I am a hardware engineer at Qualcomm, working on AI/ML accelerator microarchitecture and performance for the Adreno GPU — including the design of a new matrix core IP and its performance modeling. I earned my Ph.D. at KAIST under Prof. Hoi-Jun Yoo, where I designed energy-efficient DNN accelerators across 5 silicon tapeouts (first-author JSSC / MICRO / VLSI / HotChips), and interned at Meta on circuit-architecture co-design for AR/VR.
I am a recipient of the Best Research Achievement Award at KAIST. My current focus is AI/ML accelerator architecture and performance, spanning GPU matrix/tensor cores, dataflow, and performance modeling.
Mobile DRL Accelerator (VLSI 2021)
Mobile Super-Resolution Accelerator (VLSI 2019)
Meta, Ph.D. Research Scientist Intern
LLM workload analysis for 3D stacked memory use case study for AR/VR device
Acknowledged in "Enabling On-Device Large Language Models with 3D-Stacked Memory", NIPSW 2025
(Manager: Huichu Liu)
Reported on national broadcast and government news (South Korea)
DRL accelerator project for mobile devices
Invited Talk: Electronic & Information Research Information Center (EIRIC)
A Deep Reinforcement Learning Accelerator Design with Dual-mode Weight Compression and Floating-point Computing-in-Memory Architecture
May. 2022 ~ Sep. 2022
Jul. 2021
Nov. 2021
Journal Reviewer
IEEE Journal on Emerging and Selected Topics in Circuits and Systems (JETCAS)
IEEE Transactions on Circuits and Systems I: Regular Papers (TCAS-I)
IEEE Proceedings of the IEEE
IEEE Open Journal of the Solid-State Circuits Society (OJ-SSCS)
IEEE Solid-State Circuits Letters (SSCL)
Korea Advanced Institute of Science and Technology (KAIST)
Ph.D. in Electrical Engineering (Advisor: Hoi-Jun Yoo)
Korea Advanced Institute of Science and Technology (KAIST)
M.E. in Electrical Engineering (Advisor: Hoi-Jun Yoo)
Korea Advanced Institute of Science and Technology (KAIST)
B.E. in Electrical Engineering with Summa Cum Laude (GPA 4.05/4.3)
Mar. 2019 ~ Feb. 2023
Mar. 2017 ~ Feb. 2019
Mar. 2013 ~ Feb. 2017
Scholarships and Awards
Best Research Achievement Award (Kim Choong-Ki Award)
Korea Foundation for Advanced Studies, Undergraduate Student Scholarship Program
Young-Han Kim Global Leader Scholarship
Dean’s List In Recognition of Outstanding Scholastic Achievement
Apr. 2022
Mar. 2013 ~ Feb. 2017
Mar. 2015 ~ Aug. 2016
Mar. 2014
Hardware Architecture
GPU matrix/tensor core
Performance modeling
Deep neural network (Deep RL, CNN) accelerator
Programming Languages
Verilog HDL, C/C++, MATLAB, Python
Deep Learning Framework
Pytorch, Tensorflow, MatconvNet
EDA Tools
Synopsys Design Compiler, IC Compiler, IC Compiler II, Cadence, Intel FPGA Design Tool Chain
Technology Experience
TSMC 4nm / 3nm; Samsung 65nm, 28nm Bulk, 28nm FD-SOI
2022
OmniDRL: An Energy-Efficient Deep Reinforcement Learning Processor With Dual-Mode Weight Compression and Sparse Weight Transposer
Juhyoung Lee, Sangyeob Kim, Sangjin Kim, Wooyoung Jo, Jihoon Kim, Donghyeon Han, and Hoi-Jun Yoo
IEEE Journal of Solid-State Circuits (JSSC), 2022
ECIM: Exponent Computing in Memory for an Energy-Efficient Heterogeneous Floating-Point DNN Training Processor
Juhyoung Lee, Jihoon Kim, Wooyoung Jo, Sangyeob Kim, Sangjin Kim,and Hoi-Jun Yoo
IEEE Micro, 2022
Low-power Autonomous Adaptation System with Deep Reinforcement Learning
