Tuesday, September 1, 2020

First pass mapping EAC-CPF to Linked Art JSON-LD

After pushing updates to map people and organization concepts in Nomisma.org in Linked Art-compliant JSON, I have implemented a similar serialization into xEAC, the open source authority management framework, based on EAC-CPF, that I have been developing on and off since 2012.

Like Nomisma and Numishare projects, an HTTP request for an authority URI includes Link headers that include alternate RDF, Turtle, and JSON-LD serializations for that resource, including a JSON-LD serialization following the Linked Art profile. A capable JSON-LD parser can convert this profile into other serializations of RDF (XML, Turtle, etc.) according to the CIDOC-CRM ontology that other semantic web developers might more readily recognize.

It is therefore possible to request the Linked Art JSON-LD via content negotiation from xEAC, for example:

curl -H "Accept: application/ld+json;profile=\"https://linked.art/ns/v1/linked-art.json\"" 
     http://numismatics.org/authority/adams_edgar

The Accept header is then parsed by the XProc pipeline in a controller that reads the content-type and profile in order to choose which serialization to enact. In this case, the EAC-CPF document is transformed via an XSLT stylesheet into an intermediate XML document that represents a JSON structure of objects and arrays, which is subsequently transformed by a secondary XSLT stylesheet into a text output, to which the XProc pipeline attaches an `application/ld+json` content-type in the HTTP header. This JSON metamodel approach has been applied throughout many of my frameworks, including Nomisma.org and Numishare, in order to consistently transform various XML schemas into different JSON profiles, from Linked Art to GeoJSON to the model required by d3js for data visualization.

The mapping of EAC-CPF for people, corporate bodies, and families follows the specifications for people and organizations drafted by the Linked Art community, at https://linked.art/model/actor/. A representation of a person in the ANS archival authority system, Edgar H. Adams, includes the preferred name and biographical statement (eac:biogHist/eac:abstract), URIs for matching concepts (a xEAC-specific implementation of eac:identity/eac:entityId[@localType = 'skos:exactMatch']), birth/death (for people) and formed_by/dissolved_by (for families and corporate bodies) dates from eac:existDates, and member/member_of links to URIs that implement relevant W3C Org ontology properties to the @xlink:arcrole in an eac:cpfRelation (also a specific xEAC implementation to align EAC-CPF more directly with Linked Open Data principles).

{
  "@context": "https://linked.art/ns/v1/linked-art.json",
  "id": "http://numismatics.org/authority/adams_edgar",
  "type": "Person",
  "_label": "Adams, Edgar H. (Edgar Holmes), 1868-1940",
  "identified_by": [
    {
      "type": "Name",
      "content": "Adams, Edgar H. (Edgar Holmes), 1868-1940",
      "classified_as": [
        {
          "id": "http://vocab.getty.edu/aat/300404670",
          "type": "Type",
          "_label": "Primary Name"
        }
      ]
    }
  ],
  "exact_match": [
    "http://viaf.org/viaf/92956241",
    "http://d-nb.info/gnd/101883196",
    "http://dbpedia.org/resource/Edgar_Adams",
    "http://www.wikidata.org/entity/Q3719031",
    "http://id.loc.gov/authorities/names/n81061401",
    "http://n2t.net/ark:/99166/w6n03w0m"
  ],
  "born": {
    "type": "Birth",
    "_label": "Start Date",
    "timespan": {
      "type": "TimeSpan",
      "begin_of_the_begin": "1868-04-07",
      "end_of_the_end": "1868-04-07"
    }
  },
  "died": {
    "type": "Death",
    "_label": "End Date",
    "timespan": {
      "type": "TimeSpan",
      "begin_of_the_begin": "1940-05-05",
      "end_of_the_end": "1940-05-05"
    }
  },
  "referred_to_by": [
    {
      "type": "LinguisticObject",
      "content": "Edgar H. Adams (1868-1940) of Bayville, Oyster Bay, and Brooklyn, 
      New York, was a numismatic scholar, author, and collector who produced, among 
      other works, reference guides to territorial and private gold coins. He also 
      coauthored, with William H. Woodin, the book United States Pattern, Trial, 
      and Experimental Pieces, a standard reference work on pattern coins. He served 
      as editor of The Numismatist, the monthly journal of the American Numismatic 
      Association, wrote a numismatic column for the New York Sun newspaper, and 
      was a co-founder of the New York Numismatic Club (1908).",
      "classified_as": [
        {
          "type": "Type",
          "id": "http://vocab.getty.edu/aat/300435422",
          "_label": "Biography Statement",
          "classified_as": [
            {
              "id": "http://vocab.getty.edu/aat/300418049",
              "type": "Type",
              "_label": "Brief Text"
            }
          ]
        }
      ]
    }
  ],
  "member_of": [
    {
      "type": "Group",
      "id": "http://numismatics.org/authority/new_york_numismatic_club",
      "_label": "New York Numismatic Club"
    },
    {
      "type": "Group",
      "id": "http://viaf.org/viaf/157729460",
      "_label": "American Numismatic Association"
    }
  ]
}

