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Some Observations on Common Patterns in Information Technology

Prof. Dr. Franz-Josef Behr, Stuttgart University of Applied Sciences

ICTES 2014, University of Kelaniya, Sri Lanka

http://en.wikipedia.org/wiki/University_of_Kelaniya#mediaviewer/File:Unikelruki.jpg

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Outline

• Introduction • Features and collections of them, and their Identity• Encoding

– Markup Languages, Structuring vocabularies by namespaces– Key value pairs– Separating information chunks

• Standards• Openess• Networking and Service Orientation

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• Field data collection• Surveying• Photogrammetry• Remote sensing

• Mobile Apps• Geodatabeses• Spatial Data Infrastructures• Data Harmonization• Service oriented Architectures• Web Mapping• OGC WebServices• Architectures• Reports & Presentations• 3D, 4D, …

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Complexity

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Reduction ofComplexity

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Recognition ofPattern

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7 Features andcollections of them

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Features

• real world: consisting of entities / phenomena (latin: ens: a being)

• Feature = an abstraction of real world phenomena‖(ISO 19101)

• geographic feature: associated with a location relative to the Earth.

• The state of a feature is defined by a set of properties, where each property may be thought of as a {name, type, value} triple.

Real worldt

Model

Entity

feature

Identity

properties

behaviour

attributes

geometry

styling properties

meta properties

Technical viewpoint,abstraction,generalization

relationships

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feature

feature

feature

feature

feature

feature

featurefeature

feature

feature

feature

feature

feature

feature

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Single features and collections: in GML

• FeatureCollection: a collection of GML Features, having own properties and an optional list of Spatial Reference System Definitions. [1]

• GML feature collections are themselves valid GML features. [2]

<complexType name="AbstractFeatureCollectionType" abstract="true"> <complexContent> <extension base="gml:AbstractFeatureType"> <sequence> <element ref="gml:featureMember" minOccurs="0" maxOccurs="unbounded"/> <element ref="gml:featureMembers" minOccurs="0"/> </sequence> </extension> </complexContent></complexType>>

<element name="AbstractFeatureCollection" type="gml:AbstractFeatureCollectionType" abstract="true" substitutionGroup="gml:AbstractFeature" />

[1] http://www.w3.org/Mobile/posdep/GMLIntroduction.html[2] OpenGIS Geography Markup Language (GML) Encoding Standard, v 3.2.1, http://portal.opengeospatial.org/files/?artifact_id=20509

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Single features and collections: in Java

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Real worldt

Model

Entity

feature

Identity

properties

behaviour

attributes

geometry

styling properties

meta properties

Technical viewpoint,abstraction,generalization

relationships

Identity of features

• Each feature must be identifiable.

• Need of identification systems – perhaps many

• Identification also needed in networking (discussed later)

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Identity of features

<gml:featureMember> <AX_Flurstueck gml:id="DEBWL0010001UiIg"> <gml:identifier codeSpace="http://www.adv-online.de/">urn:adv:oid:DEBWL0010001UiIg</gml:identifier> <zeigtAufExternes> <AA_Fachdatenverbindung> <art>urn:bw:fdv:1000</art> <fachdatenobjekt> <AA_Fachdatenobjekt><name>0680199400016V</name></AA_Fachdatenobjekt>… <position> <gml:Surface srsName="urn:adv:crs:DE_DHDN_3GK3_BW100" gml:id="Y33">… <gml:Curve gml:id="Y34"> <gml:segments> <gml:LineStringSegment> <gml:posList>515748.750 5454798.050 515758.590 5454780.310</gml:posList> </gml:LineStringSegment> </gml:segments>… </gml:polygonPatches> </gml:Surface> </position> <gemarkung> <AX_Gemarkung_Schluessel> <land>08</land> <gemarkungsnummer>680</gemarkungsnummer> </AX_Gemarkung_Schluessel>… <flurstueckskennzeichen>08068000300592____00</flurstueckskennzeichen> <amtlicheFlaeche uom="urn:adv:uom:m2">290.00</amtlicheFlaeche>cou

