Tuesday, September 8, 2020

Deprecating TimeMap for Leaflet for type/hoard maps

At long last, I have decided to replace the TimeMap library that combined an OpenLayers map with the SIMILE Timeline widget. This library has been a part of OCRE (and other type corpora) since the earliest phase of the project (late 2012/early 2013) to display the geographic distribution of hoards related to a coin type, with a timeline of hoard closing dates. Scrolling through this timeline forces hoards to appear or disappear on the map. This form of visualization has a useful function in that it might show patterns of hoards appearing in particular locations in the same time period. However, most researchers want to see all of the hoards visible on the map at once by default, and there was no way to turn on or off the appearing and disappearing of findspots when scrolling the timeline.


TimeMap: only a few hoards visible at once for RRC 50/2.


RRC 50/2: all hoards are visible in Leaflet/GeoJSON


The GeoJSON for a coin type now includes Features for each hoard, conforming to Karl Grossner's GeoJSON-T extension for date ranges for the closing date. Ideally, I would like these closing dates to be represented as a histogram rather than a timeline, as demonstrated by a prototype of WebMaps-T here. This, I believe, is a more useful visualization of of the temporal distribution of coin types. WebMaps-T is not quite ready for production yet, but I have moved forward with deprecating TimeMap, replacing it with a Leaflet map that simply shows all hoards as points, without respect to their temporal component. This at least fulfills the primary research use case: showing all of the hoards simultaneously on the map.

Monday, August 31, 2020

First pass at mapping Nomisma.org to Linked Art JSON-LD

I have made some updates to both Numishare and Nomisma.org's back-ends to facilitate improved and more consistent content negotiation. I have applied a Content-Language header to the response for coin/type pages in Numishare, based on whether the language passed via request parameter (?lang) or content negotiation by the browser settings (Accept-Language) is present within the Numishare translations. 

More importantly, though, is that the Link header has been added into the requests for coin/type URIs in Numishare (as well as the browse page, because a user can request the Atom XML or untransformed Solr XML via content negotiation). The Link headers have also been applied to the URI for any concept or concept scheme in Nomisma.org. 

This follows examples established W3C Content Negotiation by Profile draft.

A `curl -I` of a URI includes a a Link to itself as a text/html resource with rel="canonical", but it will also include a list of other comma separated  rel="alternate" resources found at the same URI, but with an array of acceptable content types (different serializations of RDF, the NUDS/XML document, KML, and/or GeoJSON) and, in some cases, an additional profile URI. 


Requesting headers for http://nomisma.org/id/rome

For most serializations of RDF that are available (RDF/XML, Turtle, and JSON-LD), the profile URI is set to http://nomisma.org/ontology#, to reflect the Nomisma data model for coins, types, and SKOS concepts. Another JSON-LD serialization is available in the Linked Art profile, https://linked.art/ns/v1/linked-art.json. It is now possible to request this profile for a Nomisma concept through content negotiation, e.g.:

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

Content negotiation was already possible in Numishare, but now the Link headers indicate to a script or robot that additional content types and profiles are available for consumption.

The Nomisma.org Linked Art JSON-LD follows the spec for People and Organizations (including dynasties) and Places. For other types of concepts in Nomisma, they are defined generally as crm:E55_Type, but are not distinguished further by material, denomination, object type, etc. We will implement these classifications as they are documented in the Linked Art specification. Here's a representation of Seleucus I according to this model: https://gist.github.com/ewg118/8ccab36087a42b71ef15ece7b160f09a. This includes the preferred label in English, the English definition, matching URIs, and memberships in the Seleucid Empire and Seleucid Dynasty. A further conneg request of the latter two URIs include further context about those organizations, including the formation and dissolution dates.

In theory, a parser capable of reading Linked Art JSON-LD for a Human Made Object (for example, a coin in our collection) can crawl from the object data into any associated Nomisma.org concept. A parser can request the HEAD for a Nomisma URI, read that a serialization for the Linked Art profile exists, request the data via content negotiation for the content type and profile, and then harvest or display additional contextual information about the entities related to the object.

