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Zhen Fang

38 accepted papers

2026

A Close Look at Negative Label Guided Out-of-distribution Detection in Pre-trained Vision-Language Models

ICML 2026poster

Advances in pre-trained vision-language models have enabled zero-shot out-of-distribution (OOD) detection using only in-distribution (ID) labels. Recent methods in this direction expand the label space with negative labels to enhance the discrimination between ID and OOD inputs. Despite their promis…

Cited by 0SourceScholar
2026

Beyond In-Domain Detection: SpikeScore for Cross-Domain Hallucination Detection

ICLR 2026poster

Hallucination detection is critical for deploying large language models (LLMs) in real-world applications. Existing hallucination detection methods achieve strong performance when the training and test data come from the same domain, but they suffer from poor cross-domain generalization. In this pap…

Cited by 0SourcecodeScholar
2026

Delving into Spectral Clustering with Vision-Language Representations

ICLR 2026poster

Spectral clustering is known as a powerful technique in unsupervised data analysis. The vast majority of approaches to spectral clustering are driven by a single modality, leaving the rich information in multi-modal representations untapped. Inspired by the recent success of vision-language pre-tr…

Cited by 0SourceScholar
2026

Explainable LLM Unlearning through Reasoning

ICLR 2026poster

LLM unlearning is essential for mitigating safety, copyright, and privacy concerns in pre-trained Large Language Models (LLMs). Compared to preference alignment, it offers a more explicit way by removing undesirable knowledge characterized by specific unlearning datasets. In previous works, Gradien…

Cited by 0SourcecodeScholar
2026

How Do Transformers Learn to Associate Tokens: Gradient Leading Terms Bring Mechanistic Interpretability

ICLR 2026oral

Semantic associations such as the link between "bird" and "flew" are foundational for language modeling as they enable models to go beyond memorization and instead generalize and generate coherent text. Understanding how these associations are learned and represented in language models is essential…

Cited by 0SourceScholar
2026

NSC-SL: A Bandwidth-Aware Neural Subspace Compression for Communication-Efficient Split Learning

ICASSP 2026poster

The expanding scale of neural networks poses a major challenge for distributed machine learning, particularly under limited communication resources. While split learning (SL) alleviates client computational burden by distributing model layers between clients and server, it incurs substantial communi…

Cited by 0SourcePDFScholar
2026

Respecting Modality Gap in Post-hoc Out-of-distribution Detection with Pre-trained Vision-Language Models

ICML 2026poster

Out-of-distribution (OOD) detection has emerged as a popular technique to enhance the reliability of machine learning models by identifying unexpected inputs from unknown classes. Recent progress in pre-trained vision–language models (VLMs) has enabled zero-shot OOD detection without access to in-di…

Cited by 0SourceScholar
2025

An Information-theoretical Framework for Understanding Out-of-distribution Detection with Pretrained Vision-Language Models

NeurIPS 2025poster

Out-of-distribution (OOD) detection, recognized for its ability to identify samples of unknown classes, provides solid advantages in ensuring the reliability of machine learning models. Among existing OOD detection methods, pre-trained vision-language models have emerged as powerful post-hoc OOD de…

Cited by 0SourceScholar
2025

CRITICTOOL: Evaluating Self-Critique Capabilities of Large Language Models in Tool-Calling Error Scenarios

EMNLP 2025

The ability of large language models (LLMs) to utilize external tools has enabled them to tackle an increasingly diverse range of tasks. However, as the tasks become more complex and long-horizon, the intricate tool utilization process may trigger various unexpected errors. Therefore, how to effecti

2025

Deep Kernel Relative Test for Machine-generated Text Detection

ICLR 2025poster

Recent studies demonstrate that two-sample test can effectively detect machine-generated texts (MGTs) with excellent adaptation ability to texts generated by newer LLMs. However, two-sample test-based detection relies on the assumption that human-written texts (HWTs) must follow the distribution of…

2025

Learning Robust Spectral Dynamics for Temporal Domain Generalization

NeurIPS 2025poster

Modern machine learning models struggle to maintain performance in dynamic environments where temporal distribution shifts, \textit{i.e., concept drift}, are prevalent. Temporal Domain Generalization (TDG) seeks to enable model generalization across evolving domains, yet existing approaches typicall…

