Conference on Artificial Intelligence (AAAI ), Feb. 2022  (Selected as oral presentation)

57. Seungyul Han and Youngchul Sung, "A max-min entropy framework for reinforcement learning," Conference on Neural Information Processing Systems (NeurIPS) 2021, Dec. 2021.

56. Seungyul Han and Youngchul Sung, "Diversity Actor-Critic: Sample-Aware Entropy Regularization for Sample-Efficient Exploration," International Conference on Machine Learning (ICML) 2021,  Jul. 2021

55. Song Noh, Heejung Yu and Youngchul Sung, "Training signal design for sparse channel estimation in millimeter-wave communication with intelligent reflecting surfaces," ICC 2021 Workshop on Reconfigurable Intelligent Surfaces for Future Wireless Communications, Jun. 2021

54. Woojun Kim, Jongeui Park, and Youngchul Sung, "Communication in multi-agent reinforcement learning: Intention sharing," International Conference on Learning Representations (ICLR) 2021, May 2021

53. Whiyoung Jung, Giseung Park, and Youngchul Sung, "Population-Guided Parallel Policy Search for Reinforcement Learning," International Conference on Learning Representations (ICLR) 2020, Vienna, Austria, May 2020

52. Seungyul Han and Youngchul Sung, "AMBER: Adaptive Multi-Batch Experience Replay for Continuous Action Control ," IJCAI Workshop on Scaling Up Reinforcement Learning (SURL), Macao, China, Aug. 2019

51. Seungyul Han and Youngchul Sung, "Dimension-Wise Importance Sampling Weight Clipping for Sample-Efficient Reinforcement Learning," the 36th International Conference on Machine Learning (ICML) 2019, Long Beach, CA, USA, Jun. 2019

50. Woojun Kim, Myungsik Cho, and Youngchul Sung, "Message-dropout: An efficient training method for multi-agent deep reinforcement learning," the 33rd AAAI Conference on Artificial Intelligence (AAAI ) 2019, Honolulu, Hawaii, USA Jan. 2019 

49. G. Park, S. Park, J. Seo, J. So, W. Wang, S. Yoo, S.-C. Lim, J. Chung, M.Cho, D. Ha, J. Kang, H. Park, and Y. Sung, “5G K-Simulator: Link Level Simulator for 5G,” IEEE DySPAN, Seoul, Korea, Oct. 2018

48. Jungho So and Youngchul Sung, “Common pilot signal design for non-orthogonal multiple access in 5G,” IEEE TENCON, Jeju, Korea, Oct. 2018 

47. Whiyoung Jung and Youngchul Sung, “Facial expression classification with universum data,” the 5th International Conference on Robot Intelligence Technology and Applications (RiTA), Daejeon, South Korea, Dec. 2017 

46. Yongjin Kwon, Jihoon Chung, and  Youngchul Sung, “Hybrid beamformer design for mmWave wideband multi-user MIMO-OFDM systems,” Invited Paper to The Special Session of Signal Processing for Millimeter Wave Communication Systems in SPAWC 2017, Sapporo, Japan, Jul. 2017

45. Junyeong Seo and  Youngchul Sung, "A new transceiver architecture for multi-user MIMO communication based on mixture of linear and non-linear reception,” SPAWC 2017, Sapporo, Japan, Jul. 2017

44. Gilwon Lee, Jungho So, and Youngchul Sung, “Impact of training on mmWave multiuser MIMO downlink,” 2016 GlobalSIP, Arlington, VA, Dec. 2016

43. Gilwon Lee and Youngchul Sung, "Random beamforming combined with receive beamforming in mmWave multiuser MIMO downlink,” URSI Asia-Pacific Radio Science Conference, , Seoul, Korea, Aug. 2016

42. Gilwon Lee, Youngchul Sung, and Marios Kountouris, "How can one efficiently schedule users in mmWave massive MIMO?” 2016 IEEE Communication Theory Workshop, Nafplio, Greece, May 2016

41. Gilwon Lee, Youngchul Sung, and Junyeong Seo, "How many users are needed for non-trivial performance of random beamforming in highly-directional mm-wave MIMO downlink?,” 2015 IEEE Information Theory Workshop, Jeju, Korea, Oct. 2015.

40. Gilwon Lee, Youngchul Sung, and Marios Kountouris, "On the performance of randomly directional beamforming between line-of-sight and rich scattering channels,” Invited Paper to The Special Session of Signal Processing for Millimeter Wave Communication Systems in SPAWC 2015, Stockholm, Sweden, Jun. 2015.

