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Mei Chen

21 accepted papers

2026

Beta Distribution Learning for Reliable Roadway Crash Risk Assessment

AAAI 2026technical

Roadway traffic accidents represent a global health crisis, responsible for over a million deaths annually and costing many countries up to 3% of their GDP. Traditional traffic safety studies often examine risk factors in isolation, overlooking the spatial complexity and contextual interactions inhe

Cited by 0SourcePDFScholar
2026

PISCES: Annotation-free Text-to-Video Post-Training via Optimal Transport-Aligned Rewards

ICML 2026poster

Text-to-video (T2V) generation aims to synthesize videos with high visual quality and temporal consistency that are semantically aligned with input text. Reward-based post-training has emerged as a promising direction to improve the quality and semantic alignment of generated videos. However, recent…

Cited by 0SourceScholar
2026

Scenes as Tokens: Multi-Scale Normal Distributions Transform Tokenizer for General 3D Vision-Language Understanding

CVPR 2026

Recent advances in 3D vision-language models (VLMs) highlight a strong potential for 3D scene understanding and reasoning.However, effectively tokenizing 3D scenes into holistic scene tokens, and leveraging these tokens across diverse 3D understanding tasks, remain highly challenging. We present NDT

Cited by 0SourcecodeScholar
2026

Tracking-Guided 4D Generation: Foundation-Tracker Motion Priors for 3D Model Animation

CVPR 2026

Generating dynamic 4D objects from sparse inputs is difficult because it demands joint preservation of appearance and motion coherence across views and time while suppressing artifacts and temporal drift. We hypothesize that the view discrepancy arises from supervision limited to pixel- or latent-sp

Cited by 0SourceScholar
2025

DeCafNet: Delegate and Conquer for Efficient Temporal Grounding in Long Videos

CVPR 2025poster

Long Video Temporal Grounding (LVTG) aims at identifying specific moments within lengthy videos based on user-provided text queries for effective content retrieval. The approach taken by existing methods of dividing video into clips and processing each clip via a full-scale expert encoder is challen…

2025

Defense against Prompt Injection Attacks via Mixture of Encodings

NAACL 2025short

Large Language Models (LLMs) have emerged as a dominant approach for a wide range of NLP tasks, with their access to external information further enhancing their capabilities. However, this introduces new vulnerabilities, known as prompt injection attacks, where external content embeds malicious ins…

2025

Hummingbird: High Fidelity Image Generation via Multimodal Context Alignment

ICLR 2025poster

While diffusion models are powerful in generating high-quality, diverse synthetic data for object-centric tasks, existing methods struggle with scene-aware tasks such as Visual Question Answering (VQA) and Human-Object Interaction (HOI) Reasoning, where it is critical to preserve scene attributes in…

2025

SplatFlow: Self-Supervised Dynamic Gaussian Splatting in Neural Motion Flow Field for Autonomous Driving

CVPR 2025highlight

Most existing Dynamic Gaussian Splatting methods for complex dynamic urban scenarios rely on accurate object-level supervision from expensive manual labeling, limiting their scalability in real-world applications. In this paper, we introduce SplatFlow, a Self-Supervised Dynamic Gaussian Splatting wi…

Cited by 0SourcePDFScholar
2024

Revisiting Adaptive Cellular Recognition Under Domain Shifts: A Contextual Correspondence View

ECCV 2024oral

"Cellular nuclei recognition serves as a fundamental and essential step in the workflow of digital pathology. However, with disparate source organs and staining procedures among histology image clusters, the scanned tiles inherently conform to a non-uniform data distribution, which induces deteriora…

2024

Seeing Unseen: Discover Novel Biomedical Concepts via Geometry-Constrained Probabilistic Modeling

CVPR 2024poster

Machine learning holds tremendous promise for transforming the fundamental practice of scientific discovery by virtue of its data-driven nature. With the ever-increasing stream of research data collection it would be appealing to autonomously explore patterns and insights from observational data for…

Cited by 6SourcePDFScholar
2023

PivoTAL: Prior-Driven Supervision for Weakly-Supervised Temporal Action Localization

