"Blessed are the pure in heart, for they shall see God"
- Mat 5:8 -
- [2019.05.14] I will serve IEEE WCNC 2020 as the Demo Chair.
- [2019.03.25] I will serve ACM MobiSys 2019 RisingStar Forum as a TPC member.
- [2019.03.22] I will serve COMSNET 2020 as a TPC member.
- [2019.02.21] I will serve IEEE MASS 2019 as a TPC member.
- [2019.02.18] I will give an invited talk at CPS-IoTBench 2019, a workshop co-located with CPS-IoT Week 2019.
- [2019.02.15] Our paper "ALICE: Autonomous Link-based Cell Scheduling for TSCH" is accepted by ACM/IEEE IPSN 2019.
- [2019.01.27] I will serve ACM SenSys 2019 as a Social-media co-chair.
- [2018.12.26] I will serve IEEE ICCCN 2019 as a TPC member.
- [2018.12.03] I will serve CPS-IoTBench 2019 as a TPC member.
- [2018.11.06] Our paper "System Architecture Directions for Post-SoC/32-bit Networked Sensors" won the Best Paper Runner-up Award at ACM SenSys 2018!
I investigate how to bring performant/standard Internet to the "Internet" of Things. I have been working on standard IoT protocols at all network layers in the light of embedded hardware, operating system, wireless channel, and application characteristics to achieve high throughput, reliability, and low energy together. My research contributions include suggesting system architecture directions for protocol implementation, diagnosing various problems in the IoT protocols, improving the protocols, designing unspecified algorithms and metrics, controlling/optimizing parameters, and investigating killer IoT applications, which are summarized as below:
- System Architecture: Paradigm shift on IoT system architecture considering the latest hardware and application characteristics
- Open source embedded operating systems: Contiki, TinyOS, and RIOT (as a maintainer)
- Standard IoT protocols (layers 1 to 4): Thread/OpenThread, TCP, BLE (Bluetooth Low Energy), RPL, TSCH, WiFi, and IEEE 802.15.4
- Real-world application: Electronic shelf label system for urban marketplaces, Augmented reality-based annotation service
- 45+ publications (8 under review), 5 US patents, 11 Korean patents, 8 awards, and 4 grants
- Diverse collaboration with 50+ peers on three continents (America, Europe, and Asia)
Given that the "Things" side is not the whole world but part of an end-to-end system, my research spans more broadly, including augmented reality, distributed authorization, cellular network, and fog/edge computing.
I love teaching and mentoring, which significantly impact students' future, foster potential collaborators, and often incur a great synergy for my own research. It has been exciting and worthwhile to find each student's own hurdle and help him/her overcome it. My teaching/mentoring can be summarized as follows:
- Instructor: Designing and teaching a graduate course "Embedded Networked Systems for Internet of Things" at UC Berkeley
- Teaching assistant: A graduate course "Advanced Digital Communication" and an undergraduate course "Digital Signal Processing"
- Mentoring: 15+ graduate students and 5+ undergraduate students, resulting in 15+ papers, 4 MS Theses, 4 national grants, and 2 bronze award from Samsung Electronics Human-tech Paper Prize
- [USENIX Security'19] WAVE: A Decentralized Authorization Framework with Transitive Delegation (acceptance ratio: 19%)
- [ACM/IEEE IPSN'19] ALICE: Autonomous Link-based Cell Scheduling for TSCH (acceptance ratio: 27%)
- [ACM SenSys'18, Best Paper Runner-up] System Architecture Directions for Post-SoC/32-bit Networked Sensors (acceptance ratio: 15%)
- [ACM SenSys'18] MARVEL: Enabling Mobile Augmented Reality with Low Energy and Low Latency (acceptance ratio: 15%)
- [ACM UbiComp'18/PACM IMWUT'17] SnapLink: Fast and Accurate Vision-Based Appliance Control in Large Commercial Buildings
- [IEEE COMST'17] Challenging the IPv6 Routing Protocol for Low Power and Lossy Networks (RPL): A Survey (impact factor: 20.23, the highest among all IEEE journals)
- [IEEE DCoSS'17, Best Paper Runner-up] Do Not Lose Bandwidth: Adaptive Transmission Power and Multihop Topology Control
- [IEEE SECON'17] CABLE: Connection Interval Adaptation for BLE in Dynamic Wireless Environments (acceptance ratio: 26%)
- [IEEE CommMag'17] Smarter Markets for Smarter Life: Applications, Challenges and Deployment Experiences (impact factor: 9.27)
- [IEEE TMC'17] Load Balancing under Heavy Traffic in RPL Routing Protocol for Low Power and Lossy Networks (impact factor: 4.098)
- [ACM TOSN'16] Reliable and Energy Efficient Downward Packet Delivery with Asymmetric Transmission Power-based Networks (impact factor: 2.313)
- [IEEE SECON'16] A Synergistic Architecture for RPL over BLE (acceptance ratio: 26%)
- [ACM SenSys'15] MarketNet: An Asymmetric Transmission Power-based Wireless System for Managing e-Price Tags in Markets (acceptance ratio: 20%)
- [IEEE SECON'15] QU-RPL: Queue Utilization based RPL for Load Balancing in Large Scale Industrial Applications (acceptance ratio: 28%)