39. Junyeong Seo, Youngchul Sung, Gilwon Lee, and Donggun Kim, "Pilot beam sequence design for channel estimation in millimeter-wave MIMO systems: A POMDP framework,” SPAWC 2015, Stockholm, Sweden, Jun. 2015.

38. Sangwoon Kwak, Jungho So, and Youngchul Sung, "An extended least difference greedy clique-cover algorithm for index coding,” ISIT 2014, Hawaii, HI, Jun. 2014.

37. Jungho So, Sangwoon Kwak, and Youngchul Sung, "Some new results on index coding when the number of data is less than the number of receivers,” ISIT 2014, Hawaii, HI, Jun. 2014. Supplement

36. Gilwon Lee and Youngchul Sung, "Asymptotically optimal simple user scheduling for massive MIMO downlink with two-stage beamforming," Proc. of SPAWC 2014, Toronto, CA, Jun. 2014.

35. Song Noh, Michael Zoltowski, Youngchul Sung, and David Love, "Training signal design for channel estimation in massive MIMO systems," Proc. of ICASSP 2014, Florence, Italy, May 2014.

34. Song Noh, Michael Zoltowski, Youngchul Sung, and David Love, "Optimal pilot beam pattern design for massive MIMO systems," in Asilomar Conference on Signals, Systems, and Computers, Pacific Grove, CA, Nov. 2013.

33. Juho Park and Youngchul Sung, "An efficient parameterization for Pareto-optimal beamformers for K-user MIMO interference channels ," in Proc. of ICASSP 2013, Vancouver, Canada, May 2013.

32. Gilwon Lee, Juho Park, Youngchul Sung and Junyeong Seo, "A new approach to beamformer design for massive MIMO systems based on k-regularity," International Workshop on Emerging Technologies for LTE-Advanced and Beyond 4G in conjunction with Globecom 2012, Anaheim, CA, Dec. 2012.

31. Donggun Kim, Junyeong Seo, and Youngchul Sung, "Filter-and-forward relay design for OFDM systems for quality-of-servie enhancement," in Proc. of APSIPA 2012, Hollywood, CA, Dec. 2012.

30. Cheulsoon Kim,  Eui-Rim Jeong, Youngchul Sung and Yong H. Lee, “Asymmetric complex signaling for full-duplex decode-and-forward relay channels,” International Conference on ICT Convergence, Jeju, Korea, Oct. 2012 .

29. Yuni Lee and Youngchul Sung, "'The Bahadur efficiency for energy detection of stationary Gaussian processes"ICASSP 2012, Kyoto, Japan, Mar. 2012.

28. Juho Park, Donggun Kim and Youngchul Sung, "Sum outage rate maximization for MIMO interference channels," in Proc. of Globecom 2011, Houston, TX, Dec. 2011.

27. Gilwon Lee, Juho Park, Youngchul Sung and Masahiro Yukawa, "Coordinated beamforming with relaxed zero forcing," in Proc. of the 2011 International Conference on Wireless Communications and Signal Processing (WCSP), invited paper to the special session "Interference Management Techniques in Wireless Networks," Nov. 2011.

26. M. Yukawa, Y. Sung and G. Lee, "Adaptive interference suppression in MIMO multiple access channels based on dual-domain approach," in Proc. of ITC-CSCC 2011, Gyeongju, Korea, June 2011.

25. J. Lee, H. Yu, Y. Sung and Y. H. Lee, "Adaptive beam tracking for interference alignment in time-varying MIMO interference channels: Conjugate gradient approach," in Proc. of ICASSP 2011, Prague, Czech Republic, May 2011. (The algorithm in this paper is a pure adaptive version of that in the ICASSP 2010 paper below.)

24. S. Noh and Y. Sung, "Precoder design for blind channel estimation in multiple OFDM systems," in Proc. of APSIPA 2010, Singapore, December 2010

23. H. Yu and Y. Sung, "Iterative algorithm for interference alignment in multiuser MIMO interference channels," in SPAWC 2010, Marrakech, Morocco, June 2010. (This is an improved iterative version of the previous algorithm in SPAWC 09.)

