Intelligent Information Dissemination
Harry Behrens

Hidehiko Tanaka

Dept. of Information Engineering

Dept. of Information Engineering

University of Tokyo

University of Tokyo

Abstract

information resources:
1. the Information Retrieval (IR) problem: As
almost all of us, there is information on almost
anything imaginable and unimaginable available
on the Net. The problem is to nd speci c information with relevance to clearly de ned points ofinterest.

Using autonomous intelligent agents that converse
based on mutually accepted ontologies distributed entities can share and disseminate knowledge across system and organization boundaries. By using ontologies
that are expressed in rst order predicate-logic participating agents can query and declare knowledge ina very high-level fashion that goes beyond mere datasharing. This high-level conceptual layer of software
sits on top of a sophisticated network programming
protocol that is based on network streams. This paper will a prototype system currently being developed
at our laboratory.
12. the Information Placement problem: This
problem is essentially complementary to the IRproblem. It is the situation an information source
faces in sending its information to as many interested and relevant consumers (information sinks
as possible. This is becoming especially urgent
with dynamic publishing, the merging of broadcasting and Internet technology and the emergence of data channels [?], [?] that o er themeans to publish on-line on the Internet.

Introduction

The last years have brought dramatic developments
to the global information infrastructure. The introduction of the HTTP protocol [?] and the HTML
mark-up language [?] have brought forth explosive
growth in the utilization of networked resources.
This has triggered massive development of commercial interest which in turn has brought about largescale investments that are bringing higher and higher
bandwidth to the individual's PC.
The basic protocol infrastructure on which all of theWWW is based has been remarkably constant however: On the transport and network layer the vast
majority of all distributed systems are based on theTCP/IP protocol stack. Even though it is of coursedicult to make predictions in such a fast moving
sphere and there are e orts to change some aspects of
the IP protocol [?], it doesn't look as if the basic transport layer architecture of the Internet will change.
All of this permits us, to think about applications
and networked environments that would have beyond
all practicality only a few years ago.
This research project deals with two major problems that have arisen due to the explosive growth of

The speci c aim at this stage of the research projectis to design an infrastructure that allows intelligent
information multicasting.
This paper proceeds to describe this infrastructure
in a top-down fashion.
2Information Routing Agents

The whole system is based on set of distributed

sites that constitute the market places for the wholesystem. A site is a machine or a network that is accessible over the network and uses the same basic protocols as the other sites. 1 Each site knows about its
capabilities and its needs in terms of globally speci ed
ontologies.
Ontologies are de nitions of concepts that can bethought of as computer-processable encyclopedia entries. [?] In the context of this project they are de ned
in predicate logic using the PROLOG programming
language.
1 The underlying structure is described in [?]Using a logic programming language and its inference engine has the bene t, that veri cation such as
consistency checks can be done automatically.
Ontologies are used within a context which de nes
a basic semantic category within which the ontologicalentry should be interpreted.
Within a given context all participants use the same
ontologies. Whenever entries are changed this is immediately propagated to all participants.
2.1

The Publisher's view

One idea behind this whole project is the fact, that
more and more information providers will spend considerable e orts in pushing their information to interested clients.
Based on this assumption, we think that it is realistic to assume that information providers will spendsome e ort to annotate their data if seems probablethat the annotation information helps in delivering thecontent to the client. 2 In the system we are building, information published is annotated with metainformation placing it within an ontological context.
An example could be the the publishing of a memo ona corporate intranet, pertaining to an ongoing project
and with reference to previous documents. In such acase, the client will be publishing the document within
the context of his corporate groupware. By adding
the ontological information at the administrator level,
when new projects or new processes are created, thequality of the information can be kept relatively highwith relatively little manpower e ort.
The ontological information thus added, places thepublished memo within a semantic context. Within
this semantic context classic indexing technology canbe used to describe the document in terms of its raw
textual content within the given semantic context.
3The Consumer's view

When this article talks about consumers this does
not necessarily mean the end client with his desktop
interface. In a complex information dissemination network such as the one examined and implemented inthis project, data and information travels along potentially many-stepped lters until it gets to its nal
destinations.
2 This can already be witnessed on the WWW, where con-siderable e ort is being spent to make Web pages accessible
through the use of search engines. At this point these e orts
are mainly centered on <META> tags and nifty use of comments that are seeded with keywords.

Sites such as departments or whole corporations
will specify certain contexts within which they might
be interested in receiving information. This can refer to an on-line Web-based news channel, an intracorporate discussion forum or large corporations soliciting bids for component products along certain speci cations.
The software mechanism used is analog to that ofthe publisher: ontologies are used to de ne semantic contexts. Within these semantic contexts, more
syntax oriented queries, that correspond to the index information added by the producers, are added.
These index queries can be SQL queries, SOIF queries
such as those used by the Harvest system [?] and theNetscape Catalog Server or Z39.50 queries [?] such as
those used by many libraries and the WAIS system orjust plain textual searches.
4Summary and Conclusion

The amount of raw information available on the Internet has been growing dramatically during the last
few years and is bound to continue doing so. At thesame time connectivity is becoming better due to major investments by governments and corporations.
One of the main problems that the Internet poses
is how to route published information to the correctclients and how to retrieve desirable information. Using an approach in which both sides use logical metainformation that can be handled by autonomous network agents, we are currenly designing a prototype
system, that should demonstrate how ecient use of
distributed processing in combination with high-level
semantic content description can help solve some ofthe problems the Internet is currently facing.
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