Back in March Google announced that this weekend is the end of Google Reader, the service many bloggers and journalists used to use to read online content via RSS. This wasn't the first service Google killed, but because the people who used the service write for the Web, the announcement sparked a lively discussion. Because many people believe that commercial content platforms and storage services will preserve digital content for the long term, the discussion below the fold should be of interest here.
Thursday, June 27, 2013
Tuesday, June 25, 2013
The Big Deal
Andrew Odlyzko has a fascinating paper with a rather long title, Open Access, library and publisher competition, and the evolution of general commerce (PDF). He describes how the relationship between the libraries and the publishers in the market for academic journals has evolved to transfer resources from libraries to the publishers, and how a similar strategy might play out in many, more general markets. Below the fold I discuss some of the details, but you should read the whole thing.
Friday, June 21, 2013
Petabyte DVD?
Simon Sharwood at The Register points to a paper in Nature Communications (and a more readable explanation) by a team from Swinburne University of Technology that may eventually allow for a petabyte on a single DVD platter.
They have found a way around Abbe's limit, which restricts the width of a light beam to be more than half its wavelength. They use two beams, each of which on its own is more than half a wavelength wide. One is round, and one is donut shaped and they overlap. Then, as with normal DVDs, they use a medium which contains a dye activated by the round beam. The secret is that the donut-shaped beam prevents the dye being activated. So the size of the written spot on the medium is the size of the hole in the donut, in their case only 9nm across. With 9nm dots it is in theory possible to get a petabyte on a DVD.
However, as the Library of Congress and others have observed, dye-based DVD media typically have a short data retention life even at current feature sizes, much larger than 9nm. So although the capacity of the DVDs the team envisages is impressive, they aren't likely to be much use for digital preservation.
They have found a way around Abbe's limit, which restricts the width of a light beam to be more than half its wavelength. They use two beams, each of which on its own is more than half a wavelength wide. One is round, and one is donut shaped and they overlap. Then, as with normal DVDs, they use a medium which contains a dye activated by the round beam. The secret is that the donut-shaped beam prevents the dye being activated. So the size of the written spot on the medium is the size of the hole in the donut, in their case only 9nm across. With 9nm dots it is in theory possible to get a petabyte on a DVD.
However, as the Library of Congress and others have observed, dye-based DVD media typically have a short data retention life even at current feature sizes, much larger than 9nm. So although the capacity of the DVDs the team envisages is impressive, they aren't likely to be much use for digital preservation.
Tuesday, June 18, 2013
Not trusting cloud storage
I'm trying to work through my stack of half-completed blog posts. Some months ago Jane Mandelbaum at the Library of Congress pointed me to Towards self-repairing replication-based storage systems using untrusted clouds by Bo Chen and Reza Curtmola. It received an “Outstanding Paper Award” at CODASPY 2013. Let me start by saying that the technique they describe is interesting and, as far as I can tell, represents an advance in some important respects on earlier work.
However, it is also an example, if not a severe one, of the problem I discussed in my post Journals Considered Harmful of authors hyping their work in order to be published in a higher-profile forum, and reviewers failing to catch this exaggeration. Follow me below the fold for the details.
However, it is also an example, if not a severe one, of the problem I discussed in my post Journals Considered Harmful of authors hyping their work in order to be published in a higher-profile forum, and reviewers failing to catch this exaggeration. Follow me below the fold for the details.
Saturday, June 15, 2013
Cliff Lynch
Two quick plugs. The first for Mike Ashenfelder's profile of Cliff Lynch in the Library of Congress' Digital Preservation Pioneer series. Cliff has helped the LOCKSS Program in too many ways to count. Personally, I'm particularly grateful for his occasional invitations to speak to his class at UC Berkeley's School of Information. They have provided an essential spur to get me to pull my thoughts together in several important areas.
The second is Cliff's article on e-books for American Libraries recent e-book supplement. There is a lot to digest in it. I hope to return to some aspects in a later post, but his conclusion succinctly describes the threat to libraries:
The second is Cliff's article on e-books for American Libraries recent e-book supplement. There is a lot to digest in it. I hope to return to some aspects in a later post, but his conclusion succinctly describes the threat to libraries:
If we have not come to reasonable terms about e-books both the access and preservation functions of our libraries will be gravely threatened, and as a society, we will face a profound public policy problem. It is in every-one's interest, I believe, to avoid this crisis.
Thursday, June 13, 2013
Brief talk at ElPub 2013
I was on the panel entitled Setting Research Data Free: Problems and Solutions at the ElPub 2013 conference. Below the fold is the text of my introductory remarks with links to the sources.
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