arXiv subjects

Van-Vi Vo

Publications and source records attributed to Van-Vi Vo.

4 recordsLinked to original sources

arXiv2026

Response-Aware Multimodal Learning for Post-Treatment Visual Acuity Forecasting

Long-term visual acuity (VA) outcomes after anti-VEGF therapy are central to patient counseling, expectation setting, and follow-up planning in diabetic macular edema (DME). However, in clinical practice, physicians must often estimate long-term visual trajectories based only on early post-treatment findings, making reliable prognostication difficult. Although prior OCT-based learning approaches have largely focused on short-term response or single-endpoint prediction, modeling VA trajectories across multiple future time points from early longitudinal observations remains insufficiently explored. In this study, we assembled a real-world cohort of 188 anti-VEGF--treated DME patients with paired baseline and month-1 OCT scans, along with tabular OCT-derived biomarkers and non-imaging clinical variables. Using only these early data, we formulate a multi-horizon VA forecasting problem aimed at predicting visual outcomes at 3, 6, 12, 18, and 24 months, reflecting clinically meaningful follow-up intervals. We propose \textbf{ReVA}, a response-aware multimodal framework that integrates structural features from baseline and month-1 OCT with the tabular variables to capture baseline disease status and early treatment response. ReVA uses spatial attention to preserve localized prognostic imaging features and a dependency-aware tabular encoder to model interactions among clinical variables. These multimodal representations are fused to predict patient-specific long-term visual acuity trajectories. The proposed framework achieves MAE $=0.1246$, RMSE $=0.1621$, and $R^2=0.6064$ for 24-month VA prediction, with consistent performance across all forecast horizons. Our findings show that incorporating early treatment-response signals enables clinically meaningful long-term visual acuity forecasting, supporting data-driven decision support for routine anti-VEGF management.

cs.CV↗

arXiv2025

Distributed Q-learning-based Shortest-Path Tree Construction in IoT Sensor Networks

Efficient routing in IoT sensor networks is critical for minimizing energy consumption and latency. Traditional centralized algorithms, such as Dijkstra's, are computationally intensive and ill-suited for dynamic, distributed IoT environments. We propose a novel distributed Q-learning framework for constructing shortest-path trees (SPTs), enabling sensor nodes to independently learn optimal next-hop decisions using only local information. States are defined based on node positions and routing history, with a reward function that incentivizes progression toward the sink while penalizing inefficient paths. Trained on diverse network topologies, the framework generalizes effectively to unseen networks. Simulations across 100 to 500 nodes demonstrate near-optimal routing accuracy (over 99% for networks with more than 300 nodes), with minor deviations (1-2 extra hops) in smaller networks having negligible impact on performance. Compared to centralized and flooding-based methods, our approach reduces communication overhead, adapts to topology changes, and enhances scalability and energy efficiency. This work underscores the potential of Q-learning for autonomous, robust routing in resource-constrained IoT networks, offering a scalable alternative to traditional protocols.

cs.DC↗

arXiv2025

Q-Learning-Based Time-Critical Data Aggregation Scheduling in IoT

Time-critical data aggregation in Internet of Things (IoT) networks demands efficient, collision-free scheduling to minimize latency for applications like smart cities and industrial automation. Traditional heuristic methods, with two-phase tree construction and scheduling, often suffer from high computational overhead and suboptimal delays due to their static nature. To address this, we propose a novel Q-learning framework that unifies aggregation tree construction and scheduling, modeling the process as a Markov Decision Process (MDP) with hashed states for scalability. By leveraging a reward function that promotes large, interference-free batch transmissions, our approach dynamically learns optimal scheduling policies. Simulations on static networks with up to 300 nodes demonstrate up to 10.87% lower latency compared to a state-of-the-art heuristic algorithm, highlighting its robustness for delay-sensitive IoT applications. This framework enables timely insights in IoT environments, paving the way for scalable, low-latency data aggregation.

cs.NI↗

arXiv2023

Minimal Sleep Delay Driven Aggregation Tree Construction in IoT Sensor Networks

Data aggregation is a fundamental technique in wireless sensor networks (WSNs) in which sensory data collected by intermediate nodes is merged by in-network computation using maximum, average, or sum functions. Because sensors run on batteries, energy conservation is a critical issue. Duty cycle is a well-known energy-saving mechanism in WSNs, but it causes data aggregation latency to increase. As a result, the use of multichannel technology allows more sensor nodes to send data simultaneously, reducing data aggregation latency. We investigate the minimum latency aggregation scheduling problem in multi-channel duty-cycled IoT sensor networks in this paper. We propose a scheduling scheme that first constructs an aggregation tree based on sensor node sleep delay, then improves parallel transmissions by scheduling all eligible nodes in the constructed aggregation tree to enhance data aggregation. Based on extensive simulation experiments, our proposed approach lowers the aggregation delay by at most 61% compared to a novel approach.

cs.NI↗