1 Reference Linking in Project Euclid …with some thoughts on the preservation of digital collections. A presentation at the Workshop on Linking and searching

1

Reference Linking inProject Euclid

…with some thoughts on the preservation of digital collections.

A presentation at the Workshop on

Linking and searching in distributed digital libraries

University of Michigan, Ann Arbor, University Library

March 19, 2002

William R. [email protected]

Digital Library and Information Technologies

Cornell University Library

March 19, 2002 William R. Kehoe, Digital Library and Information Technology, Cornell University Library2

Context – what is Project Euclid? Requirements – the constraints for the

reference linking system Implementation – some design views Next Steps – our plans for the future Preservation – thinking long-term about

digital collections

Overview


What is Project Euclid?

A partnership of independent publishers of mathematics and statistics journals

Publishers provide born-digital versions of their print journals.

http://projecteuclid.org


Reference Linking: two viewpoints

The publisher’s point of view Links to multiple resources add value to the electronic version. MR numbers, CrossRef DOIs, web links are included in the

reference when we find them

The library’s point of view The appropriate copy problem—does a link lead to a copy for

which the library has viewing/distribution rights. Is the copy an authentic representation of the original?

Project Euclid represents publishers


Purpose

References in article files are made available as links on HTML abstract pages

<<PDF>>

<<HTML>>


Requirements

Automatic processing Extensibility to multiple reference styles Extensibility to multiple input formats Low-cost maintenance High accuracy


Implementation

ConversionConversion

ExtractionExtraction

ParsingParsing

Look-upLook-up

Creating LinksCreating Links

StoringStoring

<<PDF>>

•Title•Author and affiliation•Abstract goes here•Body•References

<<XML>>



Conversion

The converter is Derek Noonberg’s “pdftotext” utility. http://www.foolabs.com/xpdf/home.html

<<PDF>><<PDF>>



<<Text>><<Text>>



ConverterConverter


Conversion/Extractionactivity diagram


Extraction

A fragment of the perl module that extracts the references from the text version of an article


Object view

Reference

MRNum

Year

TitleDOI Journal

String

LinkedString

Parsing Method Factory

getMRNum()

getYear()

getDOI()

getTitle()

getJournal()

… more …


Parsing

Each element of a Reference is extracted by a subroutine customized for how the element appears in a particular journal style.


Look-up

•|IEEE Trans. Automat. Control|chang||||1994||||Stability, queue length and delay of deterministic and stochastic queue

•|SIAM J. Control Optim.|Dupuis||||1989||||

Query

Result set0018-9286|IEEE Trans. Automat. Control|Chang|39|5|913|1994|||95b:90029|Stability, queue length, and delay of deterministic and stochastic queueing networks.

|SIAM J. Control Optim.|Dupuis||||1989||||


Link Creation

<string>[Ar] V. ARNOLD , A-graded algebras and continued fractions, Comm. Pure Appl. Math. 42 (1989), 993 1000.</string>

<linkedString>[Ar] V. ARNOLD , A-graded algebras and continued fractions, Comm. Pure Appl. Math. 42 (1989), 993 1000. <a href="http://www.ams.org/mathscinet-getitem?mr=90h:32025" target="_blank">MR 90h:32025</a></linkedString>

An HTML anchor tag is inserted into the reference string and saved to an XML file. The User Interface module later uses the linkedString element when creating an Article Abstract page on the fly. It doesn’t have to know how to create the link.


Storing

<referenceList><reference>

<refString></refString><linkedString></linkedString><title></title><journal></journal>… more elements …

</reference><reference>

… elements …</reference>

</referenceList>

Stored as an XML file


…an HTML link on the article’s abstract page …

Display

An element in an xml file provides…

… which links to a MathSciNet page


Next Steps

More journals Adding DOIs to the abstract page Conversion from LaTeX files Digitized back issues


Addendum on Digital Preservation

Libraries and others are considering ways to preserve our digital resources for the long term.

One possible solution is the LOCKSS system (Lots of Copies Keep Stuff Safe)

Another solution is to preserve the metadata needed to describe and reconstruct a collection while preserving and providing access to the data files. The Consultative Committee for Space Data Systems has published a Reference Model for an Open Archival Information System (OAIS). Many of the persons working with digital collections in the library and archive world are using this model to plan for long-term preservation.


From the Reference Model for an Open Archival Information System (OAIS)

Archival Information Package



PreservationDescriptionInformation

PreservationDescriptionInformation

RepresentationInformation

RepresentationInformation

*

1Data

Object

DataObject

<< file >>Digital Object

<< file >>Digital Object

Content Information

Content Information

ReferenceInformation

ReferenceInformation

Provenance Information

Provenance Information

FixityInformation

FixityInformation Context

Information

ContextInformation

Most digital collections contain some form of the objects in blue.

OAIS-compliant systems also contain the metadata objects in yellow


OAIS Functional Model

From the Reference Model for an Open Archival Information System (OAIS)


For More Information…

Project Euclid—http://projecteuclid.org MR Batch Lookup—

http://www.ams.org/mrlookup-support/technical_help.html#http Consultative Committee for Space Data

Systems—http://www.ccsds.org Reference Model for an Open Archival Information System

(OAIS)—http://www.ccsds.org/documents/pdf/CCSDS-650.0-R-2.pdf

LOCKSS—http://lockss.stanford.edu

Documents

1 Reference Linking in Project Euclid …with some thoughts on the preservation of digital collections. A presentation at the Workshop on Linking and searching