HAS International Seminar

Presenter: Yingfan Xu

Title: From Low-Quality Handheld Fundus Photos to Reliable Risk Signals: Multimodal Multi-Task Learning with Clinical Metadata

Abstract: Handheld fundus photography can scale diabetic eye screening, but real-world acquisition often yields blur, non-uniform illumination, motion artifacts, and occlusions that undermine image-only models. We develop a composite multimodal multi-task learning framework that integrates low-quality fundus photographs with routinely collected clinical and demographic variables to predict retinopathy severity, macular edema, and referral necessity. We benchmark strong unimodal baselines and representative fusion mechanisms, including feature concatenation, conditional modulation, learnable modality gating, and cross-attention. We further introduce an early-fusion module that models modality interactions through residual low-rank relational conditioning, generating complementary fusion experts and selecting them via task-wise mixture gates. For additional robustness and deployment flexibility, we ensemble logits from the multimodal model and two unimodal experts with either validation-selected weights or learned task-adaptive weighting, and tune operating thresholds on held-out data. Results indicate consistent improvements and clinically actionable referral decisions under degraded imaging conditions.

Presenter: Milad Asadpour

Title: From breakage to breakthrough: Contract mechanisms to improve vaccine vial quality

Abstract: Glass vials are widely preferred in pharmaceutical packaging due to their unique attributes, particularly their ability to protect the liquid contents from contamination by moisture, oxygen, and chemicals. Despite these advantages, glass vials have significant drawbacks that may hinder the efficient delivery of vaccines. The most critical issue is breakage, which can occur at various stages—from pre-filling to post-filling processes. Official reports indicate that vaccine vial breakage rates can average around 10% of total vials. Given the large-scale production of vaccines, even this seemingly modest percentage results in a substantial number of damaged vials, potentially disrupting supply chains. To address these challenges, vial suppliers must prioritize improving vial quality. Using a game-theoretical framework, we model the interaction between a single vial supplier and a single vaccine manufacturer. We formulate two types of contracts—profit-sharing, in which the manufacturer shares a percentage of profit with the supplier, and milestone payments, where the manufacturer provides an upfront payment followed by another payment upon successful project completion. We evaluate the effectiveness of these contracts in promoting innovation aimed at reducing vial breakage. We found that milestone contract can outperform profit-sharing in both innovation support and final price of vaccine.