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Weiwei Sun

39 accepted papers

2026

CO-Bench: Benchmarking Language Model Agents in Algorithm Search for Combinatorial Optimization

AAAI 2026technical

Although LLM-based agents have attracted significant attention in domains such as software engineering and machine learning research, their role in advancing combinatorial optimization (CO) remains relatively underexplored. This gap underscores the need for a deeper understanding of their potential

Cited by 0SourcePDFScholar
2026

CoMind: Towards Community-Driven Agents for Machine Learning Engineering

ICLR 2026poster

Large language model (LLM) agents show promise in automating machine learning (ML) engineering. However, existing agents typically operate in isolation on a given research problem, without engaging with the broader research community, where human researchers often gain insights and contribute by sha…

Cited by 0SourcecodeScholar
2026

FrontierCO: Real-World and Large-Scale Evaluation of Machine Learning Solvers for Combinatorial Optimization

ICLR 2026poster

Machine learning (ML) has shown promise for tackling combinatorial optimization (CO), but much of the reported progress relies on small-scale, synthetic benchmarks that fail to capture real-world structure and scale. A core limitation is that ML methods are typically trained and evaluated on synthet…

Cited by 0SourcecodeScholar
2026

HAD: Hallucination-Aware Diffusion Priors for 3D Reconstruction

CVPR 2026

Diffusion priors have recently demonstrated strong capability in enhancing the quality of sparse-view 3D reconstruction by augmenting training views at novel viewpoints, but they inevitably introduce hallucinated content-- artifacts inconsistent with the input views -- into the final 3D model. To ad

Cited by 0SourceScholar
2026

ZeroGR: A Generalizable and Scalable Framework for Zero-Shot Generative Retrieval

ICLR 2026poster

Generative retrieval (GR) reformulates information retrieval (IR) by framing it as the generation of document identifiers (docids), thereby enabling an end-to-end optimization and seamless integration with generative language models (LMs). Despite notable progress under supervised training, GR still…

Cited by 0SourcecodeScholar
2025

Compositional Syntactico-SemBanking for English as a Second or Foreign Language

ACL 2025finding

Despite the widespread use of English as a Second or Foreign Language (ESFL), developing syntactico-semantic representations for it is limited — the irregularities in ESFL complicate systematic composition and subsequently the derivation of its semantics.This paper draws on constructivism and propos…

Cited by 0SourcePDFScholar
2025

Enhancing Training Data Attribution with Representational Optimization

NeurIPS 2025spotlight

Training data attribution (TDA) methods aim to measure how training data impacts a model's predictions. While gradient-based attribution methods, such as influence functions, offer theoretical grounding, their computational costs make them impractical for large-scale applications. Representation-b…

Cited by 0SourcecodeScholar
2025

Improving Retrieval-Augmented Generation through Multi-Agent Reinforcement Learning

NeurIPS 2025poster

Retrieval-augmented generation (RAG) is widely utilized to incorporate external knowledge into large language models, thereby enhancing factuality and reducing hallucinations in question-answering (QA) tasks. A standard RAG pipeline consists of several components, such as query rewriting, document r…

Cited by 0SourcecodeScholar
2025

Unified Graph and Hypergraph Neural Network for Next-item Recommendation

ICASSP 2025accepted

The task of next-item recommendation is a crucial component in recommendation systems. The challenge of this task lies in extracting complex interaction information from users’ historical interactions with items. While prior research has transformed users’ interaction histories into graphs and hyper…

Cited by 0SourceScholar
2024

"PointNeRF++: A multi-scale, point-based Neural Radiance Field"

ECCV 2024poster

"Point clouds offer an attractive source of information to complement images in neural scene representations, especially when few images are available. Neural rendering methods based on point clouds do exist, but they do not perform well when the point cloud is sparse or incomplete, which is often t…

2024

3D Gaussian Splatting as Markov Chain Monte Carlo

NeurIPS 2024spotlight

While 3D Gaussian Splatting has recently become popular for neural rendering, current methods rely on carefully engineered cloning and splitting strategies for placing Gaussians, which does not always generalize and may lead to poor-quality renderings. For many real-world scenes this leads to their…

2024

Generate-then-Ground in Retrieval-Augmented Generation for Multi-hop Question Answering

