{
  "id": 4001,
  "title": "Clarification: x.PSD.1",
  "url": "/competitions/predicting-parkinson-s-disease-progression-with-smartphone-data/discussion/4001",
  "author_name": "",
  "post_date": "2013-03-10T07:11:48.390Z",
  "votes": null,
  "comment_count": 1,
  "views": 1683,
  "content": "<p>My team and I are wondering if someone can clarify what exactly the x.PSD.1, x.PSD.3, x.PSD.6, and x.PSD.10 variables are capturing? &nbsp;How is &quot;motion energy&quot; defined? What do the descriptions of the ranges, low, low-mid, mid-high, high, refer to? Why are\r\n these variables labeled PSD?</p>\r\n<p>Thanks for the help!</p>",
  "messages": [
    {
      "id": "21209",
      "postDate": "03/10/2013 07:11:48",
      "content": "<p>My team and I are wondering if someone can clarify what exactly the x.PSD.1, x.PSD.3, x.PSD.6, and x.PSD.10 variables are capturing? &nbsp;How is &quot;motion energy&quot; defined? What do the descriptions of the ranges, low, low-mid, mid-high, high, refer to? Why are\r\n these variables labeled PSD?</p>\r\n<p>Thanks for the help!</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "21226",
      "postDate": "03/11/2013 14:05:38",
      "content": "<p>Here are some more details that I hope are helpful.&nbsp; PSD refers to 'power spectral density'. The numbers refer to the PSD<br>\r\n(upper edge of) frequency bands.&nbsp; The data is generally dimensionless, so there are no specific units other than this that make much sense in this context.</p>\r\n<p>Hope that helps!</p>",
      "rawMarkdown": "",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 21226,
      "author_name": "dvannoni",
      "author_url": "",
      "post_date": "03/11/2013 14:05:38",
      "content": "<p>Here are some more details that I hope are helpful.&nbsp; PSD refers to 'power spectral density'. The numbers refer to the PSD<br>\r\n(upper edge of) frequency bands.&nbsp; The data is generally dimensionless, so there are no specific units other than this that make much sense in this context.</p>\r\n<p>Hope that helps!</p>",
      "votes": null,
      "replies": []
    }
  ],
  "raw_markdown_by_id": {
    "21209": "",
    "21226": ""
  },
  "source": "meta"
}