Portrait of Ziyang Song is unavailable

Ziyang Song

PhD - McGill University
Supervisor
Research Topics
Medical Machine Learning

Publications

Jailbreak Distillation: Renewable Safety Benchmarking
Jingyu Zhang
Ahmed Elgohary
Xiawei Wang
A S M Iftekhar
Ahmed Magooda
Benjamin Van Durme
Daniel Khashabi
Kyle Jackson
JBDistill Benchmark JBDistill Benchmark
Marah Ihab Abdin
Jyoti Aneja
Harkirat Singh Behl
Sébastien Bubeck
Ronen Eldan
S. Gunasekar
Michael Harrison
Russell J. Hewett
Mojan Javaheripi
Piero Kauffmann
James R. Lee … (see 484 more)
Yin Tat Lee
Yuanzhi Li
Weishung Liu
Caio C. T. Mendes
Anh Nguyen
Eric Price
Gustavo de Rosa
Olli Saarikivi
Adil Salim
Tim Beyer
Simon Geisler
Stephan Günnemann. 2025
Blake Bullwinkel
Amanda Minnich
Shiven Chawla
Gary Lopez
Martin Pouliot
Whitney Maxwell
Patrick Chao
Edoardo Debenedetti
Alexander Robey
Maksym Andriushchenko
Francesco Croce
Vikash Sehwag
Edgar Dobriban
Nicolas Flammarion
George J. Pappas
Florian Tramèr
Hamed Hassani
Eric Wong
Jailbreakbench
Zora Che
Stephen Casper
Robert Kirk
Anirudh Satheesh
Stewart Slocum
Lev E McKinney
Rohit Gandikota
Aidan Ewart
Domenic Rosati
Zichu Wu
Zikui Cai
Daya Guo
Dejian Yang
Haowei Zhang
Jun-Mei Song
Ruoyu Zhang
Runxin Xu
Qihao Zhu
Shirong Ma
Peiyi Wang
Xiaoling Bi
Xiaokang Zhang
Xingkai Yu
Yu Wu
Z. F. Wu
Zhibin Gou
Zhihong Shao
Zhuoshu Li
Ziyi Gao
A. Liu
Bing Xue
Bingxuan Wang
Bo WU
Bei Feng
Cheng Lu
Chenggang Zhao
Chengqi Deng
Chenyu Zhang
C. Ruan
Damai Dai
Deli Chen
Dong-Li Ji
Erhang Li
Fangyun Lin
Fucong Dai
Fuli Luo
Guangbo Hao
Guanting Chen
Guowei Li
Han Bao
Hanwei Xu
Haocheng Wang
Honghui Ding
Huajian Xin
Huazuo Gao
Hui Qu
Hui Li
Jianzhong Guo
Jiashi Li
Jiawei Wang
Jingchang Chen
Jingyang Yuan
Junjie Qiu
Junlong Li
J. Cai
J. Ni
Jian Liang
Jin Chen
Kai Dong
Kai Hu
Kaige Gao
Kang Guan
Kexin Huang
Kuai Yu
Lean Wang
Lecong Zhang
Liang Zhao
Litong Wang
Liyue Zhang
Lei Xu
Leyi Xia
Mingchuan Zhang
Minghua Zhang
Min Tang
Meng Li
Miaojun Wang
Mingming Li
Ning Tian
Panpan Huang
Peng Zhang
Qiancheng Wang
Qinyu Chen
Qiushi Du
Ruiqi Ge
Ruisong Zhang
Ruizhe Pan
Runji Wang
R. J. Chen
Rong Jin
Ruyi Chen
Shanghao Lu
Shangyan Zhou
Shanhuang Chen
Shengfeng Ye
Shiyu Wang
Shuiping Yu
Shunfeng Zhou
Shuting Pan
S. S. Li
Shuang Zhou
Shao-Ping Wu
Tao Yun
Tian Pei
Tianyu Sun
T. Wang
Wangding Zeng
Wanjia Zhao
Wen Liu
Wenfeng Liang
Wenjun Gao
Wen-Xuan Yu
Wentao Zhang
Wei Xiao
Wei An
Xiaodong Liu
Xiaohan Wang
Xiaokang Chen
Xiaotao Nie
Xin Cheng
Xin Liu
Xinfeng Xie
Xingchao Liu
Xinyu Yang
Xinyuan Li
Xuecheng Su
Xuheng Lin
Xiangyu Jin
Xi-Cheng Shen
Xiaosha Chen
Xiaowen Sun
Xiaoxi-ang Wang
Xinnan Song
Xinyi Zhou
Xianzu Wang
Xinxia Shan
Y. K. Li
Y. Q. Wang
Y. X. Wei
Yang Zhang
Yanhong Xu
Yao Zhao
Yaofeng Sun
Yaohui Wang
Yi Yu
Yichao Zhang
Yifan Shi
Yi Xiong
Ying He
