Antoine Logean's bookmarks

Introduction to RDFLib

2011-12-28T14:05:00.000+01:00

>>> import rdflib
>>> from rdflib import ConjunctiveGraph
>>> graph = ConjunctiveGraph()
>>> graph.parse("http://semantictweet.com/ecolix")
)>
>>> for triple in graph:
... print triple

Some unsorted facts about RDF

2011-09-12T09:50:00.000+02:00

Here some facts taken from the book "practical RDF" of Shelley Powers

about RDF

RDF provides a standard way of expressing graphs of data and sharing them with other people and with machines.
RDF is a language for expressing data models using statements expressed as triples. Each statements is composed of a subject, a predicate, and an object.
RDF conceptualizes anything (and everything) in the universe as a resource. A resource is simply anything that can be identified with a Universal Resource Identifier (URI). And by design, anything we can talk about can be assigned a URI.
URLs are a subset of URIs that identify where digital information can be retrieved.
Because URIs uniquely identify resources (things in the world), we consider them strong identifiers. There is no ambiguity about what they represent, and they always represent the same thing, regardless of the context we find them in.

about RDF graph model

the RDF data model is best represented by a directed labeled graph
the RDF directed graph consists of a set of nodes connected by arcs, forming a pattern of node-arc-node. Additionally, the nodes come in three varieties: uriref, blank nodes, and literals.
there are RDF data models that can be represented in RDF graphs, but not in RDF/XML. The addition of rdf:nodeIDs provided some of the necessary syntactic elements that allow RDF/XML to record all RDF graphs. However, RDF/XML still can't encode graphs whose properties (predicates) cannot be recorded as namespace-qualified XML names, or QNames.
the components of the RDF graph - the uriref, bnode, literal, and arc - are the only components used to document a specific instance of an RDF data model.
there is no rule or regulation within the RDF graph that insists that all nodes be somehow connected with one another.
an RDF graph is considered grounded if there are no blank nodes.
an instance of an RDF graph is a graph in which each blank node has been replaced by an identifier, becoming a named node.

about RDF tiple

each RDF triple is a complete and unique fact
each RDF triple can be joined with other RDF triples, but it still retains its own unique meaning, regardless of the complexity of the model in which it is included
regardless of how complex an RDF graph, it still consists of only a grouping of unique, simple RDF triples, and each is made upof a subject, predicate and object.

about urirefs

uriref within a RDF model has not to be resolvable (point to something that is accessible on the web). RDF is designed to be a generic means of recording data, it can't restrict urirefs to being "real" data sources.
URIs provide a common syntax for naming a resource regardless of the protocol used to access the resource.
A URI is only an identifier. A specific protocol does not need to be specified, nor must the object identified physically exist on the Web
you could use as URI a UUID (Universally Unique Identifier) referencing a COM or other technology components.
URL is a location of an object, while a URI can function as a name or a location.

about blank nodes

blank nodes are also called bnodes or anonymous nodes
blank nodes are nodes that did not have a URI
most RDF parsers generate an unique identifier (genid:xxxxx) for each blank nodes. This is needed to distinguish blank nodes from each others within the single instance of the graph.
blank nodes are never merged in a graph because there is no way of determining whether two nodes are the same.

about literals

a literal consist of three parts: a character string and an optional language tag and data type.
literals represent RDF objects only, never subjects or predicates

about predicates

every arc (predicate), without exception, must be labeled within the graph.

Molecular substructure & similarity search

2011-08-13T04:19:00.003+02:00

Surveys

Fingerprint

Substructure Search

Structure Editorts

http://merian.pch.univie.ac.at/~nhaider/cheminf/moldb.html

Markush Suche (R-Gruppe)

Chemistry Databases

Chemoinformatics Libs

Chemistry Developement Kit (CDK)

JoeLib

http://sourceforge.net/projects/joelib/

OpenBabel

http://openbabel.org/wiki/Main_Page

LOD Visualisation using JavaScript

2011-08-13T04:16:00.000+02:00

Graphical Representation:

jQuery Sparkline
jQuery plugin generates sparklines (small inline charts) directly in the browser using data supplied either inline in the HTML, or via javascript.

