SRI DAML Project Intent of Work for 2003
Grit Denker, Patrick Lincoln, and Richard Waldinger
Artificial Intelligence Center
Menlo Park, California
Jerry R. Hobbs
Information Sciences Institute
Marina del Rey, California
In our work on the DAML
project in 2003, we plan to continue with our leading roles in the development
of several key ontologies, as well as techniques for doing inference with
ontologies, especially within the context of the DAML experiment. We will complete and release an editing tool
that we have developed for defining and instantiating ontologies in DAML+OIL,
and will provide support for users. In
addition, in connection with our ARDA-funded AQUAINT project, we will pursue a
new objective of investigating the use of natural language queries in accessing
knowledge expressed in DAML.
Ontology Development and Inference
The success of the Semantic
Web depends upon the development of fundamental ontologies of very general,
widely reusable domains, such as time, space, geography, processes and
services, and security, privacy and trust; and the development of reasoning
techniques that operate over these ontologies.
We will continue our work in each of these areas.
1. Semantic Web Services. Work on DAML for Services (DAML-S), in which
we have had a leading role, and in collaboration with other members of the
DAML-S Coalition (DAML researchers from BBN, CMU, Nokia, SRI, Stanford, and
Yale), was ongoing throughout 2002, and has been productive and fruitful. In the latter half of 2002, we have been
active in the formation and initial activities of the new joint Semantic Web
Services Consortium (SWSC). In the
coming year, we plan to continue with our contributions to these efforts in at
least the following ways:
· As co-chair
of the SWSC language committee (David Martin), organize regular committee
telecons, maintain the public Web site and mailing lists for the committee, and
coordinate the activities required for making steady progress and releasing new
versions at appropriate times.
· If the
DAML-S Coalition continues as a separate body (this has not yet been decided),
continue to organize regular DAML-S Coalition telecons, maintain the DAML-S
section of daml.org, and coordinate the activities required for progress
towards Coalition goals.
to the technical development of the service profile,
process, and grounding specification languages, and the supporting ontologies
for time and resources. We expect to be
especially active in the work on process modeling, service grounding, time, and
resources, as we have been heretofore.
In particular, we expect to accomplish further generalization of the
grounding specification, and make additional progress towards the resolution of
important challenges for the process model (e.g., defining the role of a rules
language, and incorporating exceptions and transactions).
to the development of use cases for Semantic Web Services, and their
specification in a way that makes clear the real-world benefits of this
technology, and the critical technical requirements that must be met to achieve
to the development of tool specifications (such as canonical data
models and APIs) for Semantic Web Services technologies, and work with
appropriate parties towards the provision of tools that will facilitate the
adoption of this work.
· Stay abreast
of work on commercial Web services standards and tools, and reach out to that
community with our ideas about how to bring semantically rich service
descriptions onto the Semantic Web.
Monitor W3C Web services activities (in particular, the Web Services
Architecture Working Group and the Web Services Description Working Group), and
make sure the Architecture Working Group is aware of the potential
contributions of DAML-S and its descendants.
in the DAML Experiment, by providing markup and online implementations of
particular services that support the selected scenarios. This will be done in collaboration with
other Coalition participants.
· Work with
interested third parties to sustain interest in DAML-S, and get it into use.
An appropriate metric for
measuring progress in this area is the number of users, sites, and projects
that adopt DAML-S for describing their services.
2. Time. We have led in the
development of DAML-Time, an ontology of time for the Semantic Web. So far it covers topological relations,
durations, and the clock and calendar.
We have involved other researchers in this effort, including ones at the
University of Rochester, Teknowledge, Cycorp, Yale, and the University of
Western Florida. This core part of the
ontology is now complete. In 2003 we
will extend it to cover temporal granularity, temporal aggregates, and deictic
time. We will also build up resources,
useful both for the DAML Experiment and more generally, including detailed
ontologies of time zones and hours of operation. We will also bring more institutions into the DAML-Time effort,
both in North America and Europe..
3. Space. We will organize a group for developing an
ontology of space -- DAML-Space. We
want to bring into this group researchers working on modeling space from a
variety of perspectives, from those concerned with geographical and geological
ontologies to those working in areas such as the biological sciences which are
mostly concerned with the topological properties of space. We anticipate that the development of
DAML-Space will parallel the development of DAML-Time, in that the areas to be
covered are the topological relations (touch, overlap, etc.), measures of
length, area, and volume, an ontology of latitudes and longitudes, an ontology
of political divisions. In addition,
the three-dimensional character of space also will lead us to develop
ontologies of orientation and shape.
4. Geography Ontology and Inference.
We have developed a basic geographical ontology and theory in
first-order logic capable of accessing and utilizing information from a variety
of agents, including the Alexandria Digital Library Gazetteer, TerraVision, the
CIA World Factbook, Teknowledge's ASCS, and Landsat and GDACC satellite data
repositories. Using axiomatic
characterizations of these agents’ capabilities, in conjunction with SNARK's
procedural-attachment mechanism and the OAA agent library, the combined theory
is capable of finding answers that must be inferred from more than one of these
sources because no one source has the entire answer.
We plan to extend and
flesh out this line of work. We would
also like to make this accessible to DAML queries, by providing a DQL (DAML
Query Language) front end and, as the DAML family of languages becomes more
expressive, by translation into DAML itself.
Work in this area is
yielding synergistic benefits with SRI's ARDA-sponsored AQUAINT project and
NASA Intelligent Systems project, and with SRI's Terravision system. We will be able to use the results of this
research in the DAML experiment in connection with various applications
operating in the geography domain.
