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Yongfeng Zhang

33 accepted papers

2025

ADO: Automatic Data Optimization for Inputs in LLM Prompts

ACL 2025finding

This study explores a novel approach to enhance the performance of Large Language Models (LLMs) through the optimization of input data within prompts. While previous research has primarily focused on refining instruction components and augmenting input data with in-context examples, our work investi…

2025

Agent Security Bench (ASB): Formalizing and Benchmarking Attacks and Defenses in LLM-based Agents

ICLR 2025poster

Although LLM-based agents, powered by Large Language Models (LLMs), can use external tools and memory mechanisms to solve complex real-world tasks, they may also introduce critical security vulnerabilities. However, the existing literature does not comprehensively evaluate attacks and defenses again…

2025

Cerebrum (AIOS SDK): A Platform for Agent Development, Deployment, Distribution, and Discovery

NAACL 2025system demonstrations

Autonomous LLM-based agents have emerged as a powerful paradigm for complex task execution, yet the field lacks standardized tools for development, deployment, and distribution. We present Cerebrum, an open-source platform that addresses this gap through three key components: (1) a comprehensive SDK…

2025

Disentangling Logic: The Role of Context in Large Language Model Reasoning Capabilities

ACL 2025finding

This study intends to systematically disentangle pure logic reasoning and text understanding by investigating the contrast across abstract and contextualized logical problems from a comprehensive set of domains. We explore whether LLMs demonstrate genuine reasoning capabilities across various domain…

2025

Disentangling Memory and Reasoning Ability in Large Language Models

ACL 2025long

Large Language Models (LLMs) have demonstrated strong performance in handling complex tasks that require both extensive knowledge and reasoning abilities. However, the existing LLM inference pipeline operates as an opaque process without explicit separation between knowledge retrieval and reasoning…

2025

EmojiPrompt: Generative Prompt Obfuscation for Privacy-Preserving Communication with Cloud-based LLMs

NAACL 2025long

Cloud-based Large Language Models (LLMs) such as ChatGPT have become increasingly integral to daily operations. Nevertheless, they also introduce privacy concerns: firstly, numerous studies underscore the risks to user privacy posed by jailbreaking cloud-based LLMs; secondly, the LLM service provide…

2025

Exploring Concept Depth: How Large Language Models Acquire Knowledge and Concept at Different Layers?

COLING 2025main

Large language models (LLMs) have shown remarkable performances across a wide range of tasks. However, the mechanisms by which these models encode tasks of varying complexities remain poorly understood. In this paper, we explore the hypothesis that LLMs process concepts of varying complexities in di…

2025

From Commands to Prompts: LLM-based Semantic File System for AIOS

ICLR 2025poster

Large language models (LLMs) have demonstrated significant potential in the development of intelligent LLM-based agents. However, when users use these agent applications to perform file operations, their interaction with the file system still remains the traditional paradigm: reliant on manual navig…

2025

Interactive Speculative Planning: Enhance Agent Efficiency through Co-design of System and User Interface

ICLR 2025poster

Agents, as user-centric tools, are increasingly deployed for human task delegation, assisting with a broad spectrum of requests by generating thoughts, engaging with user proxies, and producing action plans. However, agents based on large language models often face substantial planning latency due t…

Cited by 3SourcePDFScholar
2025

Invisible Prompts, Visible Threats: Malicious Font Injection in External Resources for Large Language Models

EMNLP 2025

Large Language Models (LLMs) are increasingly equipped with capabilities of real-time web search and integrated with protocols like the Model Context Protocol (MCP). This extension could introduce new security vulnerabilities. We present a systematic investigation of LLM vulnerabilities to hidden ad

2025

Massive Values in Self-Attention Modules are the Key to Contextual Knowledge Understanding

ICML 2025poster

Large language models (LLMs) have achieved remarkable success in contextual knowledge understanding. In this paper, we show for the first time that these concentrated massive values consistently emerge in specific regions of attention queries (Q) and keys (K) while not having such patterns in values…

2025

SAE-SSV: Supervised Steering in Sparse Representation Spaces for Reliable Control of Language Models

EMNLP 2025

Large language models (LLMs) have demonstrated impressive capabilities in natural language understanding and generation, but controlling their behavior reliably remains challenging, especially in open-ended generation settings. This paper introduces a novel supervised steering approach that operates

2025

SLMRec: Distilling Large Language Models into Small for Sequential Recommendation

ICLR 2025poster

Sequential Recommendation (SR) task involves predicting the next item a user is likely to interact with, given their past interactions. The SR models examine the sequence of a user's actions to discern more complex behavioral patterns and temporal dynamics. Recent research demonstrates the great i…

2025

Visual Agents as Fast and Slow Thinkers

ICLR 2025poster

Achieving human-level intelligence requires refining cognitive distinctions between \textit{System 1} and \textit{System 2} thinking. While contemporary AI, driven by large language models, demonstrates human-like traits, it falls short of genuine cognition. Transitioning from structured benchmarks…

2025

When Backdoors Speak: Understanding LLM Backdoor Attacks Through Model-Generated Explanations

ACL 2025long

Large Language Models (LLMs) are known to be vulnerable to backdoor attacks, where triggers embedded in poisoned samples can maliciously alter LLMs’ behaviors. In this paper, we move beyond attacking LLMs and instead examine backdoor attacks through the novel lens of natural language explanations. S…

Cited by 0SourcePDFScholar
2025

iAgent: LLM Agent as a Shield between User and Recommender Systems

ACL 2025finding

Traditional recommender systems usually take the user-platform paradigm, where users are directly exposed under the control of the platform’s recommendation algorithms. However, the defect of recommendation algorithms may put users in very vulnerable positions under this paradigm. First, many sophis…

2024

BattleAgent: Multi-modal Dynamic Emulation on Historical Battles to Complement Historical Analysis

EMNLP 2024system demonstrations

This paper presents BattleAgent, a detailed emulation demonstration system that combines the Large Vision-Language Model (VLM) and Multi-Agent System (MAS). This novel system aims to emulate complex dynamic interactions among multiple agents, as well as between agents and their environments, over a…

2024

Large Language Models for Generative Recommendation: A Survey and Visionary Discussions

COLING 2024main

Large language models (LLM) not only have revolutionized the field of natural language processing (NLP) but also have the potential to reshape many other fields, e.g., recommender systems (RS). However, most of the related work treats an LLM as a component of the conventional recommendation pipeline…

Cited by 105SourcePDFScholar
2024

NPHardEval: Dynamic Benchmark on Reasoning Ability of Large Language Models via Complexity Classes

ACL 2024long

Complex reasoning ability is one of the most important features of Large Language Models (LLMs). Numerous benchmarks have been established to assess the reasoning abilities of LLMs. However, they are inadequate in offering a rigorous evaluation and prone to the risk of overfitting, as these publicly…

2024

The Impact of Reasoning Step Length on Large Language Models

ACL 2024findings

Chain of Thought (CoT) is significant in improving the reasoning abilities of large language models (LLMs). However, the correlation between the effectiveness of CoT and the length of reasoning steps in prompts remains largely unknown. To shed light on this, we have conducted several empirical exper…

Cited by 85SourcePDFScholar
2024

TrustAgent: Towards Safe and Trustworthy LLM-based Agents

EMNLP 2024finding

The rise of LLM-based agents shows great potential to revolutionize task planning, capturing significant attention. Given that these agents will be integrated into high-stake domains, ensuring their reliability and safety is crucial. This paper presents an Agent-Constitution-based agent framework, T…

2023

HiCLIP: Contrastive Language-Image Pretraining with Hierarchy-aware Attention

ICLR 2023poster

The success of large-scale contrastive vision-language pretraining (CLIP) has benefited both visual recognition and multimodal content understanding. The concise design brings CLIP the advantage in inference efficiency against other vision-language models with heavier cross-attention fusion layers,…

2023

VIP5: Towards Multimodal Foundation Models for Recommendation

EMNLP 2023long findings

Computer Vision (CV), Natural Language Processing (NLP), and Recommender Systems (RecSys) are three prominent AI applications that have traditionally developed independently, resulting in disparate modeling and engineering methodologies. This has impeded the ability for these fields to directly bene…

Cited by 0SourcecodeScholar
2022

Data-Efficient Concept Extraction from Pre-trained Language Models for Commonsense Explanation Generation

EMNLP 2022finding

Predicting the key explanation concept is essential for generating commonsense explanations. This paper introduces a method to predict the concept from pre-trained language models for commonsense explanation generation. Our experiment found that adopting a language model as the concept extractor and…

Cited by 7SourcePDFScholar
2022

Improving Personalized Explanation Generation through Visualization

ACL 2022long

In modern recommender systems, there are usually comments or reviews from users that justify their ratings for different items. Trained on such textual corpus, explainable recommendation models learn to discover user interests and generate personalized explanations. Though able to provide plausible…

Cited by 37SourcePDFScholar
2022

System 1 + System 2 = Better World: Neural-Symbolic Chain of Logic Reasoning

EMNLP 2022finding

Logical reasoning is a challenge for many current NLP neural network models since it requires more than the ability of learning informative representations from data. Inspired by the Dual Process Theory in cognitive science — which proposes that human cognition process involves two stages: an intuit…

2021

Dynamic Graph Representation Learning for Video Dialog via Multi-Modal Shuffled Transformers

AAAI 2021technical

Given an input video, its associated audio, and a brief caption, the audio-visual scene aware dialog (AVSD) task requires an agent to indulge in a question-answer dialog with a human about the audio-visual content. This task thus poses a challenging multi-modal representation learning and reasoning…

Cited by 50SourcePDFScholar
2021

Faithfully Explainable Recommendation via Neural Logic Reasoning

NAACL 2021long

Knowledge graphs (KG) have become increasingly important to endow modern recommender systems with the ability to generate traceable reasoning paths to explain the recommendation process. However, prior research rarely considers the faithfulness of the derived explanations to justify the decision-mak…

2020

A Representation Learning Approach to Animal Biodiversity Conservation

COLING 2020main

Generating knowledge from natural language data has aided in solving many artificial intelligence problems. Vector representations of words have been the driving force behind the majority of natural language processing tasks. This paper develops a novel approach for predicting the conservation statu…

2020

HID: Hierarchical Multiscale Representation Learning for Information Diffusion

IJCAI 2020poster

Multiscale modeling has yielded immense success on various machine learning tasks. However, it has not been properly explored for the prominent task of information diffusion, which aims to understand how information propagates along users in online social networks. For a specific user, whether and w…