(With my daughter in Cancun in August 2014) 

   Youngjae Kim (PhD)

     Assistant Professor
     Department of Computer Science and Engineering
     SOGANG University
     Seoul, Republic of Korea         

     Director
     Laboratory for Advanced System Software   

     Email: youkim a.t. sogang.ac.kr   
     Phone:+82-2-705-8933
     Office: AS911
     Address: 35 Baekbeom-ro, Mapo-gu, Seoul, Korea, 04107
Teaching
I am teaching operating systems (undergraduate) and topics in operating systems (graduate) this Fall 2018.
Short Biography
I am an assistant professor (tenure-track) in the Department of Computer Science and Engineering at Sogang University (SOGANG) since September 2016. Before joining SOGANG, I was a research scientist in The US Department of Energy’s Oak Ridge National Laboratory in 2009-2015, exploring system software and architectural challenge of integrating non-volatile memory devices into extreme-scale computing machines from several perspectives including memory extension, burst buffers, out-of-core data analytics, and fault tolerance for extreme compute and data system, an adjunct professor in the School of Electrical and Computer Engineering at Georgia Tech, and an assistant professor in the Department of Software at Ajou University. Prior to that, I participated in several file and storage, and data center’s energy management projects at Penn State and embedded operating system projects at ETRI. I completed my Ph.D. in Computer Science and Engineering at Penn State as a member of Computer Systems Laboratory (CSL) under the guidance of Prof. Anand Sivasubramaniam and Prof. Bhuvan Urgaonkar. I received my M.S. from KAIST and B.S. from Sogang University in both computer science. 
Students
I'm fortunate to work with the following wonderful students: 

Current Students 
  1. Awais Khan (Ph.D. student) (2015-)
  2. Chang-Gyu Lee (Ph.D. student) (2015-)
  3. Safdar Jamil (Ph.D. student) (2018-)
  4. Hyeongu Kang (Ph.D. student) (2018-)
  5. Hyunki Byun (M.S. student) (2017-)
  6. Taeuk Kim (M.S. student) (2017-)
  7. Donghyun Min (M.S. student) (2017-)
  8. Donggyu Park (M.S. student) (2017-), co-advised with Prof. Sungyong Park
  9. Jangwoong Kim (M.S. student) (2017-), co-advised with Prof. Sungyong Park 
  10. Sunghyun Noh (M.S. student) (2018-)
  11. Jinwoo Ahn (M.S. student) (2018-)
  12. Yongkyuk Yoo (B.S. student) (2018-)
  13. Joongeon Park (B.S.) (2018-)
  14. Youngwoo Ko (B.S. student) (2018-)
  15. Jiyoon Park (B.S. student) (2018-)
Students at Ajou University 
  1. Preethika Kasu (Ph.D. student) (2016-), co-advised with Tae-Sun Chung at Ajou University 
  2. Prince Hamandawana (Ph.D. student) (2016-), co-advised with Tae-Sun Chung at Ajou University 
Alumni (with first employment) 
  1. Amol Jaikar (Postdoc, 2018), Application Engineer, Brookhaven National Laboratory, USA
  2. Ronnie Mativenga (MS student, 2015-2017), Ph.D. program in Computer Engr., Ajou Univ.   
Research Interest
Distributed Computing and Systems, Operating Systems, File and Storage Systems, Computer System Security
Selected Publications (Full List of Publications)
[CAL'18] Amoeba: An Autonomous Backup and Recovery SSD for Ransomware Defense
Donghyun Min, Donggyu Park, Jinwoo Ahn, Ryan Walker, Junghee Lee, Sungyong Park, Youngjae Kim
IEEE Computer Architecture Letter (CAL) (accepted)

[TPDS'18] An Analysis Workflow-Aware Storage System for Multi-Core Active Flash Arrays
Hyogi Sim, Geoffroy Vall ´ee, Youngjae Kim, Sudharshan Vazhkudai, Devesh Tiwari, Ali Butt
IEEE Transactions on Parallel and Distributed Systems (TPDS) (2018) (accepted) 

[MASCOTS'18] A Robust Fault-Tolerant and Scalable Cluster-wide Deduplication for Shared-Nothing Storage Systems
Awais Khan, Chang-Gyu Lee, Prince Hamandawana, Sungyong Park, Youngjae Kim
Proceedings of the IEEE Int'l Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS) (2018), Milwaukee, WI, USA, September 25-28, 2018. [paper] [talk]