5. Security, Privacy, and Trust: Given the increased importance of the
World Wide Web for the military, business, industry, finance, education,
government and other sectors, security will play a vital role in the success of
the Semantic Web. It is essential that
we have tools and techniques in place that will enable us to store, manipulate,
and process the information on the Semantic Web in ways that meet security
requirements such as authentication, authorization, and data integrity, among
others. We have proposed a preliminary
core security ontology that enables us to mark-up access control restrictions
and data integrity of web pages.
In cooperation with Tim
Finin, University of Maryland, Baltimore, we will develop a security ontology
for delegation and access control.
Security mark-up is not meaningful by itself; rather, it is made meaningful
by Web applications that implement the various security techniques to protect
information exchanged in transactions. Security ties in with Web services;
therefore, we will coordinate our work on security with that of the DAML-S
coalition and the new joint consortium on services. Starting with the interest
from the last PI meeting, we will lead the effort to form a coalition to get
broad support and use for the security ontology and trust logic.
As an application
scenario, we will model security-releated issues of scenarios from the DAML
Experiment. For this purpose, we will coordinate with John Flynn and Mike Dean
to receive the necessary details on access control policy requirements in the
Experiment. This is an area where it would help us to team with a military
partner for instantiating the ontology for particular sites, because of
Our overall goal is to
develop ontologies and supporting logics that systems to model practical
security policies and to decide access control requests according to the needs
of particular instantiations.
6. Translation between DAML Language and Logic. A translator has been developed between the DAML+OIL Language
and the SRI theorem prover SNARK. The
translation is via the Specware system of the Kestrel Institute and a Specware
formulation of the DAML+OIL axioms.
This formulation has enabled us to use SNARK to discover
inconsistencies, redundancies, and simplifications in the DAML axioms. During the next year, we will extend this to
OWL, to the DAML Query Language (DQL), and to a DAML syntax for logic. This extension will enable us to use
existing SNARK theories (e.g., for geography) to answer questions which require
inference and access to procedurally attached agents, such as the Alexandria Digital
Library Gazetteer. We will also be able
to diagnose the forthcoming OWL axioms for inconsistencies and other flaws.
Plug-in for Protégé-2000
We have implemented a tool
that allows the user to read, manipulate, and write DAML+OIL ontologies using
Protégé-2000. We chose Protégé-2000 for
its user-friendly and adaptable interface, its open-source license and good
developer support, and its wide acceptance among knowledge engineers in
research and practice. The current version of the plug-in parses DAML+OIL
specifications (without instances) using the Jena API parser and transforms the
triple model into Protégé-2000 frames.
Using user-definable Protégé-2000 forms, we designed a GUI to
appropriately represent all DAML+OIL specific constructs (such as restrictions,
logical definitions, and class or property inheritance). We have pre-released
an initial version of the DAML plug-in for Protégé-2000. We recently made the software and a user
guide available at http://www.ai.sri.com/daml/DAML+OIL-plugin.
We will finish the
implementation of the DAML+OIL plug-in and extend its functionality to handle
instances and the main XML datatypes. This will also allow for the
specification of restrictions that require instances (such as “one of” and
“hasValue”). We will take feedback from users into consideration in further
enhancing the functionality of the tool.
The online documentation will be frequently updated with the latest
versions of the plug-in and detailed user guidance on how to use it. We will
make the source code available through the Protégé-2000 Web site, and will
create a developer’s guide to support future implementation efforts. We expect
that future extensions or changes to the plug-in -- for example, to support the
latest version of OWL -- will be greatly facilitated by providing this material
to the public.
We will use our tool to
create core ontologies for the DAML Experiment. In particular, we expect this
tool to be instrumental in advancing our research and supporting other groups
in the tasks of creating core ontologies and populating them with instances in
the application areas such as the Foreign Clearance Guide, DAML services, and security.
Language Interface for the Semantic Web
In conjunction with our
ARDA-funded AQUAINT project, and in collaboration with the DAML team at
Teknowledge, we plan to investigate the use of DAML-expressed knowledge (as one
of several varied knowledge sources) in the context of a natural-language
question-answering system. Gemini, a
powerful NL parser developed at SRI, provides translation from natural language
into logic; software developed at Teknowledge and the University of Rochester
translates from logic into DAML; and the ASCS system at Teknowledge supports
triples-based queries of the content of the DAML-based Semantic Web. It seems natural to combine them and develop
a knowledge-query tool that provides natural language access into the world of
DAML. SNARK, SRI's first-order-logic theorem prover, will provide ontology
translation and reasoning services in support of this effort. Additional information about this effort is
available at our AQUAINT project page: http://www.ai.sri.com/aquaint.
For a project like DAML, whose
primary mission is to have an impact on the world, the most appropriate measure
is the number of users of the ontologies and tools we develop. Good results on controlled experiments mean
nothing if no one is using DAML. Our
goal will be to make the DAML+OIL Protégé plug-in widely available and to
support its use, in an effort to maximize its use in the DAML community. Similarly, the number of users of the
services, temporal, spatial, geographical, and security ontologies is the most
appropriate metric of their success. An
intermediate metric for ontologies is the number of teams that are involved in
their development, since wide acceptance and use is promoted by early
buy-in. An intermediate metric for the
tools we develop is how well they integrate with other tools and contribute to
an overall task (for example, in the DAML experiment), since easy integration
promotes wide use.