A GRAPHICAL INTERFACE TO ENVIRONMENTAL META-INFORMATION

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A GRAPHICAL INTERFACE TO ENVIRONMENTAL META-INFORMATION

EnviroInfo 2007

Warsaw, 12-14 September 2007

Wolf-Fritz Riekert and Jörg Jochims

Media University Stuttgart mailto:riekert@hdm-stuttgart.de http://v.hdm-stuttgart.de/~riekert

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OVERVIEW

z Objectives

z Environmental Meta Information

z Semantic Networks

z Semantic Web

z Semantic Network Service

z Topic Maps

z Demonstration

z Features of the User Interface

z Implementation

z Result

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OBJECTIVES OF THE WORK DESCRIBED

z Construct theSNS-Navigator, a graphical interface to a semantic network containing environmental meta-information

z Make use of theSemantic Network Service (SNS) of the German Federal Environment Agency (UBA)

z Communication between the graphical interface and the Semantic network via thewebservice technology

z Use advancedXML technology

ÖXML Topic Maps (XTM) as data format

ÖScalable Vector Graphics (SVG) for the graphical display ÖXHTML for the textual display

ÖXSLT for data transformations

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ENVIRONMENTAL META-INFORMATION

Environmental meta-information

z Meta: Information about information,

describes environmental information resources

z Facilitates retrieval, processing, management of environmental information resources

Terminology needed to formulate meta-information

z Thesauri

ÖTerms plus limited number of relationship types ÖEnvironmental thesauri: UMTHES, GEMET

z Semantic Networks, Ontologies

ÖKnowledge structure more complex than in thesauri ÖChallenge: interface design

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SEMANTIC NETWORKS:

AN EXAMPLE

Source: http://en.wikipedia.org/w/index.php?title=Semantic_network&oldid=154570175

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SEMANTIC NETWORKS

z Semantic network = directed graph consisting of

ÖVertices, representing concepts (e.g., Vertebra, Mammal, Whale, Water)

ÖEdges, representing semantic relations between the concepts (e.g., “has”, “is a”, “lives in”)

z Knowledge structure more complex than in thesauri

ÖMore specific types of concepts (compared with terms) ÖLarger (unlimited) number of relationship types

z Old knowledge representation idea (Quillian,1967)

z New Web-based approaches: Semantic Web (Berners Lee)

SEMANTIC WEB

Tim Berners-Lee:

The Semantic Web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in cooperation.

Approaches:

z Resource Description Framework RDF, RDF Schema (W3C)

z Web Ontology Language OWL (RDF extension)

z XML Topic Map (alternative approach, ISO 13250) ÖUsed in this work

SNS =

SEMANTIC NETWORK SERVICE

Basis of this work: SNS = Semantic Network Service

z Developed for the German Federal Environment Agency (UBA) by an industrial working group, project leader:

Thomas Bandholtz (www.semantic-network.de).

z Thesemantic network: A topic mapintegrates three terminological information sources of the UBA in a :

ÖEnvironmental Thesaurus UmThes(“Umweltthesaurus”)

≈34000 terms

ÖEnvironmental GazetteerGTU (“Geo-Thesaurus Umwelt”) ≈19000 geographic names

ÖAn environmental chronicle≈550 environmentally- related events.

Linkage by a large number of relationship types

z The service: Multiple applications may access the semantic network remotely through a web service

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TOPIC MAPS EXAMPLE

Basic elements of a topic map:

z topics(concepts),

z associations(relationships),

z and occurences(references to information resources)

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TOPIC MAPS EXAMPLE

Navigation in a topic map:

z along associations: discovery of new knowledge

z towards occurrences: discovery of information resources Semantic web technology: knowledge added to the web

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DEMONSTRATION (1)

http://www.sns-navigator.de

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DEMONSTRATION (2)

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DEMONSTRATION (3)

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DEMONSTRATION (4)

SEARCH OPTIONS

z Search topic: text search (e.g., “animal protection”) ÖVarious search options

z Search events: indicate a time interval

z Anniversariesof environmental events

z Random searchfacility: returns an arbitrary topic

GRAPHIC REPRESENTATION OF TOPIC & ASSOCIATION TYPES

Symbols

z Topic types Colours

z Group of topic types

z Association types

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GRAPHICAL DISPLAY: NAVIGATION THROUGH TOPIC MAP FRAGMENTS

Navigation by clicking

onto the symbols

„Hovering displays dynamic content

Navigation to external resources

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IMPLEMENTATION

Three-tier architecture

z Web Browser

z SNS - Navigator

z SNS - Server of the UBA

Combination of a web application and a web service

Web Application Web Service

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WEB APPLICATION

SNS-Navigator is a web application

client server

service

para-

meter result

interface

protocol

interface data (interactive) Web Application:

A human at the client side

local computer remote computer

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WEB SERVICE

client server

local computer remote computer service

para-

meter result

interface

protocol

interface data (XML) Web Service:

A program at the client side

Server

The Semantic Network Service is a web service

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TECHNOLOGY USED

Advanced web technologies based on XML (eXtended markup language)

z SVG (Scalable Vector Graphics) used to display topic map fragments

ÖEnlargeable without loss of quality

z Ajax (Asynchronous Javascript and XML)

ÖXML Topic Maps (XTM) as data exchange format ÖA Javascript program calls the web service via a proxy ÖProcessing status can be displayed

z XSLT (eXtensible Stylesheet Language Transformation) ÖUsed to transform XTM into XHTML and SVG

representations.

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RESULT

z Graphical display makes it easy to access and understand the information content provided by the Semantic Network Service

z Ajax approach: Smooth interaction with the system, processing status is displayed

z The SVG approach facilitates the use of the system.

Environmental topics are displayed as an enlargeable network of graphical symbols.

z Develop an intuitive understanding of environmental topics

z Facilitate access to a large number of environmental information resources.