
Jiaqi Gu
Postdoctoral Scholar, Neurology and Neurological Sciences
Bio
I am a postdoctoral scholar in Department of Neurology & Neurological Sciences, Stanford University and under supervision of Dr. Zihuai He. Before that, I obtained my PhD degree in statistics under supervision of Prof. Philip L.H. Yu and Prof. Guosheng Yin in University of Hong Kong and my bachelor degrees in statistics from Renmin University of China.
My researches concentrate on preference learning, network data modeling, quantitative analysis of survival and public health data, high-dimensional statistical inference with geometric information and statistical genetics.
Honors & Awards
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Excellent Research Award, Department of Statistics and Actuarial Science, University of Hong Kong (2022)
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Excellent Research Award, Department of Statistics and Actuarial Science, University of Hong Kong (2021)
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Excellent Teaching Assistant Award, Department of Statistics and Actuarial Science, University of Hong Kong (2021)
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Honorable Mention, Interdisciplinary Contest in Modeling (2017)
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Runner-up, Beijing-Hong Kong Data Modeling Competition (2017)
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First Prize, Contemporary Undergraduate Mathematical Contest in Modeling (Beijing) (2016)
Professional Education
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Ph.D., University of Hong Kong, Statistics (2022)
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B.S., Renmin University of China, Statistics (2018)
All Publications
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Omnibus test for restricted mean survival time based on influence function.
Statistical methods in medical research
2023: 9622802231158735
Abstract
The restricted mean survival time (RMST), which evaluates the expected survival time up to a pre-specified time point τ, has been widely used to summarize the survival distribution due to its robustness and straightforward interpretation. In comparative studies with time-to-event data, the RMST-based test has been utilized as an alternative to the classic log-rank test because the power of the log-rank test deteriorates when the proportional hazards assumption is violated. To overcome the challenge of selecting an appropriate time point τ, we develop an RMST-based omnibus Wald test to detect the survival difference between two groups throughout the study follow-up period. Treating a vector of RMSTs at multiple quantile-based time points as a statistical functional, we construct a Wald χ2 test statistic and derive its asymptotic distribution using the influence function. We further propose a new procedure based on the influence function to estimate the asymptotic covariance matrix in contrast to the usual bootstrap method. Simulations under different scenarios validate the size of our RMST-based omnibus test and demonstrate its advantage over the existing tests in power, especially when the true survival functions cross within the study follow-up period. For illustration, the proposed test is applied to two real datasets, which demonstrate its power and applicability in various situations.
View details for DOI 10.1177/09622802231158735
View details for PubMedID 37015346
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ANALYSIS OF PREFERENCES IN SOCIAL NETWORKS
ANNALS OF APPLIED STATISTICS
2023; 17 (1): 89-107
View details for DOI 10.1214/22-AOAS1617
View details for Web of Science ID 000929003900005
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Bayesian Log-Rank Test
AMERICAN STATISTICIAN
2023
View details for DOI 10.1080/00031305.2022.2161637
View details for Web of Science ID 000908150700001
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Bayesian SIR model with change points with application to the Omicron wave in Singapore
SCIENTIFIC REPORTS
2022; 12 (1): 20864
Abstract
The Omicron variant has led to a new wave of the COVID-19 pandemic worldwide, with unprecedented numbers of daily confirmed new cases in many countries and areas. To analyze the impact of society or policy changes on the development of the Omicron wave, the stochastic susceptible-infected-removed (SIR) model with change points is proposed to accommodate the situations where the transmission rate and the removal rate may vary significantly at change points. Bayesian inference based on a Markov chain Monte Carlo algorithm is developed to estimate both the locations of change points as well as the transmission rate and removal rate within each stage. Experiments on simulated data reveal the effectiveness of the proposed method, and several stages are detected in analyzing the Omicron wave data in Singapore.
View details for DOI 10.1038/s41598-022-25473-y
View details for Web of Science ID 000932261400072
View details for PubMedID 36460721
View details for PubMedCentralID PMC9718478
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Triangular Concordance Learning of Networks
JOURNAL OF COMPUTATIONAL AND GRAPHICAL STATISTICS
2022
View details for DOI 10.1080/10618600.2022.2099405
View details for Web of Science ID 000853487100001
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Sparse concordance-based ordinal classification
SCANDINAVIAN JOURNAL OF STATISTICS
2022
View details for DOI 10.1111/sjos.12606
View details for Web of Science ID 000846860600001
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Joint latent space models for ranking data and social network
STATISTICS AND COMPUTING
2022; 32 (3)
View details for DOI 10.1007/s11222-022-10106-1
View details for Web of Science ID 000810665300001
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Reconstructing the Kaplan-Meier Estimator as an M-estimator
AMERICAN STATISTICIAN
2022; 76 (1): 37-43
View details for DOI 10.1080/00031305.2021.1947376
View details for Web of Science ID 000678954700001
- Crystallization Learning with the Delaunay Triangulation The 38th International Conference on Machine Learning 2021: 3854-3863
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Analysis of ranking data
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL STATISTICS
2019; 11 (6)
View details for DOI 10.1002/wics.1483
View details for Web of Science ID 000489576600004
- Fast Algorithm for Generalized Multinomial Models with Ranking Data The 36th International Conference on Machine Learning 2019: 2445- 2453