Zimu Lu

dblp:306/4748 · DBLP profile ↗
← Back
17ranked-venue papers
4as first author
17since 2021 · last 2026
0000-0001-8479-2807ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Artificial intelligence and machine learning · 12 · 3 first-author · 12 since 2021Graphics, computer vision, multimedia, augmented reality and games · 5 · 1 first-author · 5 since 2021Databases, data management, data science and information retrieval · 1 · 1 since 2021
YearPublicationVenuePosition
2026 From Solver to Tutor: Evaluating the Pedagogical Intelligence of LLMs with KMP-Bench
abstract
Large Language Models (LLMs) show significant potential in AI mathematical tutoring, yet current evaluations often rely on simplistic metrics or narrow pedagogical scenarios, failing to assess comprehensive, multi-turn teaching effectiveness. In this paper, we introduce KMP-Bench, a comprehensive K-8 Mathematical Pedagogical Benchmark designed to assess LLMs from two complementary perspectives. The first module, KMP-Dialogue, evaluates holistic pedagogical capabilities against six core principles (e.g., Challenge, Explanation, Feedback), leveraging a novel multi-turn dialogue dataset constructed by weaving together diverse pedagogical components. The second module, KMP-Skills, provides a granular assessment of foundational tutoring abilities, including multi-turn problem-solving, error detection and correction, and problem generation. Our evaluations on KMP-Bench reveal a key disparity: while leading LLMs excel at tasks with verifiable solutions, they struggle with the nuanced application of pedagogical principles. Additionally, we present KMP-Pile, a large-scale (150K) dialogue dataset. Models fine-tuned on KMP-Pile show substantial improvement on KMP-Bench, underscoring the value of pedagogically-rich training data for developing more effective AI math tutors.
Weikang Shi, Houxing Ren, Junting Pan, Aojun Zhou, Ke Wang 0036, Zimu Lu, Yunqiao Yang 0002, Linda Wei, Mingjie Zhan, Hongsheng Li 0001
AAAI6
2026 Towards Robust Real-World Spreadsheet Understanding with Multi-Agent Multi-Format Reasoning
abstract
Houxing Ren, Mingjie Zhan, Zimu Lu, Ke Wang, Yunqiao Yang, Haotian Hou, Hongsheng Li. Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers). 2026.
Houxing Ren, Mingjie Zhan, Zimu Lu, Ke Wang 0036, Yunqiao Yang 0002, Haotian Hou, Hongsheng Li 0001
ACL (1)3
2026 MathCanvas: Intrinsic Visual Chain-of-Thought for Multimodal Mathematical Reasoning
abstract
Weikang Shi, Aldrich Yu, Rongyao Fang, Houxing Ren, Ke Wang, Aojun Zhou, Changyao Tian, Xinyu Fu, Yuxuan Hu, Zimu Lu, Linjiang Huang, Si Liu, Rui Liu, Hongsheng Li. Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers). 2026.
Weikang Shi, Aldrich Yu, Rongyao Fang, Houxing Ren, Ke Wang 0036, Aojun Zhou, Changyao Tian, Xinyu Fu 0004, Zimu Lu, Linjiang Huang, Si Liu 0001, Rui Liu 0019, Hongsheng Li 0001
ACL (1)10
2026 Medical VLP Model Is Vulnerable: Toward Multimodal Adversarial Attack on Large Medical Vision-Language Models
abstract
Medical Visual Question Answering (Medical VQA) is an essential task that facilitates the automated interpretation of complex clinical imagery with corresponding textual questions, thereby supporting both clinicians and patients in making informed medical decisions. With the rapid progress of Vision-Language Pretraining (VLP) in general domains, the development of medical VLP models has emerged as a rapidly growing interdisciplinary area at the intersection of artificial intelligence (AI) and healthcare. However, few works have been proposed to evaluate the adversarial robustness of medical VLP models, which faces two primary challenges: (1) the complexity of medical texts, stemming from the presence of terminologies, poses significant challenges for models in comprehending the text for adversarial attack; (2) the diversity of medical images arises from the variety of anatomical regions depicted, which requires models to determine critical anatomical regions for attack. In this paper, we propose a novel multimodal adversarial attack generator for evaluating the robustness of medical VLP models. Specifically, for the complexity of medical texts, we integrate medical knowledge when crafting text adversarial samples, which can facilitate the terminologies understanding and adversarial strength; for the diversity of medical images, we divide the anatomical regions into either global or local regions in medical images, which are determined by learned balance weights for perturbations. Our experimental study not only provides a quantitative understanding in medical VLP models, but also underscores the critical need for thorough safety evaluations before implementing them in real-world medical applications.