Juhyoung Lee, Wooyoung Jo, Seong-Wook Park, and Hoi-Jun Yoo
IEEE International Conference on Artificial Intelligence Circuits and Systems (AICAS), 2022
2021
OmniDRL: A 29.3 TFLOPS/W Deep Reinforcement Learning Processor with Dual-mode Weight Compression and On-chip Sparse Weight Transposer "Selected as Technical Highlighted Paper (Circuit Highlights)"
Juhyoung Lee, Sangyeob Kim, Sangjin Kim, Wooyoung Jo, Donghyeon Han, Jinsu Lee, and Hoi-Jun Yoo
IEEE Symposium on VLSI Circuits (VLSI), 2021
A 13.7 TFLOPS/W Floating-point DNN Processor using Heterogeneous Computing Architecture with Exponent-Computing-in-Memory "Selected as 20 most popular on-demand videos"
Juhyoung Lee, Jihoon Kim, Wooyoung Jo, Sangyeob Kim, Sangjin Kim, Jinsu Lee, and Hoi-Jun Yoo
IEEE Symposium on VLSI Circuits (VLSI), 2021
OmniDRL: An Energy-Efficient Mobile Deep Reinforcement Learning Accelerators with Dual-mode Weight Compression and Direct Processing of Compressed Data
Juhyoung Lee, Sangyeob Kim, Jihoon Kim, Sangjin Kim, Wooyoung Jo, Donghyeon Han, and Hoi-Jun Yoo
IEEE HOT Chips: A Symposium on High Performance Chips, 2021
An Energy-efficient Floating-Point DNN Processor using Heterogeneous Computing Architecture with Exponent-Computing-in-Memory
Juhyoung Lee, Jihoon Kim, Wooyoung Jo, Sangyeob Kim, Sangjin Kim, Donghyeon Han, Jinsu Lee, and Hoi-Jun Yoo
IEEE HOT Chips: A Symposium on High Performance Chips, 2021
Energy-Efficient Deep Reinforcement Learning Accelerator Designs for Mobile Autonomous Systems
Juhyoung Lee, Changhyeon Kim, Donghyeon Han, Sangyeob Kim, Sangjin Kim, and Hoi-Jun Yoo
IEEE International Conference on Artificial Intelligence Circuits and Systems (AICAS), 2021
GST: Group-Sparse Training for Accelerating Deep Reinforcement Learning
Juhyoung Lee, Sangyeob Kim, Jihoon Kim, Sangjin Kim, Wooyoung Jo, and Hoi-Jun Yoo
Arxiv, 2021
2020
SRNPU: An Energy-Efficient CNN-Based Super-Resolution Processor With Tile-Based Selective Super-Resolution in Mobile Devices
Juhyoung Lee, Jinsu Lee, and Hoi-Jun Yoo
IEEE Journal on Emerging and Selected Topics in Circuits and Systems (JETCAS), 2020
2019
A Full HD 60 fps CNN Super Resolution Processor with Selective Caching based Layer Fusion for Mobile Devices
Juhyoung Lee, Dongjoo Shin, Jinsu Lee, Jinmook Lee, Sanghoon Kang, and Hoi-Jun Yoo
IEEE Symposium on VLSI Circuits (VLSI), 2019
A 99.4 fps Optical Flow Estimation Processor with Image Tiling for Action Recognition in Mobile Devices
Juhyoung Lee, Sungpill Choi, Jinmook Lee, Sanghoon Kang, and Hoi-Jun Yoo
Journal of Semiconductor Technology and Science (JSTS), 2019
2018
A 46.1 fps Global Matching Optical Flow Estimation Processor for Action Recognition in Mobile Devices
Juhyoung Lee, Changhyeon Kim, Sungpill Choi, Dongjoo Shin, Sanghoon Kang, and Hoi-jun Yoo
IEEE International Symposium on Circuits and Systems (ISCAS), 2018
2022
A Low-Power Graph Convolutional Network Processor with Sparse Grouping for 3D Point Cloud Semantic Segmentation in Mobile Devices
Sangjin Kim, Sangyeob Kim, Juhyoung Lee, and Hoi-Jun Yoo
IEEE Transactions on Circuits and Systems I: Regular Papers (TCAS-I), 2022
TSUNAMI: Triple Sparsity-Aware Ultra Energy-Efficient Neural Network Training Accelerator With Multi-Modal Iterative Pruning
Sangyeob Kim, Juhyoung Lee, Sanghoon Kang, Donghyeon Han, Wooyoung Jo, and Hoi-Jun Yoo
IEEE Transactions on Circuits and Systems I: Regular Papers (TCAS-I), 2022
