May 2018
Intermediate to advanced
228 pages
4h 11m
Japanese
Content preview from Rによるテキストマイニング ―tidytextを活用したデータ分析と可視化の基礎
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■
149
8
章
ケーススタディ：
NASA
メタデータのマイニング
NASA
（
https://www.nasa.gov/
）がホスティングし、保守しているデータセットは
32,000
以上あります。これらのデータセットは、地球科学、宇宙工学、
NASA
自体
の運営など多岐にわたります。これらのデータセットのメタデータを使えば、デー
タセット相互の結び付きを理解できます。
メタデータとは何なのでしょうか。メタデータとは、ほかのデータにつ
いての情報を与えてくれるデータのことです。この場合、メタデータは、
膨大な
NASA
のデータセットに何が含まれているかを教えてくれるデー
タであり、データセット自体の中身は含みません。
メタデータには、データセットのタイトル、簡単な説明、そのデータセットに対
して責任を負う
NASA
の部署、人間がデータセットに付けたキーワードといったも
のが含まれます。
NASA
は、データを公開し、アクセス可能にすることに高い優先
順位を置いており、
NASA
が資金提供する研究には、自由にアクセスできるように
することを義務付けてさえいます（
https://www.nasa.gov/press-release/nasa-unveils-
new-public-web-portal-for-research-results
）。すべてのデータセットのメタデータは
JSO
N
形式で、自由にアクセスできます（
https://data.nasa.gov/data.json
）。
この章では、
NASA
メタデータを
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.