People

Timothy Tsai

For the past 25 years, I have been involved with research into the reliability of many aspects of computing systems, including general computing systems, supercomputers, telecommunications systems, automotive systems, and storage subsystems.  My current work focuses on the reliable use of Nvidia processors, software, and systems, particularly for HPC and automotive uses.

Research Area(s)
Computer Architecture
High Performance Computing
Resilience and Safety
Main Field of Interest
Resilience and Safety
Google Scholar
https://scholar.google.com/citations?hl=en&user=8Sc8zy8AAAAJ&view_op=list_works…

Publications

2022

Towards Precision-Aware Fault Tolerance Approaches for Mixed-Precision Applications
Bo Fang, Siva Hari, Timothy Tsai, Xinyi Li, Ganesh Gopalakrishnan, Ignacio Laguna, Kevin Barker, Ang Li
Workshop on Fault-Tolerance for HPC at Extreme Scale (FTXS)
Zhuyi: Perception Processing Rate Estimation for Safety in Autonomous Vehicles
Yu-Shun Hsiao, Siva Hari, Michał Filipiuk, Timothy Tsai, Michael B. Sullivan, Vijay Janapa Reddi, Vasu Singh, Steve Keckler
Design Automation Conference (DAC)
Exploiting Temporal Data Diversity for Detecting Safety-critical Faults in AV Compute Systems
Saurabh Jha, Shengkun Cui, Timothy Tsai, Siva Hari, Michael B. Sullivan, Zbigniew T. Kalbarczyk, Steve Keckler, Ravishankar K. Iyer
International Conference on Dependable Systems and Networks (DSN)
Zhuyi: Perception Processing Rate Estimation for Safety in Autonomous Vehicles
Yu-Shun Hsiao, Siva Hari, Michał Filipiuk, Timothy Tsai, Michael B. Sullivan, Vijay Janapa Reddi, Vasu Singh, Steve Keckler
arXiv

2021

Optimizing Selective Protection for CNN Resilience
Abdulrahman Mahmoud, Siva Hari, Christopher W. Fletcher, Sarita V. Adve, Charbel Sakr, Naresh Shanbhag, Pavlo Molchanov, Michael B. Sullivan, Timothy Tsai, Steve Keckler
International Symposium on Software Reliability Engineering (ISSRE)
Suraksha: A Framework to Analyze the Safety Implications of Perception Design Choices in AVs
Hengyu Zhao, Siva Hari, Timothy Tsai, Michael B. Sullivan, Steve Keckler, Jishen Zhao
International Symposium on Software Reliability Engineering (ISSRE)
Characterizing and Mitigating Soft Errors in GPU DRAM
Michael B. Sullivan, Nirmal Saxena, Mike O'Connor, Donghyuk Lee, Paul Racunas, Saurabh Hukerikar, Timothy Tsai, Siva Hari, Steve Keckler
International Symposium on Microarchitecture (MICRO)
IEEE Micro Top Picks in Computer Architecture
Generating and Characterizing Scenarios for Safety Testing of Autonomous Vehicles
Zahra Ghodsi, Siva Hari, Iuri Frosio, Timothy Tsai, Alejandro Troccoli, Steve Keckler, Siddharth Garg, Anima Anandkumar
IEEE Intelligent Vehicles Symposium (IV)
Suraksha: A Quantitative AV Safety Evaluation Framework to Analyze Safety Implications of Perception Design Choices
Hengyu Zhao, Siva Hari, Timothy Tsai, Michael B. Sullivan, Steve Keckler, Jishen Zhao
Workshop on Safety and Security of Intelligent Vehicles (SSIV)
NVBitFI: Dynamic Fault Injection for GPUs
Timothy Tsai, Siva Hari, Michael B. Sullivan, Oreste Villa, Steve Keckler
International Conference on Dependable Systems and Networks (DSN)
Simulation Driven Design and Test for Safety of AI Based Autonomous Vehicles
Vasu Singh, Siva Hari, Timothy Tsai, Mandar Pitale
Workshop on Safe Artificial Intelligence for Automated Driving (SAIAD)
Generating and Characterizing Scenarios for Safety Testing of Autonomous Vehicles
Zahra Ghodsi, Siva Hari, Iuri Frosio, Timothy Tsai, Alejandro Troccoli, Steve Keckler, Siddharth Garg, Anima Anandkumar
arXiv
Making Convolutions Resilient via Algorithm-Based Error Detection Techniques
Siva Hari, Michael B. Sullivan, Timothy Tsai, Steve Keckler
IEEE Transactions on Dependable and Secure Computing (TDSC)