HNPU-V2: A 46.6 FPS DNN Training Processor for Real-World Environmental Adaptation based Robust Object Detection on Mobile Devices
Donghyeon Han, Dongseok Im, Gwangtae Park, Youngwoo Kim, Seokchan Song, Juhyoung Lee, and Hoi-jun Yoo
IEEE HOT Chips: A Symposium on High Performance Chips, 2022
SNPU: Always-on 63.2μW Face Recognition Spike Domain Convolutional Neural Network Processor with Spike Train Decomposition and Shift-and-Accumulation Unit
Sangyeob Kim, Sangjin Kim, Soyeon Um, Soyeon Kim, Juhyoung Lee, and Hoi-Jun Yoo
IEEE Asian Solid-State Circuits Conference (A-SSCC), 2022
A 0.95 mJ/frame DNN Training Processor for Robust Object Detection with Real-World Environmental Adaptation
Donghyeon Han, Dongseok Im, Gwangtae Park, Youngwoo Kim, Seokchan Song, Juhyoung Lee, and Hoi-Jun Yoo
IEEE International Conference on Artificial Intelligence Circuits and Systems (AICAS), 2022
A 161.6 TOPS/W Mixed-Mode Computing-in-Memory Processor for Energy-Efficient Mixed-Precision Deep Neural Networks
Wooyoung Jo, Sangjin Kim, Juhyoung Lee, Soyeon Um, Zhiyong Li, and Hoi-Jun Yoo
IEEE International Symposium on Circuits and Systems (ISCAS), 2022
2021
HNPU: An Adaptive DNN Training Processor Utilizing Stochastic Dynamic Fixed-Point and Active Bit-Precision Searching
Donghyeon Han, Dongseok Im, Gwangtae Park, Youngwoo Kim, Seokchan Song, Juhyoung Lee, and Hoi-Jun Yoo
IEEE Journal of Solid-State Circuits (JSSC), 2021
GANPU: An Energy-Efficient Multi-DNN Training Processor for GANs With Speculative Dual-Sparsity Exploitation
Sanghoon Kang, Donghyeon Han, Juhyoung Lee, Dongseok Im, Sangyeob Kim, Soyeon Kim, Junha Ryu, and Hoi-Jun Yoo
IEEE Journal of Solid-State Circuits (JSSC), 2021
Z-PIM: A Sparsity-Aware Processing-in-Memory Architecture With Fully Variable Weight Bit-Precision for Energy-Efficient Deep Neural Networks
Ji-Hoon Kim, Juhyoung Lee, Jinsu Lee, Jaehoon Heo, and Joo-Young Kim
IEEE Journal of Solid-State Circuits (JSSC), 2021
A Mobile DNN Training Processor With Automatic Bit Precision Search and Fine-Grained Sparsity Exploitation
Donghyeon Han, Dongseok Im, Gwangtae Park, Youngwoo Kim, Seokchan Song, Juhyoung Lee, and Hoi-Jun Yoo
IEEE Micro, 2021
PNPU: An Energy-Efficient Deep-Neural-Network Learning Processor With Stochastic Coarse–Fine Level Weight Pruning and Adaptive Input/Output/Weight Zero Skipping
Sangyeob Kim, Juhyoung Lee, Sanghoon Kang, Jinmook Lee, Wooyoung Jo, and Hoi-Jun Yoo
IEEE Solid-State Circuits Letters (SSCL), 2021
PNNPU: A 11.9 TOPS/W High-speed 3D Point Cloud-based Neural Network Processor with Block-based Point Processing for Regular DRAM Access
Sangjin Kim, Juhyoung Lee, Dongseok Im and Hoi-Jun Yoo
IEEE Symposium on VLSI Circuits (VLSI), 2021
PNNPU: A Fast and Efficient 3D Point Cloud-based Neural Network Processor with Block-based Point Processing for Regular DRAM Access
Sangjin Kim, Juhyoung Lee, Dongseok Im, Hoi-jun Yoo
IEEE HOT Chips: A Symposium on High Performance Chips, 2021
An Energy-Efficient Deep Reinforcement Learning FPGA Accelerator for Online Fast Adaptation with Selective Mixed-Precision Re-Training
Wooyoung Jo, Juhyoung Lee, Seunghyun Park, Hoi-Jun Yoo
IEEE Asian Solid-State Circuits Conference (A-SSCC), 2021
An Energy-Efficient Deep Neural Network Training Processor with Bit-Slice-Level Reconfigurability and Sparsity Exploitation
