Applied Linked Data 2016-01-07

Attendees:

* Steven Anderson (BPL)

* Trey Pendragon (Princeton)

* Anna Headley (CHF)

* David Lacy (Villanova)

* Corey Harper (NYU)

Linked Data Fragments Update:

* David tried Trey's presentation code and spun it up. Worked.

Background:

* Group's project was need for a way to cache remote vocabs for local use

* LDF Spec implementation has potential to manage this

* TRiple Pattern Fragments potentially help: http://linkeddatafragments.org/in-depth/#tpf

* 2nd half of this work is how do we then use cached triples to do things like enrich URIs for use in SOLR & in UI

Converation about the current status of hosting Minted URIs (especially outside of Fedora).

CHF may be putting together a grant application that is related to our group's current interests.

Solr OCR Exclusion Update (?):

* https://issues.apache.org/jira/browse/SOLR-3191 (looks like a December comment mentioned the patch no longer works)

* Erik Hatcher reached out shortly before the Holiday, stating that he expected to rewrite the field feature over the break.

Linked Data Usage Limits (Steven Anderson):

* Library of Congress only seems to allow one hit per 3 seconds (http://id.loc.gov/robots.txt).

* In my case, would query them to get a search result for a term and then do 20 asynchrous requests to resolve each returned result (altLabels, broader, narrower mostly). This ended up having the Library of Congress block me.

* Their suggested solution is to either:

* A) Not do broader / narrower (?)

* B) Try to resolve the term directly as "http://id.loc.gov/authorities/subjects/label/[term].rdf" (So http://id.loc.gov/authorities/subjects/label/Health.json which means exact match only)

* C) Download SKOS ttl and load to a triplestore locally: http://id.loc.gov/download/

relationship between caching / proxying - to get around restrictive terms of service on providers' side.

LDP Implementation of Versioning (Memento) (Not our work, but an update)

- There's work going on for adding memento support to URIs in LDP.

Asserting Triples about External Resources + Versioning Them

- Need: not only cache URIs, but also make assertions about them. (e.g. the label is actually X)

- But probably only want to make an assertion against a specific version of a triple.

- Also probably want to record author of assertion

- https://wiki.blazegraph.com/wiki/index.php/Reification_Done_Right

- This can be done with either named graphs or reification

- May be building this type of thing in Pheonix (not Rails) (http://www.phoenixframework.org/)

Two same concepts but in different vocabularies:

* Tag twice? Use skos:exactMatch / skos:closeMatch? Etc.

* It depends?

* Probably just assert skos:exactMatch

* Historically you mint your own uri then skos:exactMatch or owl:sameAs to both terms.

* Also can wait for code from the previous conversation to be available.

* In a case that you can update the remote source (ie. Geonames), can add skos:exactMatch to other sources (ie. TGN).