Yishi Piao
Yisong Wang
Yi Chern Tan
Yiyang Ma
Yiyuan Liu
Yongqiang Guo
Yuan Ou
Yuduan Wang
Yue Gong
Yuheng Zou
Yuzi He
Yunfan Xiong
Yuxiang Luo
Yuxiang You
Yu-mei You
Yuxuan Liu
Yuyang Zhou
Y. X. Zhu
Yanping Huang
Yaohui Li
Yao Li
Yi Zheng
Yunxiang Ma
Ying Tang
Yukun Zha
Yuting Yan
Z. Z. Ren
Zehui Ren
Zhangli Sha
Zhe Fu
Zhean Xu
Zhenda Xie
Zhengyan Zhang
Zhewen Hao
Zhicheng Ma
Zhigang Yan
Zhiyu Wu
Zihui Gu
Zijia Zhu
Zijun Liu
Zi-An Li
Ziwei Xie
Deep Ganguli
Liane Lovitt
Jackson Kernion
Amanda Askell
Yuntao Bai
Saurav Kadavath
Benjamin Mann
Ethan Perez
Nicholas Schiefer
Kamal Ndousse
Andy Jones
Sam Bowman
Anna Chen
Tom Con-erly
Nova Dassarma
Dawn Drain
Nelson Elhage Sheer
Stanislav Fort
Zac Hatfield-Dodds
T. Henighan
Danny Hernandez
Tristan Hume
Josh Jacobson
Scott Johnston
Shauna Kravec
Catherine Olsson
Sam Ringer
Eli Tran-Johnson
Dario Amodei
Tom Brown
Nicholas Joseph
Sam McCandlish
Chris Olah
Jared Kaplan
Jack Clark. 2022. Red
Aaron Grattafiori
Abhimanyu Dubey
Abhinav Jauhri
Abhinav Pandey
Abhishek Kadian
Ahmad Al-Dahle
Aiesha Letman
Akhil Mathur
Alan Schel-ten
Alex Vaughan
Amy Yang
Angela Fan
Anirudh Goyal
A. Hartshorn
Aobo Yang
Archi Mitra
Archie Sravankumar
Artem Korenev
Arthur Hinsvark
Arun Rao
Aston Zhang
Aurelien Ro-driguez
Austen Gregerson
Ava Spataru
Baptiste Rozière
Bethany Biron
Binh Tang
Bobbie Chern
Charlotte Caucheteux
Chaya Nayak
Chloe Bi
Chris Marra
Chris McConnell
Christian Keller
Christophe Touret
Chunyang Wu
Corinne Wong
Cris-tian Cantón Ferrer
Cyrus Nikolaidis
Damien Al-lonsius
Daniel Song
Danielle Pintz
Danny Livshits
Danny Wyatt
David Esiobu
Dhruv Choudhary
Dhruv Mahajan 0001
Diego Garcia-Olano
Diego Perino
Dieuwke Hupkes
Egor Lakomkin
Ehab A. AlBadawy
Elina Lobanova
Emily Dinan
Eric Michael Smith
Filip Radenovic
Francisco Guzmán
Frank Zhang
Gabriele Synnaeve
Gabrielle Lee
Georgia Lewis
G. Thattai
Graeme Nail
Gregoire Mi-alon
Guan Pang
Guillem Cucurell
Hailey Nguyen
Han-nah Korevaar
Hu Xu
Hugo Touvron
Imanol Iliyan Zarov
Arrieta Ibarra
Is-abel Kloumann
Ishan Misra
Ivan Evtimov
Jack Zhang
Jade Copet
Jaewon Lee
Jan Geffert
Jana Vranes
Jason Park
Jay Mahadeokar
Jeet Shah
Jelmer van der Linde
Jennifer Billock
Jenny Hong
Jenya Lee
Jeremy Fu
J. Fu
Jianfeng Chi
Jianyu Huang
Jiawen Liu
Jie Wang
Jiecao Yu
Joanna Bitton
Joe Spisak
Jongsoo Park
Joseph Rocca
J. Johnstun
Joshua Saxe
Junteng Jia
Kalyan Vasuden Alwala
Karthik Prasad
Kartikeya Upasani
Kate Plawiak
Keqian Li
K. Heafield
Kevin R. Stone
Khalid El-Arini
Krithika Iyer
Kshitiz Malik
Kuen-ley Chiu
Kunal Bhalla
Kushal Lakhotia
Lauren Rantala-Yeary
Laurens van der Maaten
Lawrence Chen
Liang Tan
Liz Jenkins
Louis Martin
Lovish Madaan
Lubo Malo
Lukas Blecher
Lukas Landzaat
Luke de Oliveira
Madeline Muzzi
Mahesh Pasupuleti
Mannat Singh
Manohar Paluri
Marcin Kardas