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Encoding Data

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Encoding Data

Principle of MarkUp

• Markup Language• Definition of structural

elements for data• Strict syntax

End-TagElement contentStart tag with attribute

Element nameAttribute nameAttribute value

<person city="Karlsruhe">Franz-Josef Behr</person>

eXtensible

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Encoding Data

Markup Languages: XML

Aft

er:

htt

p:/

/ww

bota

.fre

e.f

r/Sam

ple

s/pars

ing.h

tm

• You can have your won Markup Language

• It‘s understandable for human beings and for computer programs

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<georss:where> <gml:Point> <gml:pos>48.947534 8.482132</gml:pos> </gml:Point></georss:where>

<georss:where> <gml:Point> <gml:pos>48.947534 8.482132</gml:pos> </gml:Point></georss:where>

<georss:point>48.947534 8.482132</georss:point><georss:point>48.947534 8.482132</georss:point>

<?xml version='1.0' encoding='UTF-8'?><kml> <Placemark> <name>48° 56' 51.120623'' N, 8° 28' 55.675049' E</name> <description></description> <Point> <coordinates>8.482132, 48.947534, 0</coordinates> </Point> </Placemark></kml>

<?xml version='1.0' encoding='UTF-8'?><kml> <Placemark> <name>48° 56' 51.120623'' N, 8° 28' 55.675049' E</name> <description></description> <Point> <coordinates>8.482132, 48.947534, 0</coordinates> </Point> </Placemark></kml>

<geo:Point> <geo:lat>48.947534</geo:lat> <geo:long>8.482132</geo:long></geo:Point>

<geo:Point> <geo:lat>48.947534</geo:lat> <geo:long>8.482132</geo:long></geo:Point>

Ambiguity of names in different XML Ambiguity of names in different XML DialectsDialects

W3C Geo

KML

GeoRSS (GML)

GeoRSS (simple)

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Solution: Structuring vocabularies by namespaces

In programming languages (here: Java)

In XML

In Database technology: context for database names

Source: ISO 19101, ISO 19115

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Key value pairs

htt

ps:

//w

ww

.car2

go.c

om

/api/v2.1

/vehic

les?

loc=

stu

ttgart

&oauth

_consu

mer_

key=

car2

gow

ebsi

te&

form

at=

jso

n&

callb

ack

=jQ

uery

171

087

9229

0978

2993

11_1

36932

4710

467&

_=

136

9324

710

759

In URLs to identify resources

in JSON

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Separating information chunks

http://www.gis-news.de/cgi-bin/mapserv.exe?img.x=348&img.y=318&zoomdir=1&zoomsize=2&layer=city&layer=motorway&layer=Europe&imgext=4.296614+49.186302+7.284114+52.174938&imgxy=274.5+274.5

http://www.gis-news.de/cgi-bin/mapserv.exe?img.x=348&img.y=318&zoomdir=1&zoomsize=2&layer=city&layer=motorway&layer=Europe&imgext=4.296614+49.186302+7.284114+52.174938&imgxy=274.5+274.5

In URLs to identify resources:

In GML encodings:

?

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Separators have to be defined:

Decimal separator (.)

Decimal separator (.)

coordinate separator (,)coordinate separator (,)

tuple separator (space)tuple separator (space)

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Source

Data

Standards

Open

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Open agenda is now implemented by the UK Government and delivering huge cost savings for government

£409 million in the first half of this year

Read on: https://www.gov.uk/government/news/government-bodies-must-comply-with-open-standards-principles

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EU Digital Agenda and Open Data

Source: http://ec.europa.eu/digital-agenda/en/blog/eu-open-data-portal-here [2014-06-21]

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Source

Data

Standards

Open

Openess

• Data must be complete.• Data must be primary.• Data must be timely.• Data must be accessible.• Data must be machine-processable.• Access must be non-discriminatory.• Data formats must be non-proprietary.• Data must be under an open license or license free.• Data must have permanence and be findable over time.• Usage costs must be affordable (de minimis).

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Standards

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Organisations and their dependencies

Establish definition of and terms of engagement in *SDI

ISO

TC 211 TC 204

JTC-1

National Standards

Organizations

Provideexpertise &candidate stds.

Review &approvestds.

