week5 LIS 2600 reading notes

1, wiki compression

Wiki make a comparison between lossless compression and lossy compression. In lossless compression, we do not lose data after compressing and the result is exactly identical to the original ones. But in lossy compression, we lose data in the process of compression. The author takes some examples to illustrate his point.

In digital libraries, it is important to figure out the methods of data compression in digital transfer and digital preservation. The preservation of master copies is vital to human heritage but this would take huge space to store them. We need to choose appropriate methods to preserve different materials.

2, Data compression basics

The author mainly talks about the lossless data compression methods including run-length encoding, the Lempel- Ziv compressor family, entropy coding and prediction and error coding. Then the author make comparisons among RLE, LZ and prediction.

Speaking about compressing English characters, how about another languages like Chinese characters? Do they use the same theory? But I cannot think out the way of compressing Chinese characters. Is there a ratio compression difference among difference language characters?

3, Edward A. Galloway, “Imaging Pittsburgh: Creating a shared gateway to digital image collections of the Pittsburgh region” First Monday 9:5 2004

This paper summarizes remarks made at Web–Wise 2004 Conference in Chicago.

http://firstmonday.org/htbin/cgiwrap/bin/ojs/index.php/fm/article/view/1141/1061

This is the right URL to the article.

The author talks about several challenges facing them. This is the common problems when two or more different corporations try to cooperate with each other, especially in various fields. I am interested in the metadata challenge. Now we have followed up many new metadatat standards such as Dublin Core, which is easier to handle that MARC. But according to this characteristic, two people may create two records except the required part of Dubline Core. How to deal with this problem? More and more metadata standards are created now, but we do not have a common standard like MARC in the past. How to realize the interoperability among these standards?

4, Paula L. Webb, YouTube and libraries: It could be a beautiful relationship C&RL News, June 2007 Vol. 68, No. 6 0

Available Link:

http://www.lita.org/ala/mgrps/divs/acrl/publications/crlnews/2007/jun/youtube.cfm

The URL that the instructor gave us is a dead link.

This is an interesting article. I partly agree with the author’s viewpoints. Libraries can use youtube to help develop their services and meet the needs of patrons. Libraries should catch up with the current fashion.

I logged on the homepage of computer history museum. (http://www.computerhistory.org/) They use youtube to collect and display their speeches and presentations. This is new and interesting. Libraries now are lack of videos to publicize themselves. Youtube is a good platform for libraries to put their services to more internet patrons.