Studies FY2009

The themes of studies FY2009 are as follows:

A questionnaire survey was conducted from January 21 to February 19, 2010 to ask about the status of digitization of analog audio-visual materials and efforts for long-term preservation of digital information in domestic and foreign institutions.

Survey sheets were sent to forty leading domestic and foreign institutions playing a leading role such as national libraries, national archives, national film archives, university libraries and broadcasting corporations. Twenty institutions including the NDL responded to this survey.

For more information, please see the brief report.

To realize a large-scale digital archiving system including the NDL Digital Archiving system, the NDL conducted the following research.

This study clarified requirements for a large-scale digital archiving system, especially for digital recording media and their devices, such as data storage capacity and throughput time.

Based on the results, issues to be addressed toward the practical use of the system were examined.

The existing digital recording media including magnetic media, optical media and semiconductor memories were compared in terms of the long-term usability and preservation, based on the information resources such as authoritative literature.

This result showed a sealed semiconductor memory device using Mask ROM was the most suitable recording media for the purpose of long-term usability.

Based on the results of the comparison survey, the performance requirements of the sealed semiconductor memory device using Mask ROM, such as a communication protocol and a power-supply method, were defined.

The feasibility of the media was also assessed by designing a circuit and producing a sample chip.

Based on the result of the feasibility assessment, a prototype system with sealed semiconductor memory devices using Mask ROM was designed and developed to preserve and access digital information for a long time.

The prototype system was reviewed and the issues regarding practical use were clarified.

The major findings of the study can be summarized as follows:

• * Developing superior media in terms of longevity, volume density, access rate, and cost-effectiveness was required, because the existing digital recording media were insufficient to support a sustainable large-scale digital archiving system.
• * A sealed semiconductor memory device using Mask ROM was expected to improve longevity, volume density and cost-effectiveness.
• * The impact of noise by power supply had to be reduced for stable communication.
• * Practical evaluation such as an accelerated deterioration test of sealed semiconductor memory devices using Mask ROM was required as the next step.

The following functions are needed to ensure the long-term preservation and accessibility of digital information:

• * To manage the technical information about file formats of digital information.
• * To identify the format of a digital file accepted into an archival system.
• * To detect file formats which are obsolete or at risk of becoming obsolete in the archival system and to alert the system managers to take measures against this.

To develop a digital preservation system with the above-mentioned functions compliant with the Reference Model for an Open Archival Information System (OAIS)[*], the NDL made a prototype system and experimented with it.

[*] Conceptual model of elements and functional requirements for archiving information. ISO 14721:2003

Based on information resources such as reliable literature on the Internet, detailed research was conducted on the basic technologies of existing tools, free and open source software (FOSS) and commercial digital repository systems.

The technical information about file formats which were/had been available in Japan was researched based, for example, on reliable information resources on the Internet.

A format registry managing the technical information about file formats, software products and other technical components required to support long-term access to digital information was prototyped.

A unique automatic tool to identify file formats and obsolescence detection function were developed and implemented into this prototype with the existing identification tools.

The major findings of the study can be summarized as follows:

• * To achieve the practical use of a digital preservation system, it is necessary to approach the following issues.
  • - Accuracy improvement of the identification tools of a variety of file formats
  • - Review of the methods to enrich the technical information in the format registry
  • - Need for guidelines for determining format obsolescence
  • - Consideration of mechanisms for supporting the selection and evaluation of some automation tools for format migration of vast amounts of digital information
• * To save the cost of collecting and managing information on file formats, it is necessary to share the information about file formats, existing tools to identify file formats or codec with their developers and to establish an environment to ensure the reliability of the information.
• * It is more efficient to examine and actively adopt existing proven tools than to develop one's own system.
• * It is important to keep up on the related tools and systems and to consider a framework to use actively the information provided by the related institutions.

• A Staff member of the NDL participated in the 6th International Conference on Preservation of Digital Objects (iPRES 2009) in San Francisco in October 2009.
• The NDL co-hosted the "International Symposium on Preservation of Digital Resources and Longevity of Digital Archives" with the Research Center for Knowledge Communities University of Tsukuba on February 19th, 2010.