Technical Information
The Digital South Asia Library (DSAL) is committed to implementing the most current international standards and technologies for the presentation and preservation of digital resources.
Standards & Metadata Software & Technology Archiving & Preservation Web Accessibility
Standards & Metadata
Unicode
For the display of non-roman scripts, DSAL uses Unicode. Because Unicode establishes unique values for language symbols, Unicode can be used across a variety of computer operating systems and software applications. Given the diversity of languages in South Asia and the global audience envisioned for DSAL, the use of Unicode for material presented on the Web site is an imperative.

The ISCII character encoding was developed and adopted by the Government of India and is widely used in South Asia for languages written in the various scripts derived from the Brahmi script. Indic languages written in Perso-Arabic script can not be encoded with ISCII. For the purposes of DSAL, ISCII files are translated into Unicode for display on the Web. The translation from ISCII to Unicode has been made simpler by the participation of the Government of India in the Unicode consortium.
Dublin Core
The technical term metadata refers to data describing information sources such as those on a Web site like DSAL. This data allows search engines to find and classify resources. The creation of widely accepted standards for the structure and content of metadata has been an important recent development in information technology. The DSAL and DDSA programs have decided to implement the Dublin Core as the metadata system for these programs in accordance with guidelines outlined by the Library of Congress. Among the various metadata standards, Dublin Core is being widely adopted in the academic world. DSAL also incorporates generic metadata to ensure that crawler-based search engines can index the site. More about Dublin Core.
MARC21, AACR2 & OAI
For bibliographic records, DSAL adheres to the Anglo-American cataloguing rules, 2nd rev. ed. together with the Library of Congress Rule interpretations and presents the records according to the Machine-Readable Cataloging (MARC) standard. To aid in the discovery of resources by readers, DSAL uses the Open Archives Inititiative technical framework.
Software & Technology
Whenever possible, DSAL is committed to using open-source software and contributing to the open-source community.
The current open-source software are currently in use on DSAL:
Drupal
Map Tiler
Internet Archive Bookreader
Archiving & Preservation
In order to avoid the difficulties of proliferation and obsolescence with regard to compression software, DSAL avoids compressing and decompressing data as much as possible. Some of the files are large, but the continuing reductions in the price of digital media make this approach practical. Images from the Web site are currently either gifs or jpegs. However, DSAL archives tiff files for these images because tiffs contain the most information of any image format. DSAL does not touch up tiffs, gifs or jpegs.

Data Storage
The server for DSAL and DDSA uses two tape systems as well as another server to backup the entire Web site. Back-ups occur daily. In order to further secure the data against the possibility of damage to the facility where the back-ups occur, a copy of the data is stored away from the site each week. In addition to the data on the Web site, archived material such as the tiff files used to prepare gifs and jpegs are also backed-up on CDs. The data storage plan also includes the following procedures to ensure the integrity of the storage media.
    • Periodic checks of completeness and functionality of the media.
    • Periodic refreshing and/or copying the resources in order to guard against the degradation of media.
    • Migration to new media or new formats.
    • Saving files in their primary format.
    • Preserving the technology used in the creation/storage of the files.
Web Accessibility
In order to address the needs of users with disabilities, DSAL strives to make its resources compliant with Web Accessibility Initiative guidelines.
In 1998, Congress amended the Rehabilitation Act to require Federal agencies to make their electronic and information technology accessible to the disabled. Recent legal interpretations of the act have extended the scope of the law to all state-controlled colleges and universities. The criteria for compliance with regard to Web-based technology and information are based on access guidelines developed by the Web Accessibility Initiative of the World Wide Web Consortium (W3C). These standards consider the needs of users with a variety of disabilities. People with visual disabilities will find it easier to use reading browsers because of the labeled graphics, described video, marked up tables, and guidelines for the use of color and movement. People with hearing disabilities will benefit from the captions included with audio files. Those with physical disabilities that limit their capacity to use a mouse can more easily navigate Web sites by means of keyboard and/or single-switch support for menu commands. Because users with cognitive or neurological disabilities often need a more consistent structure of information, WAI includes recommendations about data structure and display such as consistent navigation, concise language, and the elimination of flickering tags.
The World Wide Web Consortium has identified three levels of compliance with WAI. Level One compliance will remove the major barriers for users with specific disabilities. Levels Two and Three will incrementally improve the transfer of information. DSAL and DDSA Web pages will strive for Level Two compliance
There are coincidental benefits of the WAI for Web users without disabilities. For example, he various modalities of the WAI offer text only options for the users of Web phones or palm pilots with either small or even text only display screens. Clear and concise Web pages are beneficial to all users.
The Digital South Asia Library is a program of the University of Chicago and the Center for Research Libraries

Technical Information

This page was last generated on Monday 18 February 2013 at 16:44 by dsal@uchicago.edu
The URL of this page is: http://dsal.uchicago.edu/techinfo.html