Protovis

D3.js

gRaphaël

smoothiecharts

Processing.js

Geo Information :

http://openlayers.org/
Javascript mapping abstraction library mapstraction

Javascript 3D Engine
three.js

SVG

Polymaps

Word Bank is giving public access to 7000 data sets

2011-07-19T09:58:00.001+02:00

The Data Catalog of Word Bank provides now download access to over 7,000 indicators from World Bank data sets.

Schema.org: Spoonfeeding Library Data to Search Engines

2011-07-19T09:48:00.002+02:00

Not sure what Schema.org is about ? Read the nice post of Eric Hellman.

The internet of thinks

2011-07-19T08:49:00.015+02:00

Nice explanation of what the internet of thinks could be : http://blogs.cisco.com/news/the-internet-of-things-infographic/

Semantic Wiki with Referata

2011-07-12T16:46:00.001+02:00

Referata offers hosting of semantic wikis (MediaWiki + semantic MediaWiki extension ) : http://tinyurl.com/67sm9u3

Data.gov catalogs

2011-07-12T16:35:00.001+02:00

An interactive dataset containing the metadata for the Data.gov raw datasets and tools catalogs : http://explore.data.gov/Other/Data-gov-Catalog/pyv4-fkgv

DNS entries caching by Windows

2011-05-20T11:32:00.002+02:00

ipconfig /displaydns
This command shows all the dns domain name of the web servers web sites that a user has been visited.

ipconfig /flushdns:
removes that lists.

The Berlin SPARQL Benchmark

2011-05-20T11:26:00.001+02:00

The Benchmark

Query 1: Find products for a given set of generic features

SELECT DISTINCT ?product ?label

WHERE {

?product rdfs:label ?label .

?product rdf:type %ProductType% .

?product bsbm:productFeature %ProductFeature1% .

?product bsbm:productFeature %ProductFeature2% .

?product bsbm:productPropertyNumeric1 ?value1 .

FILTER (?value1 > %x%)}

ORDER BY ?label

LIMIT 10

Query 2: Retrieve basic information about a specific product for display purposes

SELECT ?label ?comment ?producer ?productFeature ?propertyTextual1

?propertyTextual2 ?propertyTextual3 ?propertyNumeric1

?propertyNumeric2 ?propertyTextual4 ?propertyTextual5

?propertyNumeric4

WHERE {

%ProductXYZ% rdfs:label ?label .

%ProductXYZ% rdfs:comment ?comment .

%ProductXYZ% bsbm:producer ?p .

?p rdfs:label ?producer .

%ProductXYZ% dc:publisher ?p .

%ProductXYZ% bsbm:productFeature ?f .

?f rdfs:label ?productFeature .

%ProductXYZ% bsbm:productPropertyTextual1 ?propertyTextual1 .

%ProductXYZ% bsbm:productPropertyTextual2 ?propertyTextual2 .

%ProductXYZ% bsbm:productPropertyTextual3 ?propertyTextual3 .

%ProductXYZ% bsbm:productPropertyNumeric1 ?propertyNumeric1 .

%ProductXYZ% bsbm:productPropertyNumeric2 ?propertyNumeric2 .

OPTIONAL { %ProductXYZ% bsbm:productPropertyTextual4 ?propertyTextual4 }

OPTIONAL { %ProductXYZ% bsbm:productPropertyTextual5 ?propertyTextual5 }

OPTIONAL { %ProductXYZ% bsbm:productPropertyNumeric4 ?propertyNumeric4 }}

Query 3: Find products having some specific features and not having one feature

SELECT ?product ?label

WHERE {

?product rdfs:label ?label .

?product rdf:type %ProductType% .

?product bsbm:productFeature %ProductFeature1% .

?product bsbm:productPropertyNumeric1 ?p1 .

FILTER ( ?p1 > %x% )

?product bsbm:productPropertyNumeric3 ?p3 .

FILTER (?p3 Query 4: Find products matching two different sets of features

SELECT ?product ?label

WHERE {

{ ?product rdfs:label ?label .

?product rdf:type %ProductType% .

?product bsbm:productFeature %ProductFeature1% .

?product bsbm:productFeature %ProductFeature2% .

?product bsbm:productPropertyNumeric1 ?p1 .

FILTER ( ?p1 > %x% )

} UNION {

?product rdfs:label ?label .

?product rdf:type %ProductType% .

