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Chenxi Liu

40 accepted papers

2026

Anatomical Region-Guided Contrastive Decoding: A Plug-and-Play Strategy for Mitigating Hallucinations in Medical VLMs

AAAI 2026technical

Medical Vision-Language Models (MedVLMs) show immense promise in clinical applicability. However, their reliability is hindered by hallucinations, where models often fail to derive answers from visual evidence, instead relying on learned textual priors. Existing mitigation strategies for MedVLMs hav

Cited by 0SourcePDFScholar
2026

CausalGame: Benchmarking Causal Thinking of LLM Agents in Games

ICML 2026oral

Recently, it has received growing attention in building AI Scientist agents with Large Language Models (LLMs). Since scientific discovery fundamentally relies on uncovering causal relationships from observations, the capability of causal thinking that distinguish causation from correlation and hidde…

Cited by 0SourceScholar
2026

From Dialogue to Destination: Geography-Aware Large Language Models with Multimodal Fusion for Conversational Recommendation

AAAI 2026technical

Conversational Recommender Systems (CRS) aim to provide personalized recommendations by interacting with users through natural language dialogue. However, in scenarios requiring deep geospatial awareness, existing methods, including those based on Large Language Models (LLMs), still face significant

Cited by 0SourcePDFScholar
2026

Invariant Representation Learning for Source-Free Time Series Forecasting with LLM-Centric Proxy Denoising

ICML 2026poster

Effective time series forecasting enables various real-world applications, benefiting from the proliferation of mobile devices. However, the volume of time series data may vary significantly across domains due to low sampling rates and data regulations. To maximally create value from sparse data, th…

Cited by 0SourceScholar
2026

Multi-Crit: Benchmarking Multimodal Judges on Pluralistic Criteria-Following

CVPR 2026

Large multimodal models (LMMs) are increasingly adopted as judges in multimodal evaluation systems due to their strong instruction following and consistency with human preferences. However, their ability to follow diverse, fine-grained evaluation criteria remains underexplored. We develop Multi-Crit

Cited by 0SourcecodeScholar
2026

Multi-View Ensemble for Time Series Anomaly Detection via Coupling Flows

IJCAI 2026

Time series anomaly detection faces a critical challenge that different anomaly types require different detection mechanisms, yet single methods are inherently limited by their design biases. We propose FlowFuse, a multi-view ensemble framework with coupling flow-based score fusion for time series a

Cited by 0Scholar
2026

On the Thinking-Language Modeling Gap in Large Language Models

ICLR 2026poster

Large Language Models (LLMs) demonstrate remarkable capabilities in solving complicated reasoning tasks by imitating the human thinking process from human languages. However, even the most capable LLMs can still fail in tasks that are simple for humans. To understand the gap, we construct structural…

Cited by 0SourcecodeScholar
2026

SemLayer: Semantic-aware Generative Segmentation and Layer Construction for Abstract Icons

CVPR 2026

Graphic icons are a cornerstone of modern design workflows, yet they are often distributed as flattened single-path or compound-path graphics, where the original semantic layering is lost. This absence of semantic decomposition hinders downstream tasks such as editing, restyling, and animation. We f

Cited by 0SourcecodeScholar
2026

V2P-Bench: Evaluating Video-Language Understanding with Visual Prompts for Better Human-Model Interaction

ICLR 2026poster

Large Vision-Language Models (LVLMs) have made significant strides in the field of video understanding in recent times. Nevertheless, existing video benchmarks predominantly rely on text prompts for evaluation, which often require complex referential language and diminish both the accuracy and effic…

Cited by 0SourcecodeScholar
2025

A Watermark for Order-Agnostic Language Models

ICLR 2025poster

Statistical watermarking techniques are well-established for sequentially decoded language models (LMs). However, these techniques cannot be directly applied to order-agnostic LMs, as the tokens in order-agnostic LMs are not generated sequentially. In this work, we introduce PATTERN-MARK, a pattern-…

Cited by 2SourcePDFScholar
2025

Federated Continuous Category Discovery and Learning

ICCV 2025poster

Federated Learning (FL) studies often assume a static data distribution, whereas real-world scenarios involve dynamic changes. To address this gap, we study Federated Continuous Category Discovery and Learning (FC^2DL), an essential yet underexplored problem that enables FL models to evolve continuo…

Cited by 0SourcePDFScholar
2025

TimeCMA: Towards LLM-Empowered Multivariate Time Series Forecasting via Cross-Modality Alignment

