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From the 1 of 7 linked papers with an AI index.

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7 papers

stat.ME2026

Generative Synthetic Data for Causal Inference: Pitfalls, Remedies, and Opportunities

Yichen Xu

The paper examines how fully generative synthetic data models can preserve predictive performance but distort causal estimates, and proposes a hybrid synthetic-data approach that s…

stat.ME2026

Adaptive Targeted Maximum Likelihood Estimation of the Mean Potential Outcome under a Treatment Rule

Yichen Xu, Mark J. van der Laan

Estimating the mean counterfactual outcome under a treatment rule is a central problem in causal inference and policy evaluation. Standard estimators, including inverse probability…

stat.ME2026

Investigating Targeting Strategies and Truncation in TMLE for the Average Treatment Effect under Practical Positivity Violations

Yichen Xu, Susan Gruber, Mark J. van der Laan

Estimating average treatment effects from observational data is challenging under practical violations of the positivity assumption. Targeted Maximum Likelihood Estimators (TMLEs)…

cs.LG2026

Evolution of Optimization Methods: Algorithms, Scenarios, and Evaluations

Tong Zhang, Jiangning Zhang, Zhucun Xue +9

Balancing convergence speed, generalization capability, and computational efficiency remains a core challenge in deep learning optimization. First-order gradient descent methods, e…

cs.LG2026

Residual Feature Integration is Sufficient to Prevent Negative Transfer

Yichen Xu, Ryumei Nakada, Linjun Zhang +1

Transfer learning has become a central paradigm in modern machine learning, yet it suffers from the long-standing problem of negative transfer, where leveraging source representati…

cs.LG2026

Understanding and Guiding Layer Placement in Parameter-Efficient Fine-Tuning of Large Language Models

Yichen Xu, Yuyang Liang, Shan Dai +3

As large language models (LLMs) continue to grow, the cost of full-parameter fine-tuning has made parameter-efficient fine-tuning (PEFT) the default strategy for downstream adaptat…