I got these serializations up and running in about a day, and my next tasks will be to copy and paste these new functions into Kerameikos.org's back-end and xEAC, so that it will be possible to serialize EAC-CPF archival authorities into Linked Art JSON-LD for broader reuse in Linked Open Data systems.

Wednesday, August 12, 2020

About 3,000 BnF coins linked to Coin Hoards

I recently received an update from Julien Olivier at the Bibliothèque nationale de France of coins linked to Inventory of Greek Coin Hoards URIs from the Coin Hoards project. About 3,000 of more than 10,000 Greek coins now link to hoard URIs, about a third of which are Hellenistic coins that were already published through Hellenistic Royal Coinages. A further 2,000 or so were not connected to coin type URIs, and are therefore newly integrated into the Nomisma.org numismatic Linked Open Data ecosystem. In total, these 3,000 coins link to 95 hoards.

One of the hoards the BnF's collection covers most prominently is the Auriol Hoard (IGCH 2352), a large Archaic hoard found near Marseilles, France in 1867. It consists mainly of coins from the Greek colony of Massilia itself. This particular hoard draws 651 specimens from several collections, about 500 of which are held by the BnF.

This particular hoard is briefly mentioned in a section in Sidney Noe's 1920 Coin Hoards, which was digitized and published in the ANS Digital Library as part of the NEH-Mellon Foundation Open Humanities Book Program. The link to digital archival or bibliographic resources is under the specimen list.

Coincidentally, a proof-of-concept ID for the Auriol Hoard (http://nomisma.org/id/auriol_hoard) had been created in Nomisma.org very early in the project's history (by 2011), even though it also existed in Nomisma.org as an IGCH URI. This morning, I deprecated this ID and forwarded it to its Coin Hoards URI (by inserting a dcterms:isReplacedBy URI into the RDF that will generate an HTTP 303 See Other redirect in Nomisma's software architecture).

Tuesday, August 11, 2020

MK Berlin fully linked to Antigonid Coins Online, plus updates

Karsten Dahmen at the Münzkabinett Berlin has fully cataloged all of their coins of Demetrius Poliorcetes with the newly-published URIs from Antigonid Coins Online, which is based on Edward T. Newell's 1927 corpus. There are 119 in total from Berlin, accompanying more than 400 coins from 10 other museums. One of the most diversely represented types is Demetrius 22, which is linked to eight specimens in five museums, including three coins from Berlin.

In addition to the expansion of Berlin's coverage, some other minor fixes have occurred within the underlying data: some updates to type descriptions or other minor errors in transcription.

Monday, August 3, 2020

First steps made in the normalization of the ANS Islamic department

Following some recent upgrades to our data consistency in MANTIS in the linking of many Greek names to Nomisma URIs, I have run a first-pass cleanup of entities that appear in the authority fields in the ANS' internal curatorial FileMaker Pro database. As part of the Egyptian National Library project, a large number of Islamic rulers, dynasties, and corporate bodies were created to cover the range of entities in the ENL's collection. This work was largely undertaken by Jere Bacharach.

Recently, I attempted to run the ANS's list of names that appear in the Authority facet in MANTIS against the Nomisma.org OpenRefine reconciliation API. I have successfully matched more than 300 labels within our database to Nomisma URIs. In some cases, a single entity was represented by more than one string in our database, and so we have made some noticeable improvements in consistency. We have also filtered out any value from FileMaker that is obviously not useful. For example, several hundred three-digit number codes had been inputted. Current curatorial staff is not even aware of what these codes correspond to, and so there's really no point in publishing these values into MANTIS.