Zimu Lu, Ning Xu 0003, Hongshuo Tian, Lanjun Wang, Anan Liu
IEEE Trans. Circuits Syst. Video Technol.1
2026 MMToT: Multi-Modal Token-of-Thought Reasoning for Large Models
abstract
With the development of Large models (LMs), recent methods tend to leverage them to complete various downstream tasks, like VQA and image caption. A typical method is Chain-of-Thought (CoT) prompting, which improves the reasoning abilities of LMs by providing intermediate steps. However, existing CoT prompts have two main drawbacks: 1) They typically represent CoT through multiple sentences, which often introduce irrelevant textual or visual context that may confuse LMs. 2) The current CoT methods fail to consider how the contributions of different tokens vary for answer inference. For this, we propose the Multi-Modal Token-of-Thought (MMToT), a novel token-level prompt method to improve LMs' multi-modal reasoning capabilities. Furthermore, MMToT stress on two strengths against CoT: 1) To prevent LMs from being affected by irrelevant contexts, we propose to extract explicit multi-modal tokens rather than sentences to construct MMToT, enhancing the reliability of generated answers. 2) To ensure that LMs prioritize tokens with high contribution scores during answer generation, we propose a confident decision-making module to evaluate and integrate each token's contribution in MMToT. Compared to existing methods, the proposed MMToT demonstrates superior performance on Science-QA, MATH, OKVQA, and VQA-introspect datasets. Furthermore, ablation studies and visualization results validate the effectiveness and interpretability of MMToT.
Ning Xu 0003, Zimu Lu, Hongshuo Tian, Bolun Zheng, Jinbo Cao, Anan Liu
IEEE Trans. Multim.2
2025 Alignment with Fill-In-the-Middle for Enhancing Code Generation
abstract
Houxing Ren, Zimu Lu, Weikang Shi, Haotian Hou, Yunqiao Yang, Ke Wang, Aojun Zhou, Junting Pan, Mingjie Zhan, Hongsheng Li. Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing. 2025.
Houxing Ren, Zimu Lu, Weikang Shi, Haotian Hou, Yunqiao Yang 0002, Ke Wang 0036, Aojun Zhou, Junting Pan, Mingjie Zhan, Hongsheng Li 0001
EMNLP2
2025 MathCoder2: Better Math Reasoning from Continued Pretraining on Model-translated Mathematical Code
abstract
Code has been shown to be effective in enhancing the mathematical reasoning abilities of large language models due to its precision and accuracy. Previous works involving continued mathematical pretraining often include code that utilizes math-related packages, which are primarily designed for fields such as engineering, machine learning, signal processing, or module testing, rather than being directly focused on mathematical reasoning. In this paper, we introduce a novel method for generating mathematical code accompanied with corresponding reasoning steps for continued pretraining. Our approach begins with the construction of a high-quality mathematical continued pretraining dataset by incorporating math-related web data, code using mathematical packages, math textbooks, and synthetic data. Next, we construct reasoning steps by extracting LaTeX expressions, the conditions needed for the expressions, and the results of the expressions from the previously collected dataset. Based on this extracted information, we generate corresponding code to accurately capture the mathematical reasoning process. Appending the generated code to each reasoning step results in data consisting of paired natural language reasoning steps and their corresponding code. Combining this data with the original dataset results in a 19.2B-token high-performing mathematical pretraining corpus, which we name MathCode-Pile. Training several popular base models with this corpus significantly improves their mathematical abilities, leading to the creation of the MathCoder2 family of models. All of our data processing and training code is open-sourced, ensuring full transparency and easy reproducibility of the entire data collection and training pipeline.
