August 4, 2026 PaletteID: Prototype-Composed Semantic Identifiers for Multimodal CTR Prediction PaletteID 提出基于原型的语义标识符（PID），通过 SQ-DPP 从多模态商品嵌入中选择原型调色板，保留连续语义信号，提升 CTR 预测的长尾泛化能力 ctr-prediction multimodal recommendation semantic-embedding prototype-learning dpp long-tail taobao