ACL 2024long

Multi-Hop Question Answering (MHQA) task presents a significant challenge for large language models (LLMs) due to the intensive knowledge required. Current solutions, like Retrieval-Augmented Generation, typically retrieve potential documents from an external corpus to read an answer. However, the p…

2024

How Large Language Models Encode Context Knowledge? A Layer-Wise Probing Study

COLING 2024main

Previous work has showcased the intriguing capability of large language models (LLMs) in retrieving facts and processing context knowledge. However, only limited research exists on the layer-wise capability of LLMs to encode knowledge, which challenges our understanding of their internal mechanisms.…

2024

Improving the Robustness of Large Language Models via Consistency Alignment

COLING 2024main

Large language models (LLMs) have shown tremendous success in following user instructions and generating helpful responses. Nevertheless, their robustness is still far from optimal, as they may generate significantly inconsistent responses due to minor changes in the verbalized instructions. Recent…

2024

Knowing What LLMs DO NOT Know: A Simple Yet Effective Self-Detection Method

NAACL 2024long

Large Language Models (LLMs) have shown great potential in Natural Language Processing (NLP) tasks.However, recent literature reveals that LLMs hallucinate intermittently, which impedes their reliability for further utilization. In this paper, we propose a novel self-detection method to detect which…

2024

Lagrangian Hashing for Compressed Neural Field Representations

ECCV 2024poster

"We present Lagrangian Hashing, a representation for neural fields combining the characteristics of fast training NeRF methods that rely on Eulerian grids (i.e. InstantNGP), with those that employ points equipped with features as a way to represent information (e.g. 3D Gaussian Splatting or PointNeR…

Cited by 1SourcePDFScholar
2024

MAIR: A Massive Benchmark for Evaluating Instructed Retrieval

EMNLP 2024main

Recent information retrieval (IR) models are pre-trained and instruction-tuned on massive datasets and tasks, enabling them to perform well on a wide range of tasks and potentially generalize to unseen tasks with instructions. However, existing IR benchmarks focus on a limited scope of tasks, making…

2024

MEFT: Memory-Efficient Fine-Tuning through Sparse Adapter

ACL 2024long

Parameter-Efficient Fine-tuning (PEFT) facilitates the fine-tuning of Large Language Models (LLMs) under limited resources. However, the fine-tuning performance with PEFT on complex, knowledge-intensive tasks is limited due to the constrained model capacity, which originates from the limited number…

2024

Modeling Route Representation With Mixed-Scale Hierarchical Transformer

ICASSP 2024accepted

Modeling route representation aims to obtain contextual representations of an entire route for various traffic-related tasks. In reality, spatial-temporal data often exhibits multi-scale characteristics, which are utilized by many studies to enhance their performance. However, there is still a lack…

Cited by 0SourceScholar
2024

Trajectory set Empowered Hypergraph Transformer for Mobile Sensor Based Traffic Prediction

ICASSP 2024accepted

Traffic speed prediction is vital for intelligent transportation systems. However, most existing methods focus on costly static sensors. In contrast, utilizing GPS devices from vehicles as mobile sensors offers a cost-effective means to gather dynamic traffic data. Despite the presence of historical…

Cited by 0SourceScholar
2023

Answering Ambiguous Questions via Iterative Prompting

ACL 2023long

In open-domain question answering, due to the ambiguity of questions, multiple plausible answers may exist. To provide feasible answers to an ambiguous question,one approach is to directly predict all valid answers, but this can struggle with balancing relevance and diversity. An alternative is to g…

2023

ContiFormer: Continuous-Time Transformer for Irregular Time Series Modeling

NeurIPS 2023poster

Modeling continuous-time dynamics on irregular time series is critical to account for data evolution and correlations that occur continuously. Traditional methods including recurrent neural networks or Transformer models leverage inductive bias via powerful neural architectures to capture complex pa…

2023

Contrastive Learning Reduces Hallucination in Conversations

AAAI 2023technical

Pre-trained language models (LMs) store knowledge in their parameters and can generate informative responses when used in conversational systems. However, LMs suffer from the problem of “hallucination:” they may generate plausible-looking statements that are irrelevant or factually incorrect. To add…

