The functions of the Ingest Functional Entity are illustrated in figure 4-2.
Figure 4-2: Functions of the Ingest Functional Entity
The Receive Submission function provides the appropriate storage capability or devices to receive a SIP from the Producer (or from Administration). Digital SIPs may be delivered via electronic transfer (e.g., FTP), loaded from media submitted to the Archive, or simply mounted (e.g., CD-ROM) on the Archive file system for access. Non-digital SIPs would likely be delivered by conventional shipping procedures. The Receive Submission function may represent a legal transfer of custody for the Content Information in the SIP, and may require that special access controls be placed on the contents. This function provides a confirmation of receipt of a SIP to the Producer, which may include a request to resubmit a SIP in the case of errors resulting from the SIP submission.
Evidence for Authenticity is provided by the Producer as part of the PDI in the submission, and this evidence is maintained, updated, and/or incremented by the Archive over time. The Producer may provide, or the Archive may itself define, as part of the Provenance Information, Information Property Descriptions of Information Properties which should be maintained over time, and indeed may provide Information Property Descriptions of Information Properties which do not need to be maintained over time. An Information Property is that part of the Content Information as described by the Information Property Description. An Information Property Description is a description of a part of the information content of a Content Information object that is highlighted for a particular purpose. The detailed expression, or value, of that part of the information content is conveyed by the appropriate parts of the Content Data Object and its Representation Information. For example, consider a simple digital book which when rendered appears as pages with margins, title, chapter headings, paragraphs, and text lines composed of words and punctuation. Information Property Descriptions for Information Properties that must be preserved could be expressed as ‘paragraph identification’ and ‘characters expressing words and punctuation’. The Information Properties would consist of all the book’s paragraph identifications, words, and punctuation as expressed by the Content Data Object and its Representation Information. This means that all formatting other than the recognition of paragraphs and readable text could be altered while still maintaining required preservation. The Archive may express an evaluation of the Authenticity of its holdings, based on community practice and recommendations (including best practices, guidelines, standards, and legal requirements). For example scientific Archives may have less stringent evaluation criteria than State Archives; however, the Consumer may make his/her own judgment of the Authenticity starting with the evidence obtained from PDI.
The Quality Assurance function validates (QA results) the successful transfer of the SIP to the temporary storage area. For digital submissions, these mechanisms might include Cyclic Redundancy Checks (CRCs) or checksums associated with each data file, or the use of system log files to record and identify any file transfer or media read/write errors.
The Generate AIP function transforms one or more SIPs into one or more AIPs that conform to the Archive’s data formatting standards and documentation standards. This may involve file format conversions, gathering adequate Representation Information, data representation conversions or reorganization of the Content Information in the SIPs. The Generate AIP function may issue report requests to Data Management to obtain reports of information needed by the Generate AIP function to produce the Descriptive Information that completes the AIP. This function sends SIPs or AIPs for audit to the Audit Submission function in Administration, and receives back an audit report. As a result of the audit report for example, it may be necessary to gather further Representation Information to ensure that the Content Information is understandable and usable by the Designated Community
The Generate Descriptive Information function extracts Descriptive Information from the AIPs and collects Descriptive Information from other sources to provide to Coordinate Updates, and ultimately Data Management. This includes metadata to support searching and retrieving AIPs (e.g., who, what, when, where, why), and could also include special browse products (thumbnails, images) to be used by Finding Aids.
The Coordinate Updates function is responsible for transferring the AIPs to Archival Storage and the Descriptive Information to Data Management. Transfer of the AIP includes a storage request and may represent an electronic, physical, or a virtual (i.e., data stays in place) transfer. After the transfer is completed and verified, Archival Storage returns a storage confirmation indicating (or verifying) the storage identification information for the AIP. The Coordinate Updates function also incorporates the storage identification information into the Descriptive Information for the AIP and transfers it to the Data Management entity along with a database update request. In return, Data Management provides a database update response indicating the status of the update. Data Management updates may take place without a corresponding Archival Storage transfer when the SIP contains Descriptive Information for an AIP already in Archival Storage.
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