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Zhixuan Chu

21 accepted papers

2026

DistDF: Time-series Forecasting Needs Joint-distribution Wasserstein Alignment

ICLR 2026poster

Training time-series forecast models requires aligning the conditional distribution of model forecasts with that of the label sequence. The standard direct forecast (DF) approach seeks to minimize the conditional negative log-likelihood of the label sequence, typically estimated using the mean squa…

Cited by 0SourcecodeScholar
2026

Explainable Token-level Noise Filtering for LLM Fine-tuning Datasets

ICLR 2026poster

Large Language Models (LLMs) have seen remarkable advancements, achieving state-of-the-art results in diverse applications. Fine-tuning, an important step for adapting LLMs to specific downstream tasks, typically involves further training on corresponding datasets. However, a fundamental discrepancy…

Cited by 0SourceScholar
2026

Inducing Overthink: Hierarchical Genetic Algorithm-based DoS Attack on Black-Box Reasoning Models

ICML 2026poster

Large Reasoning Models (LRMs) are increasingly integrated into systems requiring reliable multi-step inference, yet this growing dependence exposes new vulnerabilities related to computational availability. In particular, LRMs exhibit a tendency to “overthink’’—producing excessively long and redunda…

Cited by 0SourceScholar
2026

JANUS: A Lightweight Framework for Jailbreaking Text-to-Image Models via Distribution Optimization

CVPR 2026

Text-to-image (T2I) models such as Stable Diffusion and DALLE remain susceptible to generating harmful or Not-Safe-For-Work (NSFW) content under jailbreak attacks despite deployed safety filters. Existing jailbreak attacks either rely on proxy-loss optimization instead of the true end-to-end objecti

Cited by 0SourcecodeScholar
2026

Optimal Transport for Reward Modeling from Noisy Feedback

ICML 2026poster

Reward models are fundamental to Reinforcement Learning from Human Feedback (RLHF), yet real-world datasets are inevitably corrupted by noisy preference. Conventional training objectives tend to overfit these errors, while existing denoising approaches often rely on homogeneous noise assumptions tha…

Cited by 0SourceScholar
2026

Quadratic Direct Forecast for Training Multi-Step Time-Series Forecast Models

ICLR 2026poster

The design of training objective is central to training time-series forecasting models. Existing training objectives such as mean squared error mostly treat each future step as an independent, equally weighted task, which we found leading to the following two issues: (1) overlook the *label autocorr…

Cited by 0SourceScholar
2025

Heuristic-Induced Multimodal Risk Distribution Jailbreak Attack for Multimodal Large Language Models

ICCV 2025poster

With the rapid advancement of multimodal large language models (MLLMs), concerns regarding their security have increasingly captured the attention of both academia and industry. Although MLLMs are vulnerable to jailbreak attacks, designing effective jailbreak attacks poses unique challenges, especia…

2025

Mitigating Social Bias in Large Language Models: A Multi-Objective Approach Within a Multi-Agent Framework

AAAI 2025technical

Natural language processing (NLP) has seen remarkable advancements with the development of large language models (LLMs). Despite these advancements, LLMs often produce socially biased outputs. Recent studies have mainly addressed this problem by prompting LLMs to behave ethically, but this approach…

2025

Probe before You Talk: Towards Black-box Defense against Backdoor Unalignment for Large Language Models

ICLR 2025poster

Backdoor unalignment attacks against Large Language Models (LLMs) enable the stealthy compromise of safety alignment using a hidden trigger while evading normal safety auditing. These attacks pose significant threats to the applications of LLMs in the real-world Large Language Model as a Service (LL…

2025

TimeMixer++: A General Time Series Pattern Machine for Universal Predictive Analysis

ICLR 2025oral

Time series analysis plays a critical role in numerous applications, supporting tasks such as forecasting, classification, anomaly detection, and imputation. In this work, we present the time series pattern machine (TSPM), a model designed to excel in a broad range of time series tasks through power…

2025

Understanding and Mitigating Overrefusal in LLMs from an Unveiling Perspective of Safety Decision Boundary

EMNLP 2025

Large language models (LLMs) have demonstrated remarkable capabilities across a wide range of tasks, yet they often refuse to answer legitimate queries—a phenomenon known as overrefusal. Overrefusal typically stems from over-conservative safety alignment, causing models to treat many reasonable prom

2024

EasyTPP: Towards Open Benchmarking Temporal Point Processes

ICLR 2024poster

Continuous-time event sequences play a vital role in real-world domains such as healthcare, finance, online shopping, social networks, and so on. To model such data, temporal point processes (TPPs) have emerged as the most natural and competitive models, making a significant impact in both academic…

2024

Enhancing Event Sequence Modeling with Contrastive Relational Inference

ICASSP 2024accepted

Neural temporal point processes(TPPs) have shown promise for modeling continuous-time event sequences. However, capturing the interactions between events is challenging yet critical for performing inference tasks like forecasting on event sequence data. Existing TPP models have focused on parameteri…

Cited by 0SourceScholar
2024

LLMRG: Improving Recommendations through Large Language Model Reasoning Graphs

AAAI 2024technical

Recommendation systems aim to provide users with relevant suggestions, but often lack interpretability and fail to capture higher-level semantic relationships between user behaviors and profiles. In this paper, we propose a novel approach that leverages large language models (LLMs) to construct pers…

Cited by 16SourcePDFScholar
2024

Self-Para-Consistency: Improving Reasoning Tasks at Low Cost for Large Language Models

ACL 2024findings

Recently, the self-consistency decoding strategy has shown the ability to improve performance for complex reasoning tasks with large language models (LLMs). However, the costs may be high because the sampling process of the strategy generates some low-probability text, resulting in low-quality reaso…

Cited by 5SourcePDFScholar
2024

Task-Driven Causal Feature Distillation: Towards Trustworthy Risk Prediction

AAAI 2024technical

Since artificial intelligence has seen tremendous recent successes in many areas, it has sparked great interest in its potential for trustworthy and interpretable risk prediction. However, most models lack causal reasoning and struggle with class imbalance, leading to poor precision and recall. To a…

Cited by 11SourcePDFScholar
2024

Time-LLM: Time Series Forecasting by Reprogramming Large Language Models

ICLR 2024poster

Time series forecasting holds significant importance in many real-world dynamic systems and has been extensively studied. Unlike natural language process (NLP) and computer vision (CV), where a single large model can tackle multiple tasks, models for time series forecasting are often specialized, ne…

2023

Prompt-augmented Temporal Point Process for Streaming Event Sequence

NeurIPS 2023poster

Neural Temporal Point Processes (TPPs) are the prevalent paradigm for modeling continuous-time event sequences, such as user activities on the web and financial transactions. In real world applications, the event data typically comes in a streaming manner, where the distribution of the patterns may…

Cited by 26SourcePDFScholar
2023

pTSE: A Multi-model Ensemble Method for Probabilistic Time Series Forecasting

IJCAI 2023poster

Various probabilistic time series forecasting models have sprung up and shown remarkably good performance. However, the choice of model highly relies on the characteristics of the input time series and the fixed distribution that model is based on. Due to the fact that the probability distributions…

Cited by 10SourcePDFScholar
2022

Incorporating Causal Analysis into Diversified and Logical Response Generation

COLING 2022main

Although the Conditional Variational Auto-Encoder (CVAE) model can generate more diversified responses than the traditional Seq2Seq model, the responses often have low relevance with the input words or are illogical with the question. A causal analysis is carried out to study the reasons behind, and…

Cited by 7SourcePDFScholar