1930.168.89, an Ilkhanid coin

1930.168.89 in Arabic

Nearly all of the Nomisma URIs for people link to dynasties or corporate entities, which have been indexed into MANTIS in a "State" facet. We plan to review the relationships between these entities, as dynasties and corporate bodies have been conflated in Nomisma, and we should split these into two separate classes of concept. For example, the "Abbasids" (http://nomisma.org/id/abbasids) carry a definition that corresponds more to a corporate entity, e.g., the Abbasid Caliphate (https://en.wikipedia.org/wiki/Abbasid_Caliphate). An Abbasid Dynasty entity should also be created in Nomisma to connect rulers together by means of familial relationships, but individual governors operate under the authority of the Caliphate without being relatives in the Dynasty. An additional benefit of these entities being connected to Nomisma URIs is that translations for all of them are available in Arabic, among other languages.

The cleanup is done in an independent PHP script that processes CSV exported from FileMaker into NUDS XML for publication into Numishare. An intermediate lookup table is implemented by matching a value the relevant field in FileMaker to a key in a Google spreadsheet in order to extract a Nomisma URI in another column, if available. About 300 of 2,500 total lines have been matched to URIs. But this will be a jumping off point for doing more comprehensive cleanup and Nomisma ID creation later, as we migrate into CollectiveAccess.

Monday, July 27, 2020

126 BnF coins integrated into Antigonid Coins Online

One hundred twenty-six coins from the Bibliothèque nationale de France, recently cataloged by Julien Olivier, have been incorporated into the newly-released Antigonid Coins Online (AGCO), which so far includes the coinage of Demetrius Poliorcetes. Roughly a dozen of these coins were already accessible through AGCO upon its launch since a handful of the coins of Demetrius are cross-linked with posthumous issues in the name of Alexander the Great in PELLA (related specimens are displayed in Numishare when they link directly to a type URI or implied to be the same via skos:exactMatch).

A BnF example of Demetrius 51

There are now 433 total specimens connected to the 182 types of Demetrius Poliorcetes. Two-thirds of the types are connected to at least one physical specimens, and about 40% (77 types) of the corpus links to at least one photographed coin. This number will grow, as the majority of the ANS' coins of Demetrius have not been photographed yet.

Wednesday, July 22, 2020

ANS launches the first phase of Antigonid Coins Online

After soft-launching last week to give our partners (in the NUMiD consortium, particularly!) a chance to begin cataloging coinage, we are formally announcing the release of Antigonid Coins Online. The first phase of this project includes 182 types of Demetrius Poliorcetes from Edward T. Newell's The Coinages of Demetrius Poliorcetes (1927). We will, in time, introduce typologies for the remaining kings of this Successor dynasty.

At this juncture, it includes more than 300 coins from 11 collections, from both large and small museums. Currently, the handful of coins from the British Museum and Bibliotheque nationale de France are connected to typologies from PELLA that are the same coin type. Karsten Dahmen began cataloging Berlin's coins of Demetrius almost immediately, and a few German university museums soon followed. I updated my script for harvesting Newell references from Harvard Art Museums as well as added another dozen from MFA Boston into the master spreadsheet, which I also reprocessed from a script I had written early. The first coin of Demetrius harvested into Nomisma was actually from the Fralin Museum at the University of Virginia, since I still maintain that project. A further 200 or so were cataloged by Lauren Tomanelli, before she departed the ANS to pursue her archaeology PhD at the University of Arizona, and Peter van Alfen, who referred to the trays for those coins not yet photographed.

Demetrius 159

Additionally, Lauren drew 26 new monograms that are unique (thus far) to the coinage of Demetrius Poliorcetes, while also inserting URIs to monograms from PELLA and PCO into the types, when it is apparent they symbols are semantically identical. These coins now appear in the Hellenistic Royal Coinages union typology, and are available for comparative queries of measurements, geographic distribution, etc. The HRC project was funded by the National Endowment for the Humanities. Antigonid Coins Online was not part of the original set of deliverables for HRC, but as in many of our grant-funded projects, we always exceed expectations.