22. H. Yu, Y. Sung, H. Kim and Y. H. Lee, "Adaptive beam tracking for interference alignment for multiuser time-varying MIMO interference channels," in Proc. of ICASSP 2010, Dallas, Texas, March 2010

21. H. Yu, J. Park, Y. Sung and Y. H. Lee, "A least squares approach to joint beam design for interference alignment in multiuser interference channels," in Proc. of SPAWC 2009, Perugia, Italy, June 2009

20. Jo Woon Chong, Youngchul Sung and Dan Keun Sung, "Multi-band CSMA/CA-based cognitive radio networks," in Proc. of IWCMC 2009, Leipzig, Germany, June 2009

19. H. Kim, S. Choi, H. Yu, Y. Sung and Y. H. Lee, "Amplify-forward relays with superimposed pilot signals for frequency-selective fading channels,” in Proc. of VTC 2009, Barcelona, Spain, April 2009

18. Yirang Lim and Youngchul Sung, "Upper bound for the loss factor of energy detection of random signals in multipath fading cognitive radios," in Proc. of ICASSP 2009, Taipei, Taiwan, April 2009

17. Heejung Yu, Youngchul Sung and Yong H. Lee, "Superposition data transmission for cognitive radios: Performance and algorithms,"IEEE MILCOM, San Diego, CA, Nov. 2008

16. Jo Woon Chong, Youngchul Sung and Dan Keun Sungm, "Analysis of CSMA/CA systems under carrier sensing error: Throughput, delay and sensitivity,"IEEE Globecom 2008, New Orleans, LA, Nov. 2008

15. Jo Woon Chong, Youngchul Sung and Dan Keun Sung, "Cross-layer performance analysis for CSMA/CA systems: Impact of imperfect sensing," in Proc. of the 9th IEEE Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Recife, Brazil, July 2008

14. Youngchul Sung, H. Vincent Poor and Heejung Yu, "Information, energy and density for ad hoc sensor networks over correlated random fields: Large deviations analysis," in 2008 IEEE International Symposium on Information Theory (ISIT), Toronto, Ontario, Canada, July 2008

13. Youngchul Sung, H. Vincent Poor and Heejung Yu, "Optimal node density for two-dimensional sensor arrays," in Proc. of5th IEEE Workshop on Sensor Array and Multi-Channel Signal Processing (SAM 2008), Darmstadt, Germany, July 2008

12. Y. Sung, H. V. Poor and H. Yu, "Large deviations analysis for the detection of 2-D hidden Gauss-Markov random fields using sensor networks," Proc. of 2008 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Las Vegas, Nevada, March 2008

11. H. Yu, Y. Sung and Y. H. Lee, "On optimal operating characteristics of sensing and training for cognitive radios," Proc. of 2008 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Las Vegas, Nevada, March 2008

10. Y. Sung, L. Tong and A. Ephremides, “A new metric for routing in multi-hop wireless sensor Networks for detection of correlated random fields,” in Proc. of MILCOM’05, Atlantic City, New Jersey, October 2005

9. Y. Sung, L. Tong and H. V. Poor, “Neyman-Pearson detection of Gauss-Markov signals in noise: Closed-form error exponent and properties,” in Proc. of 2005 IEEE International Symposium on Information Theory (ISIT), Adelaide, Australia, September 2005

8. Y. Sung, L. Tong and H. V. Poor,“Optimal and suboptimal detection of Gaussian signals in noise: Asymptotic relative efficiency,” in Proc. of the Conference on Advanced Signal Processing Algorithms, Architectures, and Implementations XV, part of SPIE International Symposium, San Diego, CA, July 2005

7. Y. Sung, L. Tong and A. Ephremides, “Route selection for detection of correlated random fields in large sensor networks,” in Proc. of CISS’05, Johns Hopkins University, Baltimore, MD, March 2005

6. Y. Sung, L. Tong and H. V. Poor, “A large deviations approach to sensor scheduling for detection of correlated random fields,” in Proc. of ICASSP 2005, Philadelphia, PA, March 2005 (ICASSP 2005 Student Best Paper Award)

5. Y. Sung, L. Tong and A. Swami, “Asymptotic locally optimal detector for large-scale sensor networks under the Poisson regime,” in Proc. of 2004 ICASSP, Montreal, QC, Canada, May 2004

4. Y. Sung, L. Tong and A. Swami, “Semi-blind channel estimation for space-time coded WCDMA downlink,” in Proc. of 2003 ICC, Anchorage, AK, May 2003

3. Y. Sung and L. Tong, “Blind channel tracking for long code WCDMA with linear interpolation model,” in Proc. of 2002 Asilomar Conference, Monteray, CA, November 2002

2. Y. Sung and L. Tong, “Channel tracking for long code WCDMA,” in Proc. of 2002 MILCOM, Anaheim, CA, October 2002.

1. Y. Sung and L. Tong, “A projection-based semi-blind channel estimation for long-code WCDMA,” in Proc. of 2002 ICASSP, Orlando, FL, May 2002