Zimu Lu, Aojun Zhou, Ke Wang 0036, Houxing Ren, Weikang Shi, Junting Pan, Mingjie Zhan, Hongsheng Li 0001
ICLR1
2025 WebGen-Bench: Evaluating LLMs on Generating Interactive and Functional Websites from Scratch
abstract
LLM‑based agents have demonstrated great potential in generating and managing code within complex codebases. In this paper, we introduce WebGen-Bench, a novel benchmark designed to measure an LLM-based agent's ability to create multi-file website codebases from scratch. It contains diverse instructions for website generation, created through the combined efforts of human annotators and GPT-4o. These instructions span three major categories and thirteen minor categories, encompassing nearly all important types of web applications.To assess the quality of the generated websites, we generate test cases targeting each functionality described in the instructions. These test cases are then manually filtered, refined, and organized to ensure accuracy, resulting in a total of 647 test cases. Each test case specifies an operation to be performed on the website and the expected outcome of the operation.To automate testing and improve reproducibility, we employ a powerful web-navigation agent to execute test cases on the generated websites and determine whether the observed responses align with the expected results.We evaluate three high-performance code-agent frameworks—Bolt.diy, OpenHands, and Aider—using multiple proprietary and open-source LLMs as engines. The best-performing combination, Bolt.diy powered by DeepSeek-R1, achieves only 27.8\% accuracy on the test cases, highlighting the challenging nature of our benchmark.Additionally, we construct WebGen-Instruct, a training set consisting of 6,667 website-generation instructions. Training Qwen2.5-Coder-32B-Instruct on Bolt.diy trajectories generated from a subset of the training set achieves an accuracy of 38.2\%, surpassing the performance of the best proprietary model.We release our data-generation, training, and testing code, along with both the datasets and model weights at https://github.com/mnluzimu/WebGen-Bench.
Zimu Lu, Yunqiao Yang 0002, Houxing Ren, Haotian Hou, Han Xiao 0010, Ke Wang 0036, Weikang Shi, Aojun Zhou, Mingjie Zhan, Hongsheng Li 0001
NeurIPS1
2025 UI-Genie: A Self-Improving Approach for Iteratively Boosting MLLM-based Mobile GUI Agents
abstract
In this paper, we introduce UI-Genie, a self-improving framework addressing two key challenges in GUI agents: verification of trajectory outcome is challenging and high-quality training data are not scalable. These challenges are addressed by a reward model and a self-improving pipeline, respectively. The reward model, UI-Genie-RM, features an image-text interleaved architecture that efficiently processes historical context and unifies action-level and task-level rewards. To support the training of UI-Genie-RM, we develop deliberately-designed data generation strategies including rule-based verification, controlled trajectory corruption, and hard negative mining. To address the second challenge, a self-improvement pipeline progressively expands solvable complex GUI tasks by enhancing both the agent and reward models through reward-guided exploration and outcome verification in dynamic environments. For training the model, we generate UI-Genie-RM-517k and UI-Genie-Agent-16k, establishing the first reward-specific dataset for GUI agents while demonstrating high-quality synthetic trajectory generation without manual annotation. Experimental results show that UI-Genie achieves state-of-the-art performance across multiple GUI agent benchmarks with three generations of data-model self-improvement. We open-source our complete framework implementation and generated datasets to facilitate further research in https://github.com/Euphoria16/UI-Genie.
Han Xiao 0010, Guozhi Wang, Yuxiang Chai, Zimu Lu, Weifeng Lin, Lue Fan, Liuyang Bian, Shuai Ren 0002, Yafei Wen, Xiaoxin Chen 0001, Aojun Zhou, Hongsheng Li 0001
NeurIPS4
2024 MathGenie: Generating Synthetic Data with Question Back-translation for Enhancing Mathematical Reasoning of LLMs
abstract
Zimu Lu, Aojun Zhou, Houxing Ren, Ke Wang, Weikang Shi, Junting Pan, Mingjie Zhan, Hongsheng Li. Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers). 2024.