[SC'17] TagIt: An Integrated Search and Discovery Service for File Systems
Hyogi Sim, Youngjae Kim, Sudharshan S. Vazhkudai, Geoffroy R. Valle ́e, Seung-Hwan Lim, Ali R. Butt
Proceedings of the 2017 ACM/IEEE International Conference on High Performance Computing, Networking, Storage and Analysis (SC) (2017), Denver, CO, November, 2017. (Acceptance Rate: 61/327 = 18.9%) [paper] [talk]

[SC'17] Understanding Object-level Memory Access Patterns Across the Spectrum: Are HPC Applications Any Different? 
Xu Ji, Chao Wang, Nosayba El-Sayed, Xiaosong Ma, Youngjae Kim, Sudharshan Vazhkudai, Wei Xue, Daniel Sanchez
Proceedings of the 2017 ACM/IEEE International Conference on High Performance Computing, Networking, Storage and Analysis (SC) (2017), Denver, CO, November, 2017. (Acceptance Rate: 61/327 = 18.9%) [paper] [talk]

[HotStorage'17] Vulnerability Analysis of On-Chip Access-Control Memory
Chintan Chavda, Ethan C. Ahn, Yu-Sheng Chen, Youngjae Kim, Kalidas Ganesh, Junghee Lee
Proceedings of the 9th USENIX Workshop on Hot Topics in Storage and File Systems (HotStorage), Santa Clara, CA, July 10-11, 2017. (Acceptance Rate: 21/51 = 41.1%) [paper] [talk]

[CCGrid'17] AnalyzeThat: A Programmable Shared-Memory System for an Array of Processing-In-Memory Devices
Sangkeun Lee, Hyogi Sim, Youngjae Kim, Sudharshan Vazhkudai
IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGRID) (2017), Madrid, Spain, May 2017.

[TC'17] LAWC: Optimizing Write Cache using Layout-Aware I/O Scheduling for All Flash Storage
Kalidas Ganesh, Youngjae Kim, Monobrata Debnath, Sungyong Park, Junghee Lee
IEEE Transactions on Computers (TC) (2017) Vol. 66, No. 11, pp. 1890-1902, November 2017. [paper]

[TPDS'17] Optimizing End-to-End Big Data Transfers over Terabits Network Infrastructure
Youngjae Kim, Scott Atchley, Geoffroy R. Valle ́e, Matt Lee, Galen M. Shipman
IEEE Transactions on Parallel and Distributed Systems (IEEE TPDS) (2017), Vol. 28, No. 1, pp. 188-201, January 2017. [paper]

[CAL'17] 
FeSSD: A Fast Encrypted SSD Employing On-Chip Access-Control Memory
Junghee Lee, Kalidas Ganesh, Hyuk-Jun Lee, Youngjae Kim
IEEE Computer Architecture Letters (IEEE CAL) (2017), 16(2):115-118 (December 2017). [paper]

[USENIX FAST'15] LADS: Optimizing Data Transfers using Layout-Aware Data Scheduling
Youngjae Kim, Scott Atchley, Geoffroy R. Valle ́e, Galen M. Shipman
Proceedings of the USENIX Conference on File and Storage Technologies (USENIX FAST) (2015), San Jose, CA, February, 2015. (Acceptance Rate: 28/130 = 21.5%) [paper]

[SC'15] AnalyzeThis: An Analysis Workflow-Aware Storage System
Hyogi Sim, Youngjae Kim, Sudharshan Vazhkudai, Devesh Tiwari, Ali Anwar, Ali Butt, Lavanya Ramakrishnan
In Proceedings of the 2015 ACM/IEEE International Conference on High Performance Computing, Networking, Storage and Analysis (SC) (2015), Austin, TX, November, 2015. (Acceptance Rate: 79/358 = 22.0%) [paper]

[SC'15] Best Practices and Lessons Learned from Deploying and Operating Large-Scale Data-Centric Parallel File systems
S. Oral, J. Simmon, J. Hill, D. Leverman, F. Wang, M. Ezell, R. Miller, D. Fuller, R. Gunasekaran, Y. Kim, S. Gupta, D. Tiwari, S. Vazhkudai, J. Rogers, D. Dillow. A. Bland, G. Shipman
Proceedings of the 2015 ACM/IEEE International Conference on High Performance Computing, Networking, Storage and Analysis (SC) (2015), New Orleans, LA, November 16-21, 2014. (Acceptance Rate: 82/394=21.3%) [paper]