Cited by 0SourceScholar
2025

NLPrompt: Noise-Label Prompt Learning for Vision-Language Models

CVPR 2025highlight

The emergence of vision-language foundation models, such as CLIP, has revolutionized image-text representation, enabling a broad range of applications via prompt learning. Despite its promise, real-world datasets often contain noisy labels that can degrade prompt learning performance. In this paper,…

2025

On the Provable Importance of Gradients for Autonomous Language-Assisted Image Clustering

ICCV 2025poster

This paper investigates the recently emerged problem of Language-assisted Image Clustering (LaIC), where textual semantics are leveraged to improve the discriminability of visual representations to facilitate image clustering. Due to the unavailability of true class names, one of core challenges of…

Cited by 0SourcePDFScholar
2025

Provable Ordering and Continuity in Vision-Language Pretraining for Generalizable Embodied Agents

NeurIPS 2025poster

Pre-training vision-language representations on human action videos has emerged as a promising approach to reduce reliance on large-scale expert demonstrations for training embodied agents. However, prior methods often employ time con- trastive learning based on goal-reaching heuristics, progressive…

Cited by 0SourcecodeScholar
2025

Release the Powers of Prompt Tuning: Cross-Modality Prompt Transfer

ICLR 2025poster

Prompt Tuning adapts frozen models to new tasks by prepending a few learnable embeddings to the input. However, it struggles with tasks that suffer from data scarcity. To address this, we explore Cross-Modality Prompt Transfer, leveraging prompts pretrained on a data-rich modality to improve perform…

Cited by 0SourcePDFScholar
2025

Understanding Multimodal LLMs Under Distribution Shifts: An Information-Theoretic Approach

ICML 2025poster

Multimodal large language models (MLLMs) have shown promising capabilities but struggle under distribution shifts, where evaluation data differ from instruction tuning distributions. Although previous works have provided empirical evaluations, we argue that establishing a formal framework that can c…

Cited by 2SourcePDFScholar
2024

ConjNorm: Tractable Density Estimation for Out-of-Distribution Detection

ICLR 2024poster

Post-hoc out-of-distribution (OOD) detection has garnered intensive attention in reliable machine learning. Many efforts have been dedicated to deriving score functions based on logits, distances, or rigorous data distribution assumptions to identify low-scoring OOD samples. Nevertheless, these esti…

Cited by 11SourcePDFScholar
2024

How Does Unlabeled Data Provably Help Out-of-Distribution Detection?

ICLR 2024poster

Using unlabeled data to regularize the machine learning models has demonstrated promise for improving safety and reliability in detecting out-of-distribution (OOD) data. Harnessing the power of unlabeled in-the-wild data is non-trivial due to the heterogeneity of both in-distribution (ID) and OOD da…

2024

Learning to Shape In-distribution Feature Space for Out-of-distribution Detection

NeurIPS 2024poster

Out-of-distribution (OOD) detection is critical for deploying machine learning models in the open world. To design scoring functions that discern OOD data from the in-distribution (ID) cases from a pre-trained discriminative model, existing methods tend to make rigorous distributional assumptions ei…

Cited by 2SourcePDFScholar
2024

Negative Label Guided OOD Detection with Pretrained Vision-Language Models

ICLR 2024spotlight

Out-of-distribution (OOD) detection aims at identifying samples from unknown classes, playing a crucial role in trustworthy models against errors on unexpected inputs. Extensive research has been dedicated to exploring OOD detection in the vision modality. {Vision-language models (VLMs) can lever…

2024

NoiseDiffusion: Correcting Noise for Image Interpolation with Diffusion Models beyond Spherical Linear Interpolation

ICLR 2024spotlight

Image interpolation based on diffusion models is promising in creating fresh and interesting images. Advanced interpolation methods mainly focus on spherical linear interpolation, where images are encoded into the noise space and then interpolated for denoising to images. However, existing methods…