19. G. Park, S. Park, J. Seo, J. So, W. Wang, S. Yoo, S. Lim, J. Chung, M. Cho, D. Ha, J. Kang, H. Park, and Y. Sung, "Link-level simulator for 5G NSA," Joint Conference on Communications & Information (JCCI), Yeoseo, May 2018

18. G. Park, S. Park, J. Seo, J. So, W. Wang, S. Yoo, S. Lim, J. Chung, M. Cho, D. Ha, J. Kang, H. Park, and Y. Sung, "Design of modular link-level simulator for 5G," Korean Institute of Communications and Information Sciences (KICS),
Winter Conference, Kwangwon, Jan. 2018

17. W. Kim, G. Park, S. Park, J. Seo, J. So, S. Yoo, S. Lim, J. Chung, D. Ha, J. Kang, H. Park, and Y. Sung, "Development of open-source modular link-level simulator for pre-5G," Korean Institute of Communications and Information Sciences (KICS), Summer Conference, Jeju, Jun. 2017

16. Gilwon Lee, Jungho So, and Youngchul Sung, “A new hierarchical beam training method for millimeter-wave communication,” Joint Conference on Communications & Information (JCCI), Apr. 2017

15. Seungyeol Han and Youngchul Sung, “Filter optimization for generalized frequency division multiplexing,” Joint Conference on Communications & Information (JCCI), Apr. 2016

14. Gilwon Lee and Youngchul Sung, “Improved random beamforming in mmWave channels,” Joint Conference on Communications & Information (JCCI), Apr. 2016

13. Gilwon Lee, Youngchul Sung, Junyeong Seo, “Random beamforming in mmWave channels,” Joint Conference on Communications & Information (JCCI), Apr. 2015

12. Jihoon Chung, Donggun Kim, and Youngchul Sung, “Optimal design of amplify-and-forward helper stations for cellular networks with device-to-device links,” Korean Institute of Communications and Information Sciences (KICS), Fall Conference, Apr. 2014

11. Jihoon Chung, Junyeong Seo, Donggun Kim, Youngchul Sung, “Efficient direction-of-arrival estimation based on mm wave channel modeling,” Joint Conference on Communications & Information (JCCI), Apr. 2014

10. Song Noh and Youngchul Sung, “Linear precoder design for blind channel estimation for MIMO-OFDM systems under a sparse structure,” IEEK 2011 Summer Conference, Jeju, Korea, Jun. 2011

9.  Donggun Kim, Juho Park and Youngchul Sung, “Robust beam design in multi-input multi-output interference channels based on mean square error,” Joint Conference on Communications & Information (JCCI), May 2011

8.  Cheulsoon Kim, Youngchul Sung and Yong H. Lee, “Interference-symbol-based user cooperation scheme,” Joint Conference on Communications & Information (JCCI), May 2011 

7.  Juho Park and Youngchul Sung, “Interference alignment in asymmetric multi-input multi-output interference channels,” Joint Conference on Communications & Information (JCCI), Apr. 2010. (Best Paper Award in JCCI 2010)

6.  Heejung Yu, Youngchul Sung and Yong H. Lee, “Joint optimization of transmit power and operating point of channel sensingfor cognitive radio networks,” Joint Conference on Communications & Information (JCCI), Apr. 2010

5.  Haksoo Kim, Heejung Yu, Youngchul Sung and Yong H. Lee, “Bilinear programming approach to interference alignment,” KICS Fall Workshop, Nov. 2009

4.  Heejung Yu, Juho Park, Youngchul Sung and Yong H. Lee, “A non-iterative approach to beam design for interference alignment for multiuser interference channels,” KICS CITS Workshop, Daejeon, Korea, Feb. 2009

3.  Haksoo Kim, Heejung Yu, Youngchul Sung and Yong H. Lee, “Analysis of point-to-point communication coexisting with OFDM-based cellular systems,” the 12th Communication and Electronics Conference, Seoul, Oct. 2008

2.  Haksoo Kim, Sungho Choi, Youngchul Sung and Yong H. Lee, “AF relay system employing superimposed pilot over frequency-selective channels, Joint Conference on Communications & Information (JCCI), Jeju, Korea, Apr. 2008

1.  Heejung Yu, Youngchul Sung and Yong H. Lee, “Superposition data transmission for secondary users in cognitive radios,” Joint Conference on Communications & Information (JCCI), Jeju, Korea, Apr. 2008