AAAI 2025technical

Multivariate time series forecasting (MTSF) aims to learn temporal dynamics among variables to forecast future time series. Existing statistical and deep learning-based methods suffer from limited learnable parameters and small-scale training data. Recently, large language models (LLMs) combining ti…

2025

Towards Cross-Modality Modeling for Time Series Analytics: A Survey in the LLM Era

IJCAI 2025

The proliferation of edge devices has generated an unprecedented volume of time series data across different domains, motivating a variety of well-customized methods. Recently, Large Language Models (LLMs) have emerged as a new paradigm for time series analytics by leveraging the shared sequential n

2024

De-Diffusion Makes Text a Strong Cross-Modal Interface

CVPR 2024poster

We demonstrate text as a strong cross-modal interface. Rather than relying on deep embeddings to connect image and language as the interface representation our approach represents an image as text from which we enjoy the interpretability and flexibility inherent to natural language. We employ an aut…

2024

Discovery of the Hidden World with Large Language Models

NeurIPS 2024poster

Revealing the underlying causal mechanisms in the real world is the key to the development of science. Despite the progress in the past decades, traditional causal discovery approaches (CDs) mainly rely on high-quality measured variables, usually given by human experts, to find causal relations. The…

Cited by 0SourcePDFScholar
2024

Your Vision-Language Model Itself Is a Strong Filter: Towards High-Quality Instruction Tuning with Data Selection

ACL 2024findings

Data selection in instruction tuning emerges as a pivotal process for acquiring high-quality data and training instruction-following large language models (LLMs), but it is still a new and unexplored research area for vision-language models (VLMs). Existing data selection approaches on LLMs either r…

2024

ZeroMark: Towards Dataset Ownership Verification without Disclosing Watermark

NeurIPS 2024poster

High-quality public datasets significantly prompt the prosperity of deep neural networks (DNNs). Currently, dataset ownership verification (DOV), which consists of dataset watermarking and ownership verification, is the only feasible solution to protect their copyright by preventing unauthorized use…

2023

Deja Vu: Continual Model Generalization for Unseen Domains

ICLR 2023poster

In real-world applications, deep learning models often run in non-stationary environments where the target data distribution continually shifts over time. There have been numerous domain adaptation (DA) methods in both online and offline modes to improve cross-domain adaptation ability. However, the…

Cited by 27SourcePDFScholar
2023

LEF: Late-to-Early Temporal Fusion for LiDAR 3D Object Detection

IROS 2023poster

We propose a late-to-early recurrent feature fusion scheme for 3D object detection using temporal LiDAR point clouds. Our main motivation is fusing object-aware latent embeddings into the early stages of a 3D object detector. This feature fusion strategy enables the model to better capture the shape…

Cited by 3SourceScholar
2023

Lidar Augment: Searching for Scalable 3D LiDAR Data Augmentations

ICRA 2023poster

Data augmentations are important for training high-performance 3D object detectors that use point clouds. Despite recent efforts on designing new data augmentations, perhaps surprisingly, most current state-of-the-art 3D detectors only rely on a few simple data augmentations. In particular, differen…

Cited by 12SourceScholar
2023

MoDAR: Using Motion Forecasting for 3D Object Detection in Point Cloud Sequences

CVPR 2023poster

Occluded and long-range objects are ubiquitous and challenging for 3D object detection. Point cloud sequence data provide unique opportunities to improve such cases, as an occluded or distant object can be observed from different viewpoints or gets better visibility over time. However, the efficienc…

Cited by 15SourcePDFScholar
2022

LidarNAS: Unifying and Searching Neural Architectures for 3D Point Clouds

ECCV 2022poster

"Developing neural models that accurately understand objects in 3D point clouds is essential for the success of robotics and autonomous driving. However, arguably due to the higher-dimensional nature of the data (as compared to images), existing neural architectures exhibit a large variety in their…

Cited by 6SourcePDFScholar
2022

Multi-Class 3D Object Detection with Single-Class Supervision

ICRA 2022poster

While multi-class 3D detectors are needed in many robotics applications, training them with fully labeled datasets can be expensive in labeling cost. An alternative approach is to have targeted single-class labels on disjoint data samples. In this paper, we are interested in training a multi-class 3…

Cited by 2SourceScholar
2022

PolyLoss: A Polynomial Expansion Perspective of Classification Loss Functions

ICLR 2022poster

Cross-entropy loss and focal loss are the most common choices when training deep neural networks for classification problems. Generally speaking, however, a good loss function can take on much more flexible forms, and should be tailored for different tasks and datasets. Motivated by how functions ca…

Cited by 239SourcePDFScholar
2022

SWFormer: Sparse Window Transformer for 3D Object Detection in Point Clouds

ECCV 2022poster

"3D object detection in point clouds is a core component for modern robotics and autonomous driving systems. A key challenge in 3D object detection comes from the inherent sparse nature of point occupancy within the 3D scene. In this paper, we propose Sparse Window Transformer (SWFormer ), a scalabl…

Cited by 140SourcePDFScholar
2022

Scene Transformer: A unified architecture for predicting future trajectories of multiple agents

ICLR 2022poster

Predicting the motion of multiple agents is necessary for planning in dynamic environments. This task is challenging for autonomous driving since agents (e.g., vehicles and pedestrians) and their associated behaviors may be diverse and influence one another. Most prior work have focused on predictin…

Cited by 0SourcePDFScholar
2021

Large Scale Interactive Motion Forecasting for Autonomous Driving: The Waymo Open Motion Dataset

ICCV 2021poster

As autonomous driving systems mature, motion forecasting has received increasing attention as a critical requirement for planning. Of particular importance are interactive situations such as merges, unprotected turns, etc., where predicting individual object motion is not sufficient. Joint predictio…

Cited by 624PDFScholar
2021

Progressive Stage-Wise Learning for Unsupervised Feature Representation Enhancement

CVPR 2021poster

Unsupervised learning methods have recently shown their competitiveness against supervised training. Typically, these methods use a single objective to train the entire network. But one distinct advantage of unsupervised over supervised learning is that the former possesses more variety and freedom…

Cited by 6PDFScholar
2020

Are Labels Necessary for Neural Architecture Search?

ECCV 2020poster

Existing neural network architectures in computer vision --- whether designed by humans or by machines --- were typically found using both images and their associated labels. In this paper, we ask the question: can we find high-quality neural architectures using only images, but no human-annotated l…

2019

Adversarial Attacks Beyond the Image Space

CVPR 2019oral

Generating adversarial examples is an intriguing problem and an important way of understanding the working mechanism of deep neural networks. Most existing approaches generated perturbations in the image space, i.e., each pixel can be modified independently. However, in this paper we pay special att…

Cited by 174PDFScholar
2019

Auto-DeepLab: Hierarchical Neural Architecture Search for Semantic Image Segmentation

CVPR 2019oral

Recently, Neural Architecture Search (NAS) has successfully identified neural network architectures that exceed human designed ones on large-scale image classification. In this paper, we study NAS for semantic image segmentation. Existing works often focus on searching the repeatable cell structure,…

Cited by 1290PDFcodeScholar
2018

Few-Shot Image Recognition by Predicting Parameters From Activations

CVPR 2018poster

In this paper, we are interested in the few-shot learning problem. In particular, we focus on a challenging scenario where the number of categories is large and the number of examples per novel category is very limited, e.g. 1, 2, or 3. Motivated by the close relationship between the parameters and…

Cited by 680SourcePDFScholar
2018

Progressive Neural Architecture Search

ECCV 2018poster

We propose a new method for learning the structure of convolutional neural networks (CNNs) that is more efficient than recent state-of-the-art methods based on reinforcement learning and evolutionary algorithms. Our approach uses a sequential model-based optimization (SMBO) strategy, in which we sea…

2017

Recurrent Multimodal Interaction for Referring Image Segmentation

ICCV 2017poster

In this paper we are interested in the problem of image segmentation given natural language descriptions, i.e. referring expressions. Existing works tackle this problem by first modeling images and sentences independently and then segment images by combining these two types of representations. We ar…

Cited by 296PDFcodeScholar
2017

SORT: Second-Order Response Transform for Visual Recognition

ICCV 2017poster

In this paper, we reveal the importance and benefits of introducing second-order operations into deep neural networks. We propose a novel approach named Second-Order Response Transform (SORT), which appends element-wise product transform to the linear sum of a two-branch network module. A direct adv…

Cited by 67PDFcodeScholar
2017

ScaleNet: Guiding Object Proposal Generation in Supermarkets and Beyond

ICCV 2017poster

Motivated by product detection in supermarkets, this paper studies the problem of object proposal generation in supermarket images and other natural images. We argue that estimation of object scales in images is helpful for generating object proposals, especially for supermarket images where object…

Cited by 56PDFScholar
2015

Rent3D: Floor-Plan Priors for Monocular Layout Estimation

CVPR 2015poster

The goal of this paper is to enable a 3D "virtual-tour" of an apartment given a small set of monocular images of different rooms, as well as a 2D floor plan. We frame the problem as inference in a Markov Random Field which reasons about the layout of each room and its relative pose (3D rotation and…

Cited by 177SourcePDFScholar