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Xiyuan Zhang

12 accepted papers

2026

MRACL: Multi-Reward Space Guided Adaptive Curriculum Reinforcement Learning for LLMs

AAAI 2026technical

Reinforcement learning (RL) has recently become a powerful yet resource-intensive approach for post-training large language models (LLMs). Incorporating curriculum learning (CL) into RL has been shown to significantly improve training efficiency, particularly in reasoning tasks. However, existing CL

Cited by 0SourcePDFScholar
2026

Understanding Transformers for Time Series: Rank Structure, Flow-of-ranks, and Compressibility

ICLR 2026poster

Transformers are widely used across data modalities, and yet the principles distilled from text models often transfer imperfectly. In this paper, we analyze Transformers through the lens of rank structure. Our focus is on the time series setting, where the structural properties of the data remarkabl…

Cited by 0SourcecodeScholar
2026

Understanding the Implicit Biases of Design Choices for Time Series Foundation Models

ICLR 2026poster

Time series foundation models (TSFMs) are a potential class of powerful, general-purpose tools for forecasting and related temporal tasks, but their behavior is strongly shaped by subtle inductive biases in their design. Rather than developing a new model and claiming that it is better than existin…

Cited by 0SourceScholar
2025

Adaptive Noise Rejection Strategy for Cooperative Motion Control of Dual-Arm Robots

RA-L 2025

Dual-arm robots possess exceptional collaborative capabilities and versatility, demonstrating broad application prospects across various fields. As a significant research area for dual-arm robots, the requirements for coordinated motion control are gradually increasing. In practical applications, ro

Cited by 3SourceScholar
2025

Enhancing Foundation Models for Time Series Forecasting via Wavelet-based Tokenization

ICML 2025poster

How to best develop foundational models for time series forecasting remains an important open question. Tokenization is a crucial consideration in this effort: what is an effective discrete vocabulary for a real-valued sequential input? To address this question, we develop WaveToken, a wavelet-based…

Cited by 2SourcePDFScholar
2025

MLZero: A Multi-Agent System for End-to-end Machine Learning Automation

NeurIPS 2025poster

Existing AutoML systems have advanced the automation of machine learning (ML); however, they still require substantial manual configuration and expert input, particularly when handling multimodal data. We introduce MLZero, a novel multi-agent framework powered by Large Language Models (LLMs) that en…

Cited by 0SourcecodeScholar
2025

Mitra: Mixed Synthetic Priors for Enhancing Tabular Foundation Models

NeurIPS 2025poster

Since the seminal work of TabPFN, research on tabular foundation models (TFMs) based on in-context learning (ICL) has challenged long-standing paradigms in machine learning. Without seeing any real-world data, models pretrained on purely synthetic datasets generalize remarkably well across diverse d…

Cited by 0SourceScholar
2025

ZeroHAR: Sensor Context Augments Zero-Shot Wearable Action Recognition

AAAI 2025technical

Wearable Human Action Recognition (wHAR) uses motion sensor data to identify human movements, which is essential for mobile and wearable devices. However, traditional wHAR systems are only trained on a limited set of activities. Hence, they fail to generalize to diverse human motions, prompting Zero…

Cited by 0SourcePDFScholar
2024

Large Language Models for Time Series: A Survey

IJCAI 2024poster

Large Language Models (LLMs) have seen significant use in domains such as natural language processing and computer vision. Going beyond text, image and graphics, LLMs present a significant potential for analysis of time series data, benefiting domains such as climate, IoT, healthcare, traffic, audio…

2024

UniMTS: Unified Pre-training for Motion Time Series

NeurIPS 2024poster

Motion time series collected from low-power, always-on mobile and wearable devices such as smartphones and smartwatches offer significant insights into human behavioral patterns, with wide applications in healthcare, automation, IoT, and AR/XR. However, given security and privacy concerns, building…

2023

PrimeNet: Pre-training for Irregular Multivariate Time Series

AAAI 2023technical

Real-world applications often involve irregular time series, for which the time intervals between successive observations are non-uniform. Irregularity across multiple features in a multi-variate time series further results in a different subset of features at any given time (i.e., asynchronicity).…

2023

Towards Diverse and Coherent Augmentation for Time-Series Forecasting

ICASSP 2023accepted

Time-series data augmentation mitigates the issue of insufficient training data for deep learning models. Yet, existing augmentation methods are mainly designed for classification, where class labels can be preserved even if augmentation alters the temporal dynamics. We note that augmentation design…

Cited by 0SourceScholar