Zimu Lu, Aojun Zhou, Houxing Ren, Ke Wang 0036, Weikang Shi, Junting Pan, Mingjie Zhan, Hongsheng Li 0001
ACL (1)1
2024 MathCoder: Seamless Code Integration in LLMs for Enhanced Mathematical Reasoning
abstract
The recently released GPT-4 Code Interpreter has demonstrated remarkable proficiency in solving challenging math problems, primarily attributed to its ability to seamlessly reason with natural language, generate code, execute code, and continue reasoning based on the execution output. In this paper, we present a method to fine-tune open-source language models, enabling them to use code for modeling and deriving math equations and, consequently, enhancing their mathematical reasoning abilities. We propose a method of generating novel and high-quality datasets with math problems and their code-based solutions, referred to as MathCodeInstruct. Each solution interleaves $\textit{natural language}$, $\textit{code}$, and $\textit{execution results}$. We also introduce a customized supervised fine-tuning and inference approach. This approach yields the MathCoder models, a family of models capable of generating code-based solutions for solving challenging math problems. Impressively, the MathCoder models achieve state-of-the-art scores among open-source LLMs on the MATH (45.2%) and GSM8K (83.9%) datasets, substantially outperforming other open-source alternatives. Notably, the MathCoder model not only surpasses ChatGPT-3.5 and PaLM-2 on GSM8K and MATH but also outperforms GPT-4 on the competition-level MATH dataset. The proposed dataset and models will be released upon acceptance.
Ke Wang 0036, Houxing Ren, Aojun Zhou, Zimu Lu, Sichun Luo, Weikang Shi, Renrui Zhang, Linqi Song, Mingjie Zhan, Hongsheng Li 0001
ICLR4
2024 Solving Challenging Math Word Problems Using GPT-4 Code Interpreter with Code-based Self-Verification
abstract
Recent progress in large language models (LLMs) like GPT-4 and PaLM-2 has brought significant advancements in addressing math reasoning problems. In particular, OpenAI's latest version of GPT-4, known as GPT-4 Code Interpreter, shows remarkable performance on challenging math datasets. In this paper, we explore the effect of code on enhancing LLMs' reasoning capability by introducing different constraints on the Code Usage Frequency of GPT-4 Code Interpreter. We found that its success can be largely attributed to its powerful skills in generating and executing code, evaluating the output of code execution, and rectifying its solution when receiving unreasonable outputs. Based on this insight, we propose a novel and effective prompting method, explicit $\underline{\text{c}}$ode-based $\underline{\text{s}}$elf-$\underline{\text{v}}$erification (CSV), to further boost the mathematical reasoning potential of GPT-4 Code Interpreter. This method employs a zero-shot prompt on GPT-4 Code Interpreter to encourage it to use code to self-verify its answers. In instances where the verification state registers as "False", the model shall automatically amend its solution, analogous to our approach of rectifying errors during a mathematics examination. Furthermore, we recognize that the states of the verification result indicate the confidence of a solution, which can improve the effectiveness of majority voting. With GPT-4 Code Interpreter and CSV, we achieve an impressive zero-shot accuracy on MATH dataset.