2020

GPU-Trident: Efficient Modeling of Error Propagation in GPU Programs
Abdul Rehman Anwer, Guanpeng Li, Karthik Pattabiraman, Michael B. Sullivan, Timothy Tsai, Siva Hari
The International Conference for High Performance Computing, Networking, Storag…
Generating and Characterizing Scenarios for Safety Testing of Autonomous Vehicles
Zahra Ghodsi, Siva Hari, Iuri Frosio, Timothy Tsai, Alejandro Troccoli, Steve Keckler, Siddharth Garg, Anima Anandkumar
IEEE International Workshop on Automotive Reliability & Test (ART)
Generating and Characterizing Scenarios for Safety Testing of Autonomous Vehicles
Zahra Ghodsi, Siva Hari, Iuri Frosio, Timothy Tsai, Alejandro Troccoli, Steve Keckler, Siddharth Garg, Anima Anandkumar
IEEE Automotive Reliability and Test Workshop
AV-FUZZER: Finding Safety Violations in Autonomous Driving Systems
Guangpeng Li, Yiran Li, Saurabh Jha, Timothy Tsai, Michael B. Sullivan, Siva Hari, Zbigniew Kalbarczyk, Ravishankar Iyer
International Symposium on Software Reliability Engineering (ISSRE)
Best Paper award
HarDNN: Fine-Grained Vulnerability Evaluation and Protection for Convolutional Neural Networks
Abdulrahman Mahmoud, Siva Hari, Christopher W. Fletcher, Sarita V. Adve, Charbel Sakr, Naresh Shanbhag, Pavlo Molchanov, Michael B. Sullivan, Timothy Tsai, Steve Keckler
SRC TECHCON
ML-driven Malware that Targets AV Safety
Saurabh Jha, Shengkun Cui, Subho S. Banerjee, James Cyriac, Timothy Tsai, Zbigniew T. Kalbarczyk, Ravishankar K. Iyer
International Conference on Dependable Systems and Networks (DSN)
Making Convolutions Resilient via Algorithm-Based Error Detection Techniques
Siva Hari, Michael B. Sullivan, Timothy Tsai, Steve Keckler
arXiv
Estimating Silent Data Corruption Rates Using a Two-Level Model
Siva Hari, Paolo Rech, Timothy Tsai, Mark Stephenson, Arslan Zulfiqar, Michael B. Sullivan, Philip Shirvani, Paul Racunas, Joel Emer, Steve Keckler
arXiv
ML-driven Malware that Targets AV Safety
Saurabh Jha, Shengkun Cui, Subho S. Banerjee, James Cyriac, Timothy Tsai, Zbigniew T. Kalbarczyk, Ravishankar K. Iyer
arXiv
Feature Map Vulnerability Evaluation in CNNs
Abdulrahman Mahmoud, Siva Hari, Christopher W. Fletcher, Sarita V. Adve, Charbel Sakr, Naresh Shanbhag, Pavlo Molchanov, Michael B. Sullivan, Timothy Tsai, Steve Keckler
Workshop on Secure and Resilient Autonomy
HarDNN: Feature Map Vulnerability Evaluation in CNNs
Abdulrahman Mahmoud, Siva Hari, Christopher W. Fletcher, Sarita V. Adve, Charbel Sakr, Naresh Shanbhag, Pavlo Molchanov, Michael B. Sullivan, Timothy Tsai, Steve Keckler
arXiv

