Bang Liu

Google Scholar

Biographie

Bang Liu est professeur adjoint au Département d'informatique et de recherche opérationnelle (DIRO) de l'Université de Montréal. Il est membre du Laboratoire de recherche appliquée en linguistique informatique (RALI) du DIRO, membre associé de Mila – Institut québécois d'intelligence artificielle, et titulaire d'une chaire en IA Canada-CIFAR.

Il a obtenu un baccalauréat en ingénierie de l'Université des sciences et technologies de Chine (USTC) en 2013, ainsi qu’une maîtrise ès sciences et un doctorat de l'Université de l'Alberta en 2015 et en 2020, respectivement. Ses recherches portent principalement sur le traitement du langage naturel, l'apprentissage multimodal et incarné, la théorie et les techniques de l'intelligence artificielle (par exemple, la compréhension et l'amélioration de grands modèles de langage) et l'intelligence artificielle pour la science (par exemple, la santé, la science des matériaux et la radiologie).

Étudiants actuels

Doctorat - UdeM

Postdoctorat - UdeM

Doctorat - UdeM

Yizhan Li

Doctorat - UdeM

Kyle Roth

Doctorat - UdeM

Haochen Shi

Doctorat - UdeM

Xiran Song

Doctorat - UdeM

Github

Google Scholar

Jia'ao Sun

Doctorat - UdeM

Doctorat - UdeM

Doctorat - UdeM

Sifan Wu

Doctorat - UdeM

Dekun Wu

Doctorat - UdeM

Mengyang Xiong

Stagiaire de recherche - McGill

Huan Zhang

Maîtrise recherche - UdeM

Révolutionner la science des matériaux grâce au traitement du langage naturel : présentation de MatSci-NLP et de HoneyBee

Google Scholar

Armin Zolfagharidariani

Maîtrise recherche - UdeM

Github

Billets de blogue

MatSci-Instruct and HoneyBee training workflow.

21 octobre 2024

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Bang Liu

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Publications

OSCAR: Operating System Control via State-Aware Reasoning and Re-Planning

Xiaoqiang Wang

Large language models (LLMs) and large multimodal models (LMMs) have shown great potential in automating complex tasks like web browsing and… (voir plus) gaming. However, their ability to generalize across diverse applications remains limited, hindering broader utility. To address this challenge, we present OSCAR: Operating System Control via state-Aware reasoning and Re-planning. OSCAR is a generalist agent designed to autonomously navigate and interact with various desktop and mobile applications through standardized controls, such as mouse and keyboard inputs, while processing screen images to fulfill user commands. OSCAR translates human instructions into executable Python code, enabling precise control over graphical user interfaces (GUIs). To enhance stability and adaptability, OSCAR operates as a state machine, equipped with error-handling mechanisms and dynamic task re-planning, allowing it to efficiently adjust to real-time feedback and exceptions. We demonstrate OSCAR’s effectiveness through extensive experiments on diverse benchmarks across desktop and mobile platforms, where it transforms complex workflows into simple natural language commands, significantly boosting user productivity. Our code will be open-source upon publication.

2025-01-21

ICLR.cc/2025/Conference (poster)

VCR: A Task for Pixel-Level Complex Reasoning in Vision Language Models via Restoring Occluded Text

Ge Zhang

Sai Rajeswar

We introduce Visual Caption Restoration (VCR), a novel vision-language task that challenges models to accurately restore partially obscured … (voir plus)texts using pixel-level hints within images. This task stems from the observation that text embedded in images is intrinsically different from common visual elements and natural language due to the need to align the modalities of vision, text, and text embedded in images. While numerous works have integrated text embedded in images into visual question-answering tasks, approaches to these tasks generally rely on optical character recognition or masked language modeling, thus reducing the task to mainly text-based processing. However, text-based processing becomes ineffective in VCR as accurate text restoration depends on the combined information from provided images, context, and subtle cues from the tiny exposed areas of masked texts. We develop a pipeline to generate synthetic images for the VCR task using image-caption pairs, with adjustable caption visibility to control the task difficulty. With this pipeline, we construct a dataset for VCR called VCR-Wiki using images with captions from Wikipedia, comprising 2.11M English and 346K Chinese entities in both easy and hard split variants. Our results reveal that current vision language models significantly lag behind human performance in the VCR task, and merely fine-tuning the models on our dataset does not lead to notable improvements. We release VCR-Wiki and the data construction code to facilitate future research.