Maria Tsimpoukelli
Mathew Oldham
Mathieu Rita
Maya Pavlova
Melanie Kam-badur
Mike Lewis
Mitesh Min Si
Kumar Singh
Mona Hassan
Naman Goyal
Narjes Torabi
Niko-lay Bashlykov
Nikolay Bogoychev
Niladri S. Chatterji
Ning Zhang
Olivier Duchenne
Onur Çelebi
Patrick Alrassy
Petar Pengwei Li
Peter Weng
Prajjwal Bhargava
Pratik Dubal
Punit Praveen Krishnan
Singh Koura
Puxin Xu
Qing He
Qingxiao Dong
Ragavan Srinivasan
Raj Ganapathy
Ramon Calderer
Ricardo Silveira Cabral
Robert Stojnic
Roberta Raileanu
Rohan Maheswari
Rohit Girdhar
Rohit Patel
Ro-main Sauvestre
Ron-nie Polidoro
Roshan Sumbaly
Ross Taylor
Ruan Silva
Rui Hou
Rui Wang
S. Hosseini
Sa-hana Chennabasappa
Sanjay Singh
Sean Bell
Seo-hyun Sonia Kim
Sergey Edunov
Shaoliang Nie
Sharan Narang
Sharath Chandra Raparthy
Sheng Shen
Shengye Wan
Shruti Bhosale
Shun Zhang
Simon Van-denhende
Soumya Batra
Spencer Whitman
Sten Sootla
Stephane Collot
Suchin Gururangan
S. Borodinsky
Tamar Herman
Tara Fowler
Tarek Sheasha
Thomas Georgiou
Thomas Scialom
Tobias Speckbacher
Todor Mihaylov
Tong Xiao
Ujjwal Karn
Vedanuj Goswami
Vibhor Gupta
Vignesh Ramanathan
Viktor Kerkez
Vincent Gonguet
Vir-ginie Do
Vish Vogeti
Vitor Albiero
Vladan Petro-vic
Weiwei Chu
Wenhan Xiong
Wenyin Fu
Extrapolatable Transformer Pre-training for Ultra Long Time-Series Forecasting
Qincheng Lu
Hao Xu
Mike He Zhu
MixEHR-Nest: Identifying Subphenotypes within Electronic Health Records through Hierarchical Guided-Topic Modeling
Ruohan Wang
Zilong Wang
Automatic subphenotyping from electronic health records (EHRs)provides numerous opportunities to understand diseases with unique subgroups a… (see more)nd enhance personalized medicine for patients. However, existing machine learning algorithms either focus on specific diseases for better interpretability or produce coarse-grained phenotype topics without considering nuanced disease patterns. In this study, we propose a guided topic model, MixEHR-Nest, to infer sub-phenotype topics from thousands of disease using multi-modal EHR data. Specifically, MixEHR-Nest detects multiple subtopics from each phenotype topic, whose prior is guided by the expert-curated phenotype concepts such as Phenotype Codes (PheCodes) or Clinical Classification Software (CCS) codes. We evaluated MixEHR-Nest on two EHR datasets: (1) the MIMIC-III dataset consisting of over 38 thousand patients from intensive care unit (ICU) from Beth Israel Deaconess Medical Center (BIDMC) in Boston, USA; (2) the healthcare administrative database PopHR, comprising 1.3 million patients from Montreal, Canada. Experimental results demonstrate that MixEHR-Nest can identify subphenotypes with distinct patterns within each phenotype, which are predictive for disease progression and severity. Consequently, MixEHR-Nest