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    "story_id": "mp-2026-08-29-010",
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    "headline": "The Robot Planned Five Steps Into the Crowd",
    "slug": "the-robot-planned-five-steps-into-the-crowd",
    "dek": "A diffusion policy generates short action chunks, then executes them in a receding horizon for dense crowd navigation.",
    "summary": "A diffusion policy generates short action chunks, then executes them in a receding horizon for dense crowd navigation.",
    "body_text": "PDPO combines offline demonstrations with online PPO and treats denoising as an internal decision process. The authors report better success than tested baselines and find that action chunks matter especially when benchmark boundaries count as collisions. That boundary change closes an artifact that otherwise let agents escape the valid domain instead of navigating through it.",
    "why_it_matters": "A diffusion policy generates short action chunks, then executes them in a receding horizon for dense crowd navigation.",
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    "importance": 7,
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    "first_published_at": "2026-08-29T09:00:00.000-04:00",
    "modified_at": "2026-08-29T09:00:00.000-04:00",
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    "tags": [
      "crowd navigation",
      "diffusion policies",
      "robotics"
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    "image_url": null,
    "corrections": []
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  "sources": [
    {
      "source_id": "source-2026-08-29-010",
      "title": "arXiv preprint 2608.27158",
      "publisher": "arXiv",
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      "published_at": "2026-08-27T10:10:39.000-04:00",
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  "publisher": {
    "name": "The Machine Press",
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    "description": "A daily newspaper for the age of artificial intelligence."
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  "cite_this_report": {
    "title": "The Robot Planned Five Steps Into the Crowd",
    "publisher": "The Machine Press",
    "published_at": "2026-08-29T09:00:00.000-04:00",
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