Aojun Zhou, Ke Wang 0036, Zimu Lu, Weikang Shi, Sichun Luo, Zipeng Qin, Shaoqing Lu, Anya Jia, Linqi Song, Mingjie Zhan, Hongsheng Li 0001
ICLR3
2024 Measuring Multimodal Mathematical Reasoning with MATH-Vision Dataset
abstract
Recent advancements in Large Multimodal Models (LMMs) have shown promising results in mathematical reasoning within visual contexts, with models exceeding human-level performance on existing benchmarks such as MathVista. However, we observe significant limitations in the diversity of questions and breadth of subjects covered by these benchmarks. To address this issue, we present the MATH-Vision (MATH-V) dataset, a meticulously curated collection of 3,040 high-quality mathematical problems with visual contexts sourced from real math competitions. Spanning 16 distinct mathematical disciplines and graded across 5 levels of difficulty, our dataset provides a comprehensive and diverse set of challenges for evaluating the mathematical reasoning abilities of LMMs. Through extensive experimentation, we unveil a notable performance gap between current LMMs and human performance on \datasetname, underscoring the imperative for further advancements in LMMs. Moreover, our detailed categorization allows for a thorough error analysis of LMMs, offering valuable insights to guide future research and development. The dataset is released at MathLLMs/MathVision
Ke Wang 0036, Junting Pan, Weikang Shi, Zimu Lu, Houxing Ren, Aojun Zhou, Mingjie Zhan, Hongsheng Li 0001
NeurIPS4
2024 Learning to Supervise Knowledge Retrieval Over a Tree Structure for Visual Question Answering
abstract
Knowledge-based visual question answering (KBVQA) aims to retrieve the external knowledge out of images to answer questions. However, current methods always introduce various irrelevant knowledge due to two drawbacks: (1) Synonymy issue. Existing methods heavily rely on words from questions or object labels in images to match knowledge from databases, which disregards the same word may hold multiple meanings within different contexts. (2) Knowledge uncertainty issue. Due to the absence of supervisory signals, recent methods can not determine which knowledge is applicable for answer inference, which can mislead to admit useless knowledge. To address these two problems, we propose to supervise the process of knowledge retrieval over a tree structure for KB-VQA task. For the synonymy issue, we construct a hierarchical knowledge tree to capture the subordination information between knowledge facts, mitigating the impact of synonyms on knowledge retrieval. For the knowledge uncertainty issue, we use the retrieval history as the ground truth to supervise the knowledge retrieval, which facilitates the QA model to form an explicit path of knowledge facts for answer understanding. Finally, we integrate the image, question, and retrieved knowledge into a variant of transformer to predict answers. Experimental results validate the effectiveness of the proposed method on KR-VQA, OK-VQA and VQA v2 datasets.
Ning Xu 0003, Zimu Lu, Hongshuo Tian, Rongbao Kang, Jinbo Cao, Yongdong Zhang 0001, Anan Liu
IEEE Trans. Multim.2
2024 Multi-stage reasoning on introspecting and revising bias for visual question answering
abstract
Visual Question Answering (VQA) is a task that involves predicting an answer to a question depending on the content of an image. However, recent VQA methods have relied more on language priors between the question and answer rather than the image content. To address this issue, many debiasing methods have been proposed to reduce language bias in model reasoning. However, the bias can be divided into two categories: good bias and bad bias. Good bias can benefit to the answer prediction, while the bad bias may associate the models with the unrelated information. Therefore, instead of excluding good and bad bias indiscriminately in existing debiasing methods, we proposed a bias discrimination module to distinguish them. Additionally, bad bias may reduce the model’s reliance on image content during answer reasoning and thus attend little on image features updating. To tackle this, we leverage Markov theory to construct a Markov field with image regions and question words as nodes. This helps with feature updating for both image regions and question words, thereby facilitating more accurate and comprehensive reasoning about both the image content and question. To verify the effectiveness of our network, we evaluate our network on VQA v2 and VQA cp v2 datasets and conduct extensive quantity and quality studies to verify the effectiveness of our proposed network. Experimental resu- lts show that our network achieves significant performance against the previous state-of-the-art methods.
Anan Liu, Zimu Lu, Ning Xu 0003, Min Liu 0008, Chenggang Yan 0001, Bolun Zheng, Yulong Duan, Xuanya Li
ACM Trans. Web2
2023 A comprehensive survey on deep-learning-based visual captioning
Bowen Xin, Ning Xu 0003, Yingchen Zhai, Zimu Lu, Jing Liu 0002, Weizhi Nie, Xuanya Li, Anan Liu
Multim. Syst.5
2021 Multi-type decision fusion network for visual Q&A
Anan Liu, Zimu Lu, Ning Xu 0003, Weizhi Nie, Wenhui Li 0001
Image Vis. Comput.2