Adopter/Implementer Community

Adopter/Implementer Community

OpenGISConsortium

(OGC)

World WideWeb Consortium

(W3C)

Internet Engineering Task Force (IETF)

Facilitation Bodies

• GSDI• ANZLIC• PCGIAP• FGDC • PC-IDEA• INSPIRE• GeoConnections• CODI/UNECA• AGI• …

W3C: HTTP, PNG, RDF, SOAP/XMLP (Web Services Activity), XML, Xlink, Xpath, Xpointer, XSL/XSLT, XML Schema

OGC: Web Map Server, Web Feature Server, GML, Web Coverage Server, Style Layer Descriptor, Catalog Service

ISO: Ref Model, Terminology, Conformance testing, Profiles, Spatial Schema, Temporal Schema, Feature Cataloguing Methodology, Spatial Ref by Coords and Ids, Quality, Metadata, WMS, GML, LBS, Registration of Geo-information Items

Metadata Profile, Data Content Standards, etc.

Class A liaison

XML Protocol (XMLP),XML Signature, I18N

Class C Liaison:XML, I18N

Modified after: http://www.fgdc.gov/library/presentations/documents/2003-presentations/GIS_Standards_Rockies1003.ppt [2013-05-31]

• ISPRS• ICA•…

• ASPRS• DGPF• localchapters•…

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28 SharingInteroperability

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Networking and Service Orientation

Source: http://commons.wikimedia.org/wiki/File:Social_Network_Analysis_Visualization.png

GIS = High Complexity = Empowering a Few

Web Services:Simplicity = Empowering a Billion

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Networking

• Uniform Resource Identifier (URI). URIs can be: – Locations / adresses: Uniform Resource Locator (URL) , [RFC2396]

– Names: Uniform Resource Name (URN) [RFC 1737, RFC 2141, RFC 3061]

– IP-Adresses (IPv4, IPv6)

<gml:Point srsname=“urn:adv:crs:ETRS89_UTM32“> <gml:coordinates>369949.671 5615301.383</gml:coordinates></gml:Point>

http://www.w3.org/Provider/Style/URI

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Web Gis Architecture

InternetHTTP

Webserver

HTTP

CGI protocol

Document rootStatic resources

Server side programsDynamic Generation of resources

Client"User Agent"

PNG, JPG, …XML / SVG

DBMSServer

Data preparation, analysis

SQL

Presentation Tier

Data Tier

Communication Tier,Web Tier

Application Tier,Business Logic Tier

ApplicationServer

IP address / Server Name / Host nameIP address

DNS Server

80

HTTP-ClientHTTP-ClientHTTP-Client

Local GIS

80

Communication TierCommunication Tier

Application TierApplication Tier

Data TierData Tier

Presentation TierPresentation Tier

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InternetHTTP

Webserver

HTTP

CGI protocol

Document rootStatic resources

Server side programsDynamic Generation of resources

Client"User Agent"

PNG, JPG, …XML / SVG

DBMSServer

Data preparation, analysis

SQL

Presentation Tier

Data Tier

Communication Tier,Web Tier

Application Tier,Business Logic Tier

ApplicationServer

IP address / Server Name / Host nameIP address

DNS Server

80

HTTP-ClientHTTP-ClientHTTP-Client

Local GIS

80

Architecture: The protocols

HTTPRFC 2616

HTTPRFC 2616

CGIRFC 3875

CGIRFC 3875

SQLISO/IEC 9075

SQLISO/IEC 9075

XMLw3.org/XML/

XMLw3.org/XML/

Content-TypeRFC 2045

Content-TypeRFC 2045

URIRFC 1630

URIRFC 1630

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Publish-Find-Bind-Pattern

Client

Web Service Offer

Service RegistryCatalogue

publish

„bind“ = "cosuming" the service

Find = "discover"

OGC GetCapabilities,WSDL

OGC Web Catalogue Service,

UDDI, Discovery

Service

Service Comsumer, OpenLayers

View Services, Download Services, …

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Summary / Outlook

• Several observable patterns in ICT were shown.

• Try to figure out ALWAYS the design pattern in information technology applicable for YOUR filed of work.

• Take care of standards.

• Be open regarding data, services, collaboration – be interoperable.