[CAL'15] Synchronous I/O Scheduling of Independent Write Caches for an Array of SSDs
Junghee Lee, Youngjae Kim, Jongman Kim, Galen M. Shipman
IEEE Computer Architecture Letters (IEEE CAL) (2015),14(2):79-82 (July 2015). [paper] 

[TC'14] Coordinating Garbage Collection for Arrays of Solid-state Drives
Youngjae Kim, Junghee Lee, Sarp Oral, David Dillow, Feiyi Wang, Galen M. Shipman
IEEE Transactions on Computers (IEEE TC) (2014), Vol. 63, No. 4, pp. 888-901, April 2014. [paper] 

[USENIX FAST'13] Active Flash: Towards Energy-Efficient, In-Situ Data Analytics on Extreme-Scale Machines
Devesh Tiwari, Simona Bobila, Sudharshan Vazhkudai, Youngjae Kim, Xiaosong Ma, Peter Desnoyers, Yan Solin
Proceedings of the USENIX Conference on File and Storage Technologies (USENIX FAST) (2013), San Jose, CA, February, 2013. (Acceptance Rate: 24/127 = 18.9%) [paper] 

[TCAD'13] Preemptible I/O Scheduling of Garbage Collection for Solid-state Drives 
Junghee Lee, Youngjae Kim, Galen M. Shipman, Sarp Oral, Jongman Kim
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems (IEEE TCAD) (2013), Vol. 32, No. 2, pp. 247-260, February 2013. [paper]

[HotPower'12] Reducing Data Movement Costs using Energy-Efficient Active, Computation on SSD
Devesh Tiwari, Sudharshan Vazhkudai, Youngjae Kim, Xiaosong Ma, Simona Boboila, Peter Desnoyers
Proceedings of the USENIX Workshop on Power-Aware Computing and Systems (USENIX HOTPOWER) (2012), co-located with OSDI, Hollywood, CA, October 2012. (Acceptance Rate: 10/39 = 25.6%) [paper]

[Sigmetrics'12] D-Factor: A Quantitative Model of Application Slow-Down in Shared Service Systems with Multiple Resources
Seung-Hwan Lim, Jae-Seok Huh, Youngjae Kim, Galen M. Shipman, Chita Das
Proceedings of the ACM Int'l Conference on Measurement and Modeling of Computer Systems (SIGMETRICS) (2012), London, United Kingdom, June 11-15, 2012. (Acceptance Rate: 31/203 = 15.2%) [paper] [talk]

[IPDPS'12] NVMalloc: Exposing an Aggregate SSD Store as a Memory Partition in Extreme-Scale Machines
Chao Wang, Sudharshan Vazhkudai, Xiaosong Ma, Fei Meng, Youngjae Kim, Christian Engelmann
Proceedings of the IEEE Int'l Parallel and Distributed Processing Symposium (IPDPS) (2012), Shanghai, China, May 21-25, 2012. (Acceptance Rate: 118/569 = 20.7%) [paper]

[MSST'12] Active Flash: Out-of-core Data Analytics on Flash Storage
Simona Boboila, Youngjae Kim, Sudharshan Vazhkudai, Peter Desnoyers, Galen M. Shipman
Proceedings of the IEEE Symposium on Massive Storage Systems and Technologies (MSST) (2012), Monterey, CA, April 16-20, 2012. (Acceptance Rate: 14/57 = 24.5%) [paper] [talk]  

[ICDCS'11] Provisioning a Multi-Tiered Data Staging Area for Extreme-Scale Machines
Ramya Prabhakar, Sudharshan Vazhkudai, Youngjae Kim, Ali Butt, Min Li, Mahmut Kantemir
Proceedings of the International Conference on Distributed Computing Systems (ICDCS) (2011), Minneapolis, Minnesota, June 20-24, 2011. (Acceptance Rate: 87/565 = 15.1%) [paper]