?product bsbm:productFeature %ProductFeature1% .

?product bsbm:productFeature %ProductFeature3% .

?product bsbm:productPropertyNumeric2 ?p2 .

FILTER ( ?p2> %y% ) }}

ORDER BY ?label

LIMIT 10 OFFSET 10

Query 5: Find products that are similar to a given product

SELECT DISTINCT ?product ?productLabel

WHERE {

?product rdfs:label ?productLabel .

FILTER (%ProductXYZ% != ?product)

%ProductXYZ% bsbm:productFeature ?prodFeature .

?product bsbm:productFeature ?prodFeature .

%ProductXYZ% bsbm:productPropertyNumeric1 ?origProperty1 .

?product bsbm:productPropertyNumeric1 ?simProperty1 .

FILTER (?simProperty1

(?origProperty1 - 120))

%ProductXYZ% bsbm:productPropertyNumeric2 ?origProperty2 .

?product bsbm:productPropertyNumeric2 ?simProperty2 .

FILTER (?simProperty2

(?origProperty2 - 170)) }

ORDER BY ?productLabel

LIMIT 5

Query 6: Find products having a label that contains a specific string

SELECT ?product ?label

WHERE {

?product rdfs:label ?label .

?product rdf:type bsbm:Product .

FILTER regex(?label, "%word1%")}

Query 7: Retrieve in-depth information about a product including offers and reviews

SELECT ?productLabel ?offer ?price ?vendor ?vendorTitle ?review

?revTitle ?reviewer ?revName ?rating1 ?rating2

WHERE {

%ProductXYZ% rdfs:label ?productLabel .

OPTIONAL {

?offer bsbm:product %ProductXYZ% .

?offer bsbm:price ?price .

?offer bsbm:vendor ?vendor .

?vendor rdfs:label ?vendorTitle .

?vendor bsbm:country

.

?offer dc:publisher ?vendor .

?offer bsbm:validTo ?date .

FILTER (?date > %currentDate% ) }

OPTIONAL {

?review bsbm:reviewFor %ProductXYZ% .

?review rev:reviewer ?reviewer .

?reviewer foaf:name ?revName .

?review dc:title ?revTitle . OPTIONAL { ?review bsbm:rating1 ?rating1 . }

OPTIONAL { ?review bsbm:rating2 ?rating2 . } } }

Query 8: Give me recent English language reviews for a specific product

SELECT ?title ?text ?reviewDate ?reviewer ?reviewerName ?rating1

?rating2 ?rating3 ?rating4

WHERE {

?review bsbm:reviewFor %ProductXYZ% .

?review dc:title ?title .

?review rev:text ?text .

FILTER langMatches( lang(?text), "EN" )

?review bsbm:reviewDate ?reviewDate .

?review rev:reviewer ?reviewer .

?reviewer foaf:name ?reviewerName .

OPTIONAL { ?review bsbm:rating1 ?rating1 . }

OPTIONAL { ?review bsbm:rating2 ?rating2 . }

OPTIONAL { ?review bsbm:rating3 ?rating3 . }

OPTIONAL { ?review bsbm:rating4 ?rating4 . } }

ORDER BY DESC(?reviewDate) LIMIT 20

Query 9: Get information about a reviewer.

DESCRIBE ?x

WHERE {

%ReviewXYZ% rev:reviewer ?x }

Query 10: Get cheap offers which fulfill the consumer’s delivery requirements.

SELECT DISTINCT ?offer ?price

WHERE {

?offer bsbm:product %ProductXYZ% .

?offer bsbm:vendor ?vendor .

?offer dc:publisher ?vendor .

?vendor bsbm:country %CountryXYZ% .

?offer bsbm:deliveryDays ?deliveryDays .

FILTER (?deliveryDays %currentDate% ) }

ORDER BY xsd:double(str(?price))

LIMIT 10

Query 11: Get all information about an offer.

SELECT ?property ?hasValue ?isValueOf

WHERE {

{ %OfferXYZ% ?property ?hasValue }

UNION

{ ?isValueOf ?property %OfferXYZ% } }

Query 12: Export information about an offer into another schema.

CONSTRUCT {

%OfferXYZ% bsbm-export:product ?productURI .

%OfferXYZ% bsbm-export:productlabel ?productlabel .