2024-10-08

NeurIPS.cc/2024/Workshop/Sys2-Reasoning (poster)

doi.org

HoneyComb: A Flexible LLM-Based Agent System for Materials Science

Huan Zhang

Yu Song

Ziyu Hou

Santiago Miret

The emergence of specialized large language models (LLMs) has shown promise in addressing complex tasks in materials science. Many LLMs, how… (voir plus)ever, often struggle with the distinct complexities of materials science tasks, such as computational challenges, and rely heavily on outdated implicit knowledge, leading to inaccuracies and hallucinations. To address these challenges, we introduce HoneyComb, the first LLM-based agent system specifically designed for materials science. HoneyComb leverages a reliable, high-quality materials science knowledge base (MatSciKB) and a sophisticated tool hub (ToolHub) tailored specifically for materials science to enhance its reasoning and computational capabilities. MatSciKB is a curated, structured knowledge collection based on reliable literature, while ToolHub employs an Inductive Tool Construction method to generate, decompose, and refine API tools for materials science. Additionally, HoneyComb leverages a retriever module that adaptively selects the appropriate knowledge source or tools for specific tasks, thereby ensuring accuracy and relevance. Our results demonstrate that HoneyComb significantly outperforms baseline models across various tasks in materials science, effectively bridging the gap between current LLM capabilities and the specialized needs of this domain. Furthermore, our adaptable framework can be easily extended to other scientific domains, highlighting its potential for broad applicability in advancing scientific research and applications.

2024-10-06

NeurIPS.cc/2024/Workshop/AI4Mat (spotlight)

Enhancing Agent Learning through World Dynamics Modeling

Xingdi Yuan

Large language models (LLMs) have been increasingly applied to tasks in language understanding and interactive decision-making, with their i… (voir plus)mpressive performance largely attributed to the extensive domain knowledge embedded within them. However, the depth and breadth of this knowledge can vary across domains. Many existing approaches assume that LLMs possess a comprehensive understanding of their environment, often overlooking potential gaps in their grasp of actual world dynamics. To address this, we introduce Discover, Verify, and Evolve (DiVE), a framework that discovers world dynamics from a small number of demonstrations, verifies the accuracy of these dynamics, and evolves new, advanced dynamics tailored to the current situation. Through extensive evaluations, we assess the impact of each component on performance and compare the dynamics generated by DiVE to human-annotated dynamics. Our results show that LLMs guided by DiVE make more informed decisions, achieving rewards comparable to human players in the Crafter environment and surpassing methods that require prior task-specific training in the MiniHack environment.

2024-07-24

arXiv (Cornell University) (prépublication)

doi.org

arxiv.org

T2VIndexer: A Generative Video Indexer for Efficient Text-Video Retrieval

Yili Li

Jing Yu

Keke Gai

Gang Xiong

Qi Wu

Current text-video retrieval methods mainly rely on cross-modal matching between queries and videos to calculate their similarity scores, wh… (voir plus)ich are then sorted to obtain retrieval results. This method considers the matching between each candidate video and the query, but it incurs a significant time cost and will increase notably with the increase of candidates. Generative models are common in natural language processing and computer vision, and have been successfully applied in document retrieval, but their application in multimodal retrieval remains unexplored. To enhance retrieval efficiency, in this paper, we introduce a model-based video indexer named T2VIndexer, which is a sequence-to-sequence generative model directly generating video identifiers and retrieving candidate videos with constant time complexity. T2VIndexer aims to reduce retrieval time while maintaining high accuracy. To achieve this goal, we propose video identifier encoding and query-identifier augmentation approaches to represent videos as short sequences while preserving their semantic information. Our method consistently enhances the retrieval efficiency of current state-of-the-art models on four standard datasets. It enables baselines with only 30%-50% of the original retrieval time to achieve better retrieval performance on MSR-VTT (+1.0%), MSVD (+1.8%), ActivityNet (+1.5%), and DiDeMo (+0.2%). The code is available at https://anonymous.4open.science/r/T2VIndexer-40BE.

2024-07-19

acmmm.org/ACMMM/2024/Conference (présentation orale)

EiG-Search: Generating Edge-Induced Subgraphs for GNN Explanation in Linear Time

Shengyao Lu

Keith G Mills

Jiao He

Di Niu

2024-07-07

Proceedings of the 41st International Conference on Machine Learning (publié)

proceedings.mlr.press

GOAt: Explaining Graph Neural Networks via Graph Output Attribution

Shengyao Lu

Keith G Mills

Jiao He

Di Niu

Understanding the decision-making process of Graph Neural Networks (GNNs) is crucial to their interpretability. Most existing methods for ex… (voir plus)plaining GNNs typically rely on training auxiliary models, resulting in the explanations remain black-boxed. This paper introduces Graph Output Attribution (GOAt), a novel method to attribute graph outputs to input graph features, creating GNN explanations that are faithful, discriminative, as well as stable across similar samples. By expanding the GNN as a sum of scalar products involving node features, edge features and activation patterns, we propose an efficient analytical method to compute contribution of each node or edge feature to each scalar product and aggregate the contributions from all scalar products in the expansion form to derive the importance of each node and edge. Through extensive experiments on synthetic and real-world data, we show that our method not only outperforms various state-of-the-art GNN explainers in terms of the commonly used fidelity metric, but also exhibits stronger discriminability, and stability by a remarkable margin.

2024-01-15

ICLR.cc/2024/Conference (poster)