[HotCloud'11] Migration, Assignment, and Scheduling of Jobs in Virtualized Environment
Seung-Hwan Lim, Jae-Seok Huh, Youngjae Kim, Chita Das
Proceedings of the USENIX Workshop on Hot Topics in Cloud Computing (USENIX HOTCLOUD) (2011), co-located with USENIX ATC, Portland, OR, June 2011. (Acceptance Rate: 23/72 = 31.0%) [paper]

[ISPASS'11] A Semi-Preemptive Garbage Collector for Solid State Drives
Junghee Lee, Youngjae Kim, Galen M. Shipman, Sarp Oral, Feiyi Wang, Jongman Kim
Proceedings of the IEEE Int'l Symposium on Performance Analysis of Systems and Software (ISPASS) (2011), Austin, TX, April 10-12, 2011. [paper]

[MSST'11] Harmonia: A Globally Coordinated Garbage Collector for Arrays of Solid-state Drives
Youngjae Kim, Sarp Oral, Galen M. Shipman, Junghee Lee, David Dillow, Feiyi Wang
Proceedings of the IEEE Symposium on Massive Storage Systems and Technologies (MSST) (2011), Denver, Colorado, May 23-27, 2011. (Acceptance Rate: 15/63 = 23.8%) [paper] [talk]

[MASCOTS'11] HybridStore: A Cost-Efficient, High-Performance Storage System Combining SSDs and HDDs
Youngjae Kim, Aayush Gupta, Bhuvan Urgaonkar, Piotr Berman, Anand Sivasubramaniam
Proceedings of the IEEE Int'l Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS) (2011), Singapore, July 25-27, 2011. (Acceptance rate: 41/157 = 26.1%) [paper] [talk]  

[SC'10] Functional Partitioning to Optimize End-to-End Performance on Many-Core Architectures
Min Li, Sudharshan Vazhkudai, Ali Butt, Fei Meng, Xiaosong Ma, Youngjae Kim, Christian Engelmann, Galen M. Shipman, 
Proceedings of the IEEE/ACM Int'l Conference on High Performance Computing, Networking, Storage and Analysis (SC) (2010), New Orleans, LA, November 2010. (Acceptance Rate: 51/253 = 20.1%) [paper]  

[ASPLOS'09] DFTL: A Flash Translation Layer Employing Demand-based Selective Caching of Page-level Address Mappings
Aayush Gupta, Youngjae Kim, and Bhuvan Urgaonkar 
Proceedings of the International Conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS) (2009), Washington DC, March 2009. (Acceptance Rate: 29/113 = 21.8%) [paper]

[SIMUL'09] FlashSim: A Simulator for NAND Flash-based Solid-State Drives
Youngjae Kim, Brendan Tauras, Aayush Gupta, Bhutan Urgaonkar, 
Proceedings of the International Conference on Advances in System Simulation (SIMUL) (2009), Porto, Portugal, September 2009. (Acceptance Rate: 31.0%) [paper]

[TC'08] CFD-based Tool for Studying Temperature in Rack-mounted Servers
Jeonghwan Choi, Youngjae Kim, Anand Sivasubramaniam, Jelena Srebric, Qian Wang, Joonwon Lee,
EEEE Transactions on Computer (TC) (2008), Volume 57, Issue 8, Pages 1129-1142, August 2008. [paper] 

[HPCA'07] Modeling and Managing Thermal Profiles of Rack-mounted Servers with ThermoStat
Jeonghwan Choi, Youngjae Kim, Anand Sivasubramaniam, Jelena Srebric, Qian Wang, Joonwon Lee
Proceedings of the International  Symposium on High Performance Computer Architecture (HPCA) (2007), Phoenix, Arizona, February 2007. (Acceptance Rate: 28/174 = 16.0%) [paper]

[HPCA'06] Understanding the Performance-Temperature Interactions in Disk I/O of Server Workloads
Youngjae Kim, Sudhanva Gurumurthi, Anand Sivasubramaniam
Proceedings of the IEEE Int'l Symposium on High Performance Computer Architecture (HPCA 2006), Austin, Texas, February 2006. (Acceptance Rate: 26/172 = 15.6%) [paper] 
Awards
  • Korea NRF (National Research Foundation) Research Grant for Young Researchers, 2015-2020 (5 years) 
  • Outstanding Research Award, Oak Ridge National Laboratory, 2012
  • Pennsylvania State University Engineering College Scholarship, 2004-2007 (3 years) 
  • Global Korea Scholarship of Ministry of Information and Communication, 2004-2006 (2 years)