Authors

Pengfei Zhang

Publications 5

Preprint Open access

Cancerous Backdoor Attack: Gradual Activation via Invisible Tokens and A Stage Controller

Backdoor Attacks on Large Language Models (LLMs) typically follow a trigger-response pattern, where satisfying a trigger condition activates a single terminal behavior. However, this single-point backdoor activation does not explore attacks in which malicious behavior develops gradually through multiple intermediate st …

Preprint Open access

Devils in Question Relay: Source-Conditioned Relay Steering to Mitigate Hallucinations in Audio-visual Large Language Models

Audio-visual large language models (AVLLMs) have made remarkable progress in multimodal understanding and reasoning through interactions among visual, auditory, and linguistic information. However, recent studies show that AVLLMs face a critical challenge: $\textbf{source-confused grounding hallucination}$, where cues …

Research article Open access

A weighted Stackelberg strategy approach for three pursuers against a superior evader using reinforcement learning

Ziyi Zhan, Yiqun Zhang, Pengfei Zhang · Journal of King Saud University: Computer and Information Sciences · 2025 · 10.1007/s44443-025-00176-2

Multi-player pursuit-evasion games under measurement noise are of great importance in aerospace and robotics. This paper investigates a differential game involving three cooperative pursuers and a single superior evader under system uncertainties. The payoff function is the terminal distance of the evader and its neare …

Research article Open access

Performance of Deep Transfer Learning for Detecting Abnormal Fundus Images

Yan Yu, Xiao Chen, XiangBing Zhu et al. · Journal of Current Ophthalmology · 2020 · 10.4103/joco.joco_123_20

Purpose: To develop and validate a deep transfer learning (DTL) algorithm for detecting abnormalities in fundus images from non-mydriatic fundus photography examinations. Methods: A total of 1295 fundus images were collected to develop and validate a DTL algorithm for detecting abnormal fundus images. After removing 36 …

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