-<p>At work with the University of Oslo, we have several hundred computers
-in our computing center. This give us a challenge in tracking the
-location and cabling of the computers, when they are added, moved and
-removed. Some times the location register is not updated when a
-computer is inserted or moved and we then have to search the room for
-the "missing" computer.</p>
-
-<p>In the last issue of Linux Journal, I came across a project
-<a href="http://www.libdmtx.org/">libdmtx</a> to write and read bar
-code blocks as defined in the
-<a href="http://en.wikipedia.org/wiki/Data_Matrix">The Data Matrix
-Standard</a>. This is bar codes that can be read with a normal
-digital camera, for example that on a cell phone, and several such bar
-codes can be read by libdmtx from one picture. The bar code standard
-allow up to 2 KiB to be written in the tag. There is another project
-with <a href="http://www.terryburton.co.uk/barcodewriter/">a bar code
-writer written in postscript</a> capable of creating such bar codes,
-but this was the first time I found a tool to read these bar
-codes.</p>
-
-<p>It occurred to me that this could be used to tag and track the
-machines in our computing center. If both racks and computers are
-tagged this way, we can use a picture of the rack and all its
-computers to detect the rack location of any computer in that rack.
-If we do this regularly for the entire room, we will find all
-locations, and can detect movements and removals.</p>
-
-<p>I decided to test if this would work in practice, and picked a
-random rack and tagged all the machines with their names. Next, I
-took pictures with my digital camera, and gave the dmtxread program
-these JPEG pictures to see how many tags it could read. This worked
-fairly well. If the pictures was well focused and not taken from the
-side, all tags in the image could be read. Because of limited space
-between the racks, I was unable to get a good picture of the entire
-rack, but could without problem read all tags from a picture covering
-about half the rack. I had to limit the search time used by dmtxread
-to 60000 ms to make sure it terminated in a reasonable time frame.</p>
-
-<p>My conclusion is that this could work, and we should probably look
-at adjusting our computer tagging procedures to use bar codes for
-easier automatic tracking of computers.</p>
-</description>
- </item>
-
- <item>
- <title>Kart over overvåkningskamera i Norge</title>
- <link>Kart_over_overv__kningskamera_i_Norge.html</link>
- <guid isPermaLink="true">Kart_over_overv__kningskamera_i_Norge.html</guid>
- <pubDate>Sun, 15 Feb 2009 22:30:00 +0100</pubDate>
- <description>
-<p>I regi av
-<a href="http://www.personvern.no/">personvernforeningen</a> har jeg
-startet på
-<a href="http://personvern.no/wiki/index.php/Kameraovervåkning">et
-kart over overvåkningskamera i Norge</a>. Bakgrunnen er at det etter
-min mening bærer galt avsted med den massive overvåkningen som
-finner sted i Norge i dag, og at flere og flere overvåkningskamera
-gjør det vanskeligere og vanskeligere å gå igjennom livet uten at
-små og store brødre trenger inn i ens private sfære. Datatilsynet
-har et register over kameraovervåkning, men det viser seg å være
-ubrukelig både til å finne ut hvor det er kamera plassert, og til å
-sjekke om et kamera en kommer over er registrert. Dette nye kartet
-fikser en av disse manglene, men det vil fortsatt være umulig å vite
-om et kamera er registrert etter lovens krav eller ikke. Pr. nå er
-22 kamera i Oslo registrert, og det trengs flere til å registrere
-alle. Informasjonen registreres direkte inn i <a
-href="http://www.openstreetmap.org/">OpenStreetmap</a>, sa hentes det
-automatisk over i spesialkartet.</p>