distinguishes between type 1 and type 2 diabetes by inferring subphenotypes using CCS codes, which do not differentiate these two subtype concepts. Additionally, MixEHR-Nest not only improved the prediction accuracy of short-term mortality of ICU patients and initial insulin treatment in diabetic patients but also revealed the contributions of subphenotypes. For longitudinal analysis, MixEHR-Nest identified subphenotypes of distinct age prevalence under the same phenotypes, such as asthma, leukemia, epilepsy, and depression. The MixEHR-Nest software is available at GitHub: https://github.com/li-lab-mcgill/MixEHR-Nest.
Bidirectional Generative Pre-training for Improving Healthcare Time-series Representation Learning
Learning time-series representations for discriminative tasks, such as classification and regression, has been a long-standing challenge in … (see more)the healthcare domain. Current pre-training methods are limited in either unidirectional next-token prediction or randomly masked token prediction. We propose a novel architecture called Bidirectional Timely Generative Pre-trained Transformer (BiTimelyGPT), which pre-trains on biosignals and longitudinal clinical records by both next-token and previous-token prediction in alternating transformer layers. This pre-training task preserves original distribution and data shapes of the time-series. Additionally, the full-rank forward and backward attention matrices exhibit more expressive representation capabilities. Using biosignals and longitudinal clinical records, BiTimelyGPT demonstrates superior performance in predicting neurological functionality, disease diagnosis, and physiological signs. By visualizing the attention heatmap, we observe that the pre-trained BiTimelyGPT can identify discriminative segments from biosignal time-series sequences, even more so after fine-tuning on the task.
TrajGPT: Healthcare Time-Series Representation Learning for Trajectory Prediction
Qincheng Lu
Mike He Zhu
In many domains, such as healthcare, time-series data is irregularly sampled with varying intervals between observations. This creates chall… (see more)enges for classical time-series models that require equally spaced data. To address this, we propose a novel time-series Transformer called **Trajectory Generative Pre-trained Transformer (TrajGPT)**. It introduces a data-dependent decay mechanism that adaptively forgets irrelevant information based on clinical context. By interpreting TrajGPT as ordinary differential equations (ODEs), our approach captures continuous dynamics from sparse and irregular time-series data. Experimental results show that TrajGPT, with its time-specific inference approach, accurately predicts trajectories without requiring task-specific fine-tuning.