2024

Out-of-Distribution Detection with Negative Prompts

ICLR 2024poster

Out-of-distribution (OOD) detection is indispensable for open-world machine learning models. Inspired by recent success in large pre-trained language-vision models, e.g., CLIP, advanced works have achieved impressive OOD detection results by matching the *similarity* between image features and featu…

Cited by 22SourcePDFScholar
2023

Continual Named Entity Recognition without Catastrophic Forgetting

EMNLP 2023long main

Continual Named Entity Recognition (CNER) is a burgeoning area, which involves updating an existing model by incorporating new entity types sequentially. Nevertheless, continual learning approaches are often severely afflicted by catastrophic forgetting. This issue is intensified in CNER due to the…

Cited by 0SourcecodeScholar
2023

Detecting Out-of-distribution Data through In-distribution Class Prior

ICML 2023poster

Given a pre-trained in-distribution (ID) model, the inference-time out-of-distribution (OOD) detection aims to recognize OOD data during the inference stage. However, some representative methods share an unproven assumption that the probability that OOD data belong to every ID class should be the sa…

2023

Invariant Learning via Probability of Sufficient and Necessary Causes

NeurIPS 2023spotlight

Out-of-distribution (OOD) generalization is indispensable for learning models in the wild, where testing distribution typically unknown and different from the training. Recent methods derived from causality have shown great potential in achieving OOD generalization. However, existing methods mainly…

2023

KECOR: Kernel Coding Rate Maximization for Active 3D Object Detection

ICCV 2023poster

Achieving a reliable LiDAR-based object detector in autonomous driving is paramount, but its success hinges on obtaining large amounts of precise 3D annotations. Active learning (AL) seeks to mitigate the annotation burden through algorithms that use fewer labels and can attain performance comparabl…

Cited by 19PDFScholar
2023

Learning to Augment Distributions for Out-of-distribution Detection

NeurIPS 2023poster

Open-world classification systems should discern out-of-distribution (OOD) data whose labels deviate from those of in-distribution (ID) cases, motivating recent studies in OOD detection. Advanced works, despite their promising progress, may still fail in the open world, owing to the lacking knowledg…

2023

Moderately Distributional Exploration for Domain Generalization

ICML 2023poster

Domain generalization (DG) aims to tackle the distribution shift between training domains and unknown target domains. Generating new domains is one of the most effective approaches, yet its performance gain depends on the distribution discrepancy between the generated and target domains. Distributio…

2023

Out-of-distribution Detection Learning with Unreliable Out-of-distribution Sources

NeurIPS 2023poster

Out-of-distribution (OOD) detection discerns OOD data where the predictor cannot make valid predictions as in-distribution (ID) data, thereby increasing the reliability of open-world classification. However, it is typically hard to collect real out-of-distribution (OOD) data for training a predictor…

2023

SODA: Robust Training of Test-Time Data Adaptors

NeurIPS 2023poster

Adapting models deployed to test distributions can mitigate the performance degradation caused by distribution shifts. However, privacy concerns may render model parameters inaccessible. One promising approach involves utilizing zeroth-order optimization (ZOO) to train a data adaptor to adapt the te…

2021

Confident Anchor-Induced Multi-Source Free Domain Adaptation

NeurIPS 2021poster

Unsupervised domain adaptation has attracted appealing academic attentions by transferring knowledge from labeled source domain to unlabeled target domain. However, most existing methods assume the source data are drawn from a single domain, which cannot be successfully applied to explore complement…

2021

How Does the Combined Risk Affect the Performance of Unsupervised Domain Adaptation Approaches?

AAAI 2021technical

Unsupervised domain adaptation (UDA) aims to train a target classifier with labeled samples from the source domain and unlabeled samples from the target domain. Classical UDA learning bounds show that target risk is upper bounded by three terms: source risk, distribution discrepancy, and combined ri…

2020

Clarinet: A One-step Approach Towards Budget-friendly Unsupervised Domain Adaptation

IJCAI 2020poster

In unsupervised domain adaptation (UDA), classifiers for the target domain are trained with massive true-label data from the source domain and unlabeled data from the target domain. However, it may be difficult to collect fully-true-label data in a source domain given limited budget. To mitigate thi…