%OfferXYZ% bsbm-export:vendor ?vendorname .

%OfferXYZ% bsbm-export:vendorhomepage ?vendorhomepage .

%OfferXYZ% bsbm-export:offerURL ?offerURL .

%OfferXYZ% bsbm-export:price ?price .

%OfferXYZ% bsbm-export:deliveryDays ?deliveryDays .

%OfferXYZ% bsbm-export:validuntil ?validTo }

WHERE {

%OfferXYZ% bsbm:product ?productURI .

?productURI rdfs:label ?productlabel .

%OfferXYZ% bsbm:vendor ?vendorURI .

?vendorURI rdfs:label ?vendorname .

?vendorURI foaf:homepage ?vendorhomepage .

%OfferXYZ% bsbm:offerWebpage ?offerURL .

%OfferXYZ% bsbm:price ?price .

%OfferXYZ% bsbm:deliveryDays ?deliveryDays .

%OfferXYZ% bsbm:validTo ?validTo }

BibSonomy

2011-05-17T00:26:00.000+02:00

A blue social bookmark and publication sharing system.

Mac Keyboard Shortcuts

2011-05-16T11:05:00.003+02:00

switch to black and white	ctrl + alt + cmd + 8
Take picture of the entire screen	cmd + shift + 3

rNews: embedding metadata in online news (RDFa)

2011-05-10T07:10:00.000+02:00

http://dev.iptc.org/rNews

A Simple Linked Data and JavaScript Tutorial

2011-05-05T07:20:00.001+02:00

http://dailyjs.com/2010/11/26/linked-data-and-javascript/

Getting data from the Semantic Web (Ruby)

2011-05-05T00:33:00.002+02:00

http://semanticweb.org/wiki/Getting_data_from_the_Semantic_Web_%28Ruby%29

publishMydata

2011-05-04T07:55:00.001+02:00

http://publishmydata.com/

Getting Started with RDF and SPARQL Using 4store and RDF.rb

2011-05-04T07:49:00.001+02:00

See the post of Jeni Tennison : http://www.jenitennison.com/blog/node/152

Open Data Directory

2011-04-26T09:12:00.000+02:00

A free search engine for open data sets published by governments, private companies and other organizations.

Informationssicherheit: Lage in der Schweiz

2011-04-21T07:08:00.001+02:00

http://www.news.admin.ch/NSBSubscriber/message/attachments/22741.pdf

How RDF Databases Differ from Other NoSQL Solutions

2011-04-17T08:30:00.002+02:00

The article by Arto (2010/04/22)

Open Data Showroom

2011-04-16T18:09:00.000+02:00

Open Data Projekte aus Deutschland, Europa und der Welt

Data visualizations for a changing world

2011-04-13T18:04:00.000+02:00

Explore the data

New Film about Open Government Data

2011-04-13T10:42:00.001+02:00

http://opengovernmentdata.org/film/

or

http://blog.okfn.org/2011/04/13/opendata-new-film-about-open-government-data/

Open Knowledge Foundation Blog

2011-04-12T16:48:00.000+02:00

http://blog.okfn.org/

Crime maps

2011-04-12T06:23:00.005+02:00

Putting Government Data online from Tim Berners-Lee

2011-04-12T06:18:00.000+02:00

Putting Government Data online from Tim Berners-Lee:

Abstract

Government data is being put online to increase accountability, contribute valuable information about the world, and to enable government, the country, and the world to function more efficiently. All of these purposes are served by putting the information on the Web as Linked Data. Start with the "low-hanging fruit". Whatever else, the raw data should be made available as soon as possible. Preferably, it should be put up as Linked Data. As a third priority, it should be linked to other sources. As a lower priority, nice user interfaces should be made to it -- if interested communities outside government have not already done it. The Linked Data technology, unlike any other technology, allows any data communication to be composed of many mixed vocabularies. Each vocabulary is from a community, be it international, national, state or local; or specific to an industry sector. This optimizes the usual trade-off between the expense and difficulty of getting wide agreement, and the practicality of working in a smaller community. Effort toward interoperability can be spent where most needed, making the evolution with time smoother and more productive.

Monisme et Dualisme

2011-04-11T12:05:00.001+02:00

Toutes les philