NIApr 20
Graph-based Hierarchical Deep Reinforcement Learning for Deliverable Block Propagation with Optimal Hybrid Cost in Web 3.0Shi Chen, Jinbo Wen, Jiawen Kang et al.
Web 3.0 is envisioned as a decentralized paradigm, where blockchain serves as a core technology for transparent and tamper-proof data management. Among various blockchain architectures, consortium blockchains have emerged as the preferred platform for enterprise-grade Web 3.0. For consortium blockchains, newly generated blocks are generally propagated to all consensus nodes for validation through the gossip protocol. However, gossip-based propagation may introduce substantial message redundancy and tail latency. Moreover, the consensus nodes exhibit heterogeneous availability patterns, and existing block propagation schemes often overlook such temporal constraints. Therefore, the joint optimization of propagation timeliness and delivery coverage remains an open problem. In this paper, we propose a deliverable block propagation optimization framework for consortium blockchain-enabled Web 3.0. We first propose a delivery-aware timeliness metric called Age of Validated Block (AoVB), which excludes block receptions occurring outside the availability window of each consensus node, thereby measuring only actionable synchronization latency. This metric is unified with the block arrival rate into a hybrid cost objective that balances timeliness against delivery. To solve this complex optimization problem, we propose a Graph-based Hierarchical Deep Reinforcement Learning (GHDRL) method, which comprises a graph isomorphism network-based assignment module and a graph attention network-based propagation module. The two modules are optimized jointly under a two-stage training strategy. Numerical results show that GHDRL consistently outperforms all compared schemes across network scales from 50 to 500 peers, achieving up to 19.2% lower hybrid cost than the best-performing neural baseline. Moreover, the model generalizes from 100-peer training instances to 500-peer deployments without retraining.
AIOct 24, 2025
MedAlign: A Synergistic Framework of Multimodal Preference Optimization and Federated Meta-Cognitive ReasoningSiyong Chen, Jinbo Wen, Jiawen Kang et al.
Recently, large models have shown significant potential for smart healthcare. However, the deployment of Large Vision-Language Models (LVLMs) for clinical services is currently hindered by three critical challenges: a tendency to hallucinate answers not grounded in visual evidence, the inefficiency of fixed-depth reasoning, and the difficulty of multi-institutional collaboration. To address these challenges, in this paper, we develop MedAlign, a novel framework to ensure visually accurate LVLM responses for Medical Visual Question Answering (Med-VQA). Specifically, we first propose a multimodal Direct Preference Optimization (mDPO) objective to explicitly align preference learning with visual context. We then design a Retrieval-Aware Mixture-of-Experts (RA-MoE) architecture that utilizes image and text similarity to route queries to a specialized and context-augmented LVLM (i.e., an expert), thereby mitigating hallucinations in LVLMs. To achieve adaptive reasoning and facilitate multi-institutional collaboration, we propose a federated governance mechanism, where the selected expert, fine-tuned on clinical datasets based on mDPO, locally performs iterative Chain-of-Thought (CoT) reasoning via the local meta-cognitive uncertainty estimator. Extensive experiments on three representative Med-VQA datasets demonstrate that MedAlign achieves state-of-the-art performance, outperforming strong retrieval-augmented baselines by up to $11.85\%$ in F1-score, and simultaneously reducing the average reasoning length by $51.60\%$ compared with fixed-depth CoT approaches.
CROct 20, 2025
ParaVul: A Parallel Large Language Model and Retrieval-Augmented Framework for Smart Contract Vulnerability DetectionTenghui Huang, Jinbo Wen, Jiawen Kang et al.
Smart contracts play a significant role in automating blockchain services. Nevertheless, vulnerabilities in smart contracts pose serious threats to blockchain security. Currently, traditional detection methods primarily rely on static analysis and formal verification, which can result in high false-positive rates and poor scalability. Large Language Models (LLMs) have recently made significant progress in smart contract vulnerability detection. However, they still face challenges such as high inference costs and substantial computational overhead. In this paper, we propose ParaVul, a parallel LLM and retrieval-augmented framework to improve the reliability and accuracy of smart contract vulnerability detection. Specifically, we first develop Sparse Low-Rank Adaptation (SLoRA) for LLM fine-tuning. SLoRA introduces sparsification by incorporating a sparse matrix into quantized LoRA-based LLMs, thereby reducing computational overhead and resource requirements while enhancing their ability to understand vulnerability-related issues. We then construct a vulnerability contract dataset and develop a hybrid Retrieval-Augmented Generation (RAG) system that integrates dense retrieval with Best Matching 25 (BM25), assisting in verifying the results generated by the LLM. Furthermore, we propose a meta-learning model to fuse the outputs of the RAG system and the LLM, thereby generating the final detection results. After completing vulnerability detection, we design chain-of-thought prompts to guide LLMs to generate comprehensive vulnerability detection reports. Simulation results demonstrate the superiority of ParaVul, especially in terms of F1 scores, achieving 0.9398 for single-label detection and 0.9330 for multi-label detection.