2019

Kayotee: A Fault Injection-based System to Assess the Safety and Reliability of Autonomous Vehicles to Faults and Errors
Saurabh Jha, Timothy Tsai, Siva Hari, Michael B. Sullivan, Zbigniew Kalbarczyk, Steve Keckler, Ravishankar K. Iyer
arXiv
ML-based Fault Injection for Autonomous Vehicles: A Case for Bayesian Fault Injection
Saurabh Jha, Subho S. Banerjee, Timothy Tsai, Siva Hari, Michael B. Sullivan, Zbigniew T. Kalbarczyk, Steve Keckler, Ravishankar K. Iyer
arXiv
GPU Snapshot: Checkpoint Offloading for GPU-Dense Systems
Kyushick Lee, Michael B. Sullivan, Siva Hari, Timothy Tsai, Steve Keckler, Mattan Erez
International Conference on Supercomputing
ML-based Fault Injection for Autonomous Vehicles: A Case for Bayesian Fault Injection
Saurabh Jha, Subho Banerjee, Timothy Tsai, Siva Hari, Michael B. Sullivan, Zbigniew T. Kalbarczyk, Steve Keckler, Ravishankar K. Iyer
International Conference on Dependable Systems and Networks (DSN)
On the Trend of Resilience for GPU-Dense Systems
Kyushick Lee, Michael B. Sullivan, Siva Hari, Timothy Tsai, Steve Keckler, Mattan Erez
International Conference on Dependable Systems and Networks, Supplemental (DSN-…
Best of SELSE (Workshop on Silicon Errors in Logic - System Effects)
On the Trend of Resilience for GPU-Dense Systems
Kyushick Lee, Michael B. Sullivan, Siva Hari, Timothy Tsai, Steve Keckler, Mattan Erez
IEEE Workshop on Silicon Errors in Logic – System Effects (SELSE)
Award paper
Towards Analytically Evaluating the Error Resilience of GPU Programs
Abdul Rehman Anwer, Guanpeng Li, Karthik Pattabiraman, Siva Hari, Michael B. Sullivan, Timothy Tsai
IEEE Workshop on Silicon Errors in Logic – System Effects (SELSE)

2018

Optimizing Software-Directed Instruction Replication for GPU Error Detection
Abdulrahman Mahmoud, Siva Hari, Michael B. Sullivan, Timothy Tsai, Steve Keckler
International Conference for High-Performance Computing, Networking, Storage a…
Kayotee: A Fault Injection-based System to Assess the Safety and Reliability of Autonomous Vehicles to Faults and Errors
Saurabh Jha, Timothy Tsai, Siva Hari, Michael B. Sullivan, Zbigniew Kalbarczyk, Steve Keckler, Ravishankar K. Iyer
Third IEEE International Workshop on Automotive Reliability & Test
SwapCodes: Error Codes for Hardware-Software Cooperative GPU Pipeline Error Detection
Michael B. Sullivan, Siva Hari, Brian Zimmer, Timothy Tsai, Stephen W. Keckler
The International Symposium on Microarchitecture (MICRO)
Modeling Soft Error Propagation in Programs
Guanpeng Li, Karthik Pattabiraman, Siva Hari, Michael B. Sullivan, Timothy Tsai
International Conference on Dependable Systems and Networks (DSN)

2017

Understanding Error Propagation in Deep Learning Neural Network (DNN) Accelerators and Applications
Guanpeng Li, Siva Hari, Michael B. Sullivan, Timothy Tsai, Karthik Pattabiraman, Joel Emer, Steve Keckler
The International Conference for High Performance Computing, Networking, Storag…
SASSIFI: An Architecture-level Fault Injection Tool for GPU Application Resilience Evaluation
Siva Hari, Timothy Tsai, Mark Stephenson, Steve Keckler, Joel Emer
International Symposium on Performance Analysis of Systems and Software (ISPASS)

2016

An Analytical Model for Hardened Latch Selection and Exploration
Michael B. Sullivan, Brian Zimmer, Siva Hari, Timothy Tsai, Steve Keckler
Workshop on Silicon Errors in Logic--System Effects (SELSE)

2015

SASSIFI: Evaluating Resilience of GPU Applications
Siva Hari, Timothy Tsai, Mark Stephenson, Steve Keckler, Joel Emer
Workshop on Silicon Errors in Logic - System Effects (SELSE-11)

2014

Measuring the Radiation Reliability of SRAM Structures in GPUs Designed for HPC
Paolo Rech, Luigi Carro, Nicholas Wang, Timothy Tsai, Siva Hari, Steve Keckler
Workshop on Silicon Errors in Logic - System Effects (SELSE-10)