Report Number: CS-TR-97-1581
Institution: Stanford University, Department of Computer Science
Title: Towards Interoperability in Digital Libraries: Overview and
Selected Highlights of the Stanford Digital Library Project
Author: Paepcke, Andreas
Author: Cousins, Steve B.
Author: Garcia-Molina, Hector
Author: Hassan, Scott W.
Author: Ketchpel, Steven K.
Author: Roscheisen, Martin
Author: Winograd, Terry
Date: January 1997
Abstract: We outline the scope of the Stanford Digital Library Project
which covers five areas: user interface work, technologies
for locating information and library services, the emerging
economic perspective of digital libraries, infrastructure
technology and the use of agent technologies to support all
of these aspects. We describe technical details for two
specific efforts that have been realized in prototype
implementions. First, we describe how we employ distributed
object technology to move towards an implementation of our
InfoBus vision. The InfoBus consists of translation services
and wrappers around existing protocols to cope with the
problem of interoperability and the distributed nature of
emerging digital library services. We model autonomous,
heterogeneous library services as CORBA proxy objects. This
allows the construction of unified but extensible
method-based interfaces for client programs to interact
through. We describe how distributed objects enable the
design of communication protocols that leave implementors a
large degree of freedom. This is a benefit because the
resulting implementations can allow users to choose among
multiple performance profile tradeoffs while staying within
the confines of the protocol. The second effort we cover
describes InterPay which uses the object approach for an
architecture that helps manage heterogeneity in payment
mechanisms among autonomous services. The architecture is
organized into three layers. The top layer contains elements
involved in the task-level interaction with the services. The
middle layer is responsible for enforcing user-specified
payment policies. The lowest layer manages the mechanics of
diverse online payment schemes.
http://i.stanford.edu/pub/cstr/reports/cs/tr/97/1581/CS-TR-97-1581.pdf