Donghyeon Han, Dongseok Im, Gwangtae Park, Youngwoo Kim, Seokchan Song, Juhyoung Lee, and Hoi-Jun Yoo
IEEE Symposium in Low-Power and High-Speed Chips (COOL CHIPS), 2021
2020
A Power-Efficient CNN Accelerator With Similar Feature Skipping for Face Recognition in Mobile Devices
Sangyeob Kim, Juhyoung Lee, Sanghoon Kang, Jinsu Lee and Hoi-Jun Yoo
IEEE Transactions on Circuits and Systems I: Regular Papers (TCAS-I), 2020
A 1.02-μW STT-MRAM-Based DNN ECG Arrhythmia Monitoring SoC With Leakage-Based Delay MAC Unit
Kyoung-Rog Lee, Jihoon Kim, Changhyeon Kim, Donghyeon Han, Juhyoung Lee, Jinsu Lee, Hongsik Jeong, and Hoi-Jun Yoo
IEEE Solid-State Circuits Letters (SSCL), 2020
GANPU: A 135TFLOPS/W Multi-DNN Training Processor for GANs with Speculative Dual-Sparsity Exploitation
Sanghoon Kang, Donghyeon Han, Juhyoung Lee, Dongseok Im, Sangyeob Kim, Soyeon Kim, Hoi-Jun Yoo
IEEE International Solid-State Circuits Conference (ISSCC), 2020
A 146.52 TOPS/W Deep-Neural-Network Learning Processor with Stochastic Coarse-Fine Pruning and Adaptive Input/Output/Weight Skipping
Sangyeob Kim, Juhyoung Lee, Sanghoon Kang, Jinmook Lee and Hoi-Jun Yoo
IEEE Symposium on VLSI Circuits (VLSI), 2020
Z-PIM: An Energy-Efficient Sparsity Aware Processing-In-Memory Architecture with Fully-Variable Weight Precision
Ji-Hoon Kim, Juhyoung Lee, Jinsu Lee, Hoi-Jun Yoo and Joo-Young Kim
IEEE Symposium on VLSI Circuits (VLSI), 2020
GANPU: A Versatile Many-Core Processor for Training GAN on Mobile Devices with Speculative Dual-Sparsity Exploitation
Sanghoon Kang, Donghyeon Han, Juhyoung Lee, Dongseok Im, Sangyeob Kim, Soyeon Kim, Junha Ryu, and Hoi-Jun Yoo
IEEE HOT Chips: A Symposium on High Performance Chips, 2020
A 54.7 fps 3D Point Cloud Semantic Segmentation Processor with Sparse Grouping Based Dilated Graph Convolutional Network for Mobile Devices
Sangjin Kim, Sangyeob Kim, Juhyoung Lee, and Hoi-Jun Yoo
IEEE International Symposium on Circuits and Systems (ISCAS), 2020
2019
An Energy-Efficient Sparse Deep-Neural-Network Learning Accelerator with Fine-grained Mixed Precision of FP8-FP16
Jinsu Lee, Juhyoung Lee, Donghyeon Han, Jinmook Lee, Gwantae Park, and Hoi-Jun Yoo
IEEE Solid-State Circuits Letters (SSCL), 2019
LNPU: A 25.3TFLOPS/W Sparse Deep-Neural-Network Learning Processor with Fine-Grained Mixed Precision of FP8-FP16
Jinsu Lee, Juhyoung Lee, Donghyeon Han, and Hoi-Jun Yoo
IEEE International Solid-State Circuits Conference (ISSCC), 2019
LNPU: An Energy-Efficient Deep-Neural-Network Training Processor with Fine-Grained Mixed Precision
Jinsu Lee, Juhyoung Lee, Donghyeon Han, and Hoi-Jun Yoo
IEEE HOT Chips: A Symposium on High Performance Chips, 2019
A 15.2 TOPS/W CNN Accelerator with Similar Feature Skipping for Face Recognition in Mobile Devices
Sangyeob Kim, Juhyoung Lee, Sanghoon Kang, Jinsu Lee, and Hoi-Jun Yoo
IEEE International Symposium on Circuits and Systems (ISCAS), 2019
2018
DNPU: An Energy-Efficient Deep Learning Processor with Heterogeneous Multi-Core Architecture
Dongjoo Shin, Jinmook Lee, Jinsu Lee, Juhyoung Lee, and Hoi-Jun Yoo
IEEE Micro, 2018
2017
An Energy-Efficient Deep Learning Processor with Heterogeneous Multi-Core Architecture for Convolutional Neural Networks and Recurrent Neural Networks
Dongjoo Shin, Jinmook Lee, Jinsu Lee, Juhyoung Lee, and Hoi-Jun Yoo
IEEE Symposium in Low-Power and High-Speed Chips (COOL CHIPS), 2017