Ideally, we would want to be able to include links to geographic resources for places of birth or death, occupations, and other events as machine-readable data, with actionable xs: dates and references to controlled vocabulary URIs. Some of this is already possible within xEAC because it was built from the ground up to interact with LOD resources, but projects like Social Networks and Archival Context (SNAC) aren't yet well-integrated with external resources.

Wednesday, March 4, 2020

270 hoard documents and 60 authorites added to the ANS Archives

In a major digital archival publication today, 270 documents pertaining to Greek coin hoards have been added into the ANS Digital Archives, Archer, and 60 new archival authorities have been added into the ANS Biographies (EAC-CPF records published in xEAC). These authorities include numerous prominent numismatists, archaeologists, dealers, and collectors, as well as some individuals who are not prominent--people only attested through our archives and a scant provenance records from other museums. Each of these authorities will be created or updated in the Social Networks and Archival Context (SNAC) project, along with links back to our archival records.

A nice example is Sir Arthur Evans, the famous archaeologist of Knossos. He is mentioned in several letters between Sidney Noe and other scholars. Although Evans is not a prominent scholar in our own archives, his papers are held in other institutions. We are able to make our few letters more broadly available to researchers interested in Arthur Evans through SNAC.

The record for Arthur Evans, with links to hoard documents.


The archival documents themselves represent the first portion of a larger collection of scanned letters, invoices, inventories, notes, hoard photographs, and other research materials related to The Inventory of Greek Coin Hoards and subsequent Coin Hoards volumes. Coin Hoards will be published online in the near future, after we migrate the old IGCH platform into a completely new database system that operated more like Coin Hoards of the Roman Republic.

The display of IGCH 140, with new archival documents

Under the hood, these archival records are TEI documents generated from spreadsheet metadata entered by Peter van Alfen. The images are IIIF-compliant and follow the procedures we have already established with Edward T. Newell's research notebooks. The Archer framework, EADitor, was updated to accommodate other types of archival materials represented as TEI (manuscripts, etc.), and EADitor is capable of serializing these files directly into RDF for Archer's SPARQL endpoint (that drives the interconnectivity between the authority records and archival items, as well as the display of archival items in MANTIS and IGCH). Additionally, the TEI files, and TEI-encoded annotations, are serialized dynamically into IIIF manifests.

Because all TEI files use the same annotation system in the back-end of EADitor (Masahide Kanzaki's Image Annotator: https://www.kanzaki.com/works/2016/pub/image-annotator), these new archival documents can be annotated with URIs from Nomisma.org, coins in our collection, coin types or monograms in PELLA or other corpora. As a proof of concept, I annotated the names of Mithradates VI and Lysimachus with their respective Nomisma URIs on the notes of Wayte Raymond about IGCH 973: http://numismatics.org/archives/ark:/53695/igch973.001. These annotations, stored natively in TEI surface elements within a facsimile, are serialized into JSON-LD according to the IIIF spec in real time, and displayed at the link above in Mirador. The names are also listed in the index below the Mirador viewer.

While we still have more metadata to enter for more archival documents, the data-entry workflow and processing scripts are fully established at this stage. This is the next step in transforming the IGCH database into a more comprehensive research platform for Greek coin hoards.