{
  "annotation_id": "96847031-662f-4b76-9d95-dccb6336c061",
  "date_created": "2026-03-02T18:00:57.286000Z",
  "date_modified": "2026-03-02T18:00:57.286000Z",
  "file_hash": "0dd34ac78087cccf43308c5e6a002cc7aa73a8a6ae3f1193b313877c267584e9",
  "private": false,
  "record": {
    "abstract": "A surrogate data analysis is presented, which is based on the fluctuations of\nthe ``entropy\u0027\u0027 $S$ defined in the natural time-domain [Phys. Rev. E {\\bf 68},\n031106, 2003]. This entropy is not a static one as, for example, the Shannon\nentropy. The analysis is applied to three types of time-series, i.e., seismic\nelectric signals, ``artificial\u0027\u0027 noises and electrocardiograms, and\n``recognizes\u0027\u0027 the non-Markovianity in all these signals. Furthermore, it\ndifferentiates the electrocardiograms of healthy humans from those of the\nsudden cardiac death ones. If $\\delta S$ and $\\delta S_{shuf}$ denote the\nstandard deviation when calculating the entropy by means of a time-window\nsweeping through the original data and the ``shuffled\u0027\u0027 (randomized) data,\nrespectively, it seems that the ratio $\\delta S_{shuf}/\\delta S$ plays a\nkey-role. The physical meaning of $\\delta S_{shuf}$ is investigated.",
    "arxiv_id": "physics/0501117",
    "authors": [
      "P. A. Varotsos",
      "N. V. Sarlis",
      "E. S. Skordas",
      "M. S. Lazaridou"
    ],
    "categories": [
      "physics.data-an",
      "physics.bio-ph"
    ],
    "doi": "10.1103/PhysRevE.70.011106",
    "journal_ref": "Phys. Rev. E 70, 011106 (2004)",
    "title": "Entropy in the natural time-domain",
    "url": "https://arxiv.org/abs/physics/0501117"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "b7fb7d4c-6dad-45cb-a3ec-dfb655275d4e",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}