CVPR 2023poster

Weakly-supervised Temporal Action Localization (WTAL) attempts to localize the actions in untrimmed videos using only video-level supervision. Most recent works approach WTAL from a localization-by-classification perspective where these methods try to classify each video frame followed by a manually…

Cited by 42SourcePDFScholar
2023

ProTeGe: Untrimmed Pretraining for Video Temporal Grounding by Video Temporal Grounding

CVPR 2023poster

Video temporal grounding (VTG) is the task of localizing a given natural language text query in an arbitrarily long untrimmed video. While the task involves untrimmed videos, all existing VTG methods leverage features from video backbones pretrained on trimmed videos. This is largely due to the lack…

Cited by 15SourcePDFScholar
2023

Rule By Example: Harnessing Logical Rules for Explainable Hate Speech Detection

ACL 2023long

Classic approaches to content moderation typically apply a rule-based heuristic approach to flag content. While rules are easily customizable and intuitive for humans to interpret, they are inherently fragile and lack the flexibility or robustness needed to moderate the vast amount of undesirable co…

2023

Taxonomy Adaptive Cross-Domain Adaptation in Medical Imaging via Optimization Trajectory Distillation

ICCV 2023poster

The success of automated medical image analysis depends on large-scale and expert-annotated training sets. Unsupervised domain adaptation (UDA) has been raised as a promising approach to alleviate the burden of labeled data collection. However, they generally operate under the closed-set adaptation…

Cited by 15PDFcodeScholar
2022

BATMAN: Bilateral Attention Transformer in Motion-Appearance Neighboring Space for Video Object Segmentation

ECCV 2022poster

"Video Object Segmentation (VOS) is fundamental to video understanding. Transformer-based methods show significant performance improvement on semi-supervised VOS. However, existing work faces challenges segmenting visually similar objects in close proximity of each other. In this paper, we propose a…

Cited by 31SourcePDFScholar
2022

GateHUB: Gated History Unit With Background Suppression for Online Action Detection

CVPR 2022poster

Online action detection is the task of predicting the action as soon as it happens in a streaming video. A major challenge is that the model does not have access to the future and has to solely rely on the history, i.e., the frames observed so far, to make predictions. It is therefore important to a…

Cited by 55PDFcodeScholar
2021

Revisiting Dynamic Convolution via Matrix Decomposition

ICLR 2021poster

Recent research in dynamic convolution shows substantial performance boost for efficient CNNs, due to the adaptive aggregation of K static convolution kernels. It has two limitations: (a) it increases the number of convolutional weights by K-times, and (b) the joint optimization of dynamic attention…

2021

Stronger NAS with Weaker Predictors

NeurIPS 2021poster

Neural Architecture Search (NAS) often trains and evaluates a large number of architectures. Recent predictor-based NAS approaches attempt to alleviate such heavy computation costs with two key steps: sampling some architecture-performance pairs and fitting a proxy accuracy predictor. Given limited…

2021

Unsupervised Few-Shot Action Recognition via Action-Appearance Aligned Meta-Adaptation

ICCV 2021poster

We present MetaUVFS as the first Unsupervised Meta-learning algorithm for Video Few-Shot action recognition. MetaUVFS leverages over 550K unlabeled videos to train a two-stream 2D and 3D CNN architecture via contrastive learning to capture the appearance-specific spatial and action-specific spatio-t…

Cited by 27PDFScholar
2020

HyperSTAR: Task-Aware Hyperparameters for Deep Networks

CVPR 2020oral

While deep neural networks excel in solving visual recognition tasks, they require significant effort to find hyperparameters that make them work optimally. Hyperparameter Optimization (HPO) approaches have automated the process of finding good hyperparameters but they do not adapt to a given task (…

Cited by 36PDFScholar
2020

Unsupervised Instance Segmentation in Microscopy Images via Panoptic Domain Adaptation and Task Re-Weighting

CVPR 2020poster

Unsupervised domain adaptation (UDA) for nuclei instance segmentation is important for digital pathology, as it alleviates the burden of labor-intensive annotation and domain shift across datasets. In this work, we propose a Cycle Consistency Panoptic Domain Adaptive Mask R-CNN (CyC-PDAM) architectu…

Cited by 98PDFcodeScholar