TrajGPT: Healthcare Time-Series Representation Learning for Trajectory Prediction
Qincheng Lu
Mike He Zhu
In many domains, such as healthcare, time-series data is irregularly sampled with varying intervals between observations. This creates chall… (see more)enges for classical time-series models that require equally spaced data. To address this, we propose a novel time-series Transformer called **Trajectory Generative Pre-trained Transformer (TrajGPT)**. It introduces a data-dependent decay mechanism that adaptively forgets irrelevant information based on clinical context. By interpreting TrajGPT as ordinary differential equations (ODEs), our approach captures continuous dynamics from sparse and irregular time-series data. Experimental results show that TrajGPT, with its time-specific inference approach, accurately predicts trajectories without requiring task-specific fine-tuning.
TrajGPT: Irregular Time-Series Representation Learning for Health Trajectory Analysis
Qincheng Lu
Mike He Zhu
Bidirectional Generative Pre-training for Improving Healthcare Time-series Representation Learning
Learning time-series representations for discriminative tasks, such as classification and regression, has been a long-standing challenge in … (see more)the healthcare domain. Current pre-training methods are limited in either unidirectional next-token prediction or randomly masked token prediction. We propose a novel architecture called Bidirectional Timely Generative Pre-trained Transformer (BiTimelyGPT), which pre-trains on biosignals and longitudinal clinical records by both next-token and previous-token prediction in alternating transformer layers. This pre-training task preserves original distribution and data shapes of the time-series. Additionally, the full-rank forward and backward attention matrices exhibit more expressive representation capabilities. Using biosignals and longitudinal clinical records, BiTimelyGPT demonstrates superior performance in predicting neurological functionality, disease diagnosis, and physiological signs. By visualizing the attention heatmap, we observe that the pre-trained BiTimelyGPT can identify discriminative segments from biosignal time-series sequences, even more so after fine-tuning on the task.
Bidirectional Generative Pre-training for Improving Time Series Representation Learning
Qincheng Lu
Mike He Zhu
Bidirectional Generative Pre-training for Improving Healthcare Time-series Representation Learning
Qincheng Lu
Mike He Zhu
TimelyGPT: Extrapolatable Transformer Pre-training for Long-term Time-Series Forecasting in Healthcare
Qincheng Lu
Hao Xu
Mike He Zhu
TimelyGPT: Extrapolatable Transformer Pre-training for Long-term Time-Series Forecasting in Healthcare
Qincheng Lu
Hao Xu
Mike He Zhu
Motivation: Large-scale pre-trained models (PTMs) such as BERT and GPT have recently achieved great success in Natural Language Processing a… (see more)nd Computer Vision domains. However, the development of PTMs on healthcare time-series data is lagging behind. This underscores the limitations of the existing transformer-based architectures, particularly their scalability to handle large-scale time series and ability to capture long-term temporal dependencies. Methods: In this study, we present Timely Generative Pre-trained Transformer (TimelyGPT). TimelyGPT employs an extrapolatable position (xPos) embedding to encode trend and periodic patterns into time-series representations. It also integrates recurrent attention and temporal convolution modules to effectively capture global-local temporal dependencies. Materials: We evaluated TimelyGPT on two large-scale healthcare time series datasets corresponding to continuous biosignals and irregularly-sampled time series, respectively: (1) the Sleep EDF dataset consisting of over 1.2 billion timesteps; (2) the longitudinal healthcare administrative database PopHR, comprising 489,000 patients randomly sampled from the Montreal population. Results: In forecasting continuous biosignals, TimelyGPT achieves accurate extrapolation up to 6,000 timesteps of body temperature during the sleep stage transition, given a short look-up window (i.e., prompt) containing only 2,000 timesteps. For irregularly-sampled time series, TimelyGPT with a proposed time-specific inference demonstrates high top recall scores in predicting future diagnoses using early diagnostic records, effectively handling irregular intervals between clinical records. Together, we envision TimelyGPT to be useful in various health domains, including long-term patient health state forecasting and patient risk trajectory prediction. Availability: The open-sourced code is available at Github.