2023

DiQAD: A Benchmark Dataset for Open-domain Dialogue Quality Assessment

EMNLP 2023long findings

Dialogue assessment plays a critical role in the development of open-domain dialogue systems. Existing work are uncapable of providing an end-to-end and human-epistemic assessment dataset, while they only provide sub-metrics like coherence or the dialogues are conversed between annotators far from r…

Cited by 0SourcecodeScholar
2023

Is ChatGPT Good at Search? Investigating Large Language Models as Re-Ranking Agents

EMNLP 2023long main

Large Language Models (LLMs) have demonstrated remarkable zero-shot generalization across various language-related tasks, including search engines. However, existing work utilizes the generative ability of LLMs for Information Retrieval (IR) rather than direct passage ranking. The discrepancy betwe…

Cited by 0SourcecodeScholar
2023

Learning to Tokenize for Generative Retrieval

NeurIPS 2023poster

As a new paradigm in information retrieval, generative retrieval directly generates a ranked list of document identifiers (docids) for a given query using generative language models (LMs). How to assign each document a unique docid (denoted as document tokenization) is a critical problem, because it…

Cited by 112SourcePDFScholar
2023

RADE: Reference-Assisted Dialogue Evaluation for Open-Domain Dialogue

ACL 2023long

Evaluating open-domain dialogue systems is challenging for reasons such as the one-to-many problem, i.e., many appropriate responses other than just the golden response. As of now, automatic evaluation methods need better consistency with humans, while reliable human evaluation can be time- and cost…

2022

Multi-Agent Reinforcement Learning for Traffic Signal Control through Universal Communication Method

IJCAI 2022poster

How to coordinate the communication among intersections effectively in real complex traffic scenarios with multi-intersection is challenging. Existing approaches only enable the communication in a heuristic manner without considering the content/importance of information to be shared. In this paper…

2021

Canonical Capsules: Self-Supervised Capsules in Canonical Pose

NeurIPS 2021poster

We propose a self-supervised capsule architecture for 3D point clouds. We compute capsule decompositions of objects through permutation-equivariant attention, and self-supervise the process by training with pairs of randomly rotated objects. Our key idea is to aggregate the attention masks into sema…

2021

Dynamic Lane Traffic Signal Control with Group Attention and Multi-Timescale Reinforcement Learning

IJCAI 2021poster

Traffic signal control has achieved significant success with the development of reinforcement learning. However, existing works mainly focus on intersections with normal lanes with fixed outgoing directions. It is noticed that some intersections actually implement dynamic lanes, in addition to norma…

Cited by 19SourcePDFScholar
2021

Universal Semantic Tagging for English and Mandarin Chinese

NAACL 2021long

Universal Semantic Tagging aims to provide lightweight unified analysis for all languages at the word level. Though the proposed annotation scheme is conceptually promising, the feasibility is only examined in four Indo–European languages. This paper is concerned with extending the annotation scheme…

2020

ACNe: Attentive Context Normalization for Robust Permutation-Equivariant Learning

CVPR 2020poster

Many problems in computer vision require dealing with sparse, unordered data in the form of point clouds. Permutation-equivariant networks have become a popular solution - they operate on individual data points with simple perceptrons and extract contextual information with global pooling. This can…

Cited by 196PDFcodeScholar
2020

Trajectory Similarity Learning with Auxiliary Supervision and Optimal Matching

IJCAI 2020poster

Trajectory similarity computation is a core problem in the field of trajectory data queries. However, the high time complexity of calculating the trajectory similarity has always been a bottleneck in real-world applications. Learning-based methods can map trajectories into a uniform embedding space…

2019

Linearized Multi-Sampling for Differentiable Image Transformation

ICCV 2019oral

We propose a novel image sampling method for differentiable image transformation in deep neural networks. The sampling schemes currently used in deep learning, such as Spatial Transformer Networks, rely on bilinear interpolation, which performs poorly under severe scale changes, and more importantly…

Cited by 27PDFcodeScholar
2019

Unified Visual-Semantic Embeddings: Bridging Vision and Language With Structured Meaning Representations

CVPR 2019oral

We propose the Unified Visual-Semantic Embeddings (Unified VSE) for learning a joint space of visual representation and textual semantics. The model unifies the embeddings of concepts at different levels: objects, attributes, relations, and full scenes. We view the sentential semantics as a combinat…

Cited by 221PDFcodeScholar