Yiming Xu https://ym-xu.github.io/ Recent content on Yiming Xu Hugo en Mon, 01 Jun 2026 00:00:00 +0000 Hierarchical Planner https://ym-xu.github.io/projects/hierarchical-planner/ Wed, 01 Jan 2025 00:00:00 +0000 https://ym-xu.github.io/projects/hierarchical-planner/ A navigation-first planner that walks a document’s hierarchy instead of flat top-k retrieval, using layered embeddings as routing hints. E-commerce AI Agent https://ym-xu.github.io/projects/ecommerce-agent/ Mon, 01 Jan 2024 00:00:00 +0000 https://ym-xu.github.io/projects/ecommerce-agent/ Flagship conversational shopping agent. Led development end-to-end; the project went on to raise close to USD 7M in funding. Multimodal RAG https://ym-xu.github.io/projects/multimodal-rag/ Sun, 01 Jan 2023 00:00:00 +0000 https://ym-xu.github.io/projects/multimodal-rag/ Master’s thesis on retrieval-augmented generation across text and image, supervised by Benno Kruit and Jan-Christoph Kalo. Strategic Navigation or Stochastic Search? How Agents and Humans Reason Over Document Collections https://ym-xu.github.io/publications/icml-madqa/ Mon, 01 Jun 2026 00:00:00 +0000 https://ym-xu.github.io/publications/icml-madqa/ MADQA — a multimodal agentic document-QA benchmark that scores full search trajectories, not just answers, and shows agents match human accuracy only by working ~5× harder. AdaNav: Query-Adaptive Multi-Granularity Navigation for Long Document Understanding https://ym-xu.github.io/publications/icdar-adanav/ Wed, 01 Apr 2026 00:00:00 +0000 https://ym-xu.github.io/publications/icdar-adanav/ AdaNav builds a multimodal document tree and navigates it at query-adaptive granularity — no embedding retriever — beating open-source VLM agent systems by over 5% on MMLongBench-Doc while reading fewer pages. Planner design https://ym-xu.github.io/posts/2025/10/planner-design/ Tue, 07 Oct 2025 00:00:00 +0000 https://ym-xu.github.io/posts/2025/10/planner-design/ Hierarchical + leaf embeddings for navigation, not naive top-k retrieval. Context engineering https://ym-xu.github.io/posts/2025/09/context-engineering/ Sun, 21 Sep 2025 00:00:00 +0000 https://ym-xu.github.io/posts/2025/09/context-engineering/ Notes on shaping the context window as a first-class design surface. DocLens https://ym-xu.github.io/posts/2025/08/doclens/ Thu, 14 Aug 2025 00:00:00 +0000 https://ym-xu.github.io/posts/2025/08/doclens/ A layout-aware observer for structured document understanding. Reading list https://ym-xu.github.io/posts/2025/07/reading-list/ Wed, 02 Jul 2025 00:00:00 +0000 https://ym-xu.github.io/posts/2025/07/reading-list/ A running list of papers on multimodal retrieval and document AI. Retrieval-based Question Answering with Passage Expansion Using a Knowledge Graph https://ym-xu.github.io/publications/lrec-coling-2024-kg-qa/ Wed, 01 May 2024 00:00:00 +0000 https://ym-xu.github.io/publications/lrec-coling-2024-kg-qa/ A multimodal retriever that combines knowledge-graph entity features with dense text retrieval, improving open-domain QA precision on rare, entity-centric questions where dense retrievers fall short. Fine-grained label learning via siamese network for cross-modal information retrieval https://ym-xu.github.io/publications/iccs-fglab/ Sat, 08 Jun 2019 00:00:00 +0000 https://ym-xu.github.io/publications/iccs-fglab/ Fine-grained labels capture the “hardness” of text–image pairs; a siamese network and a weighted pairwise loss exploit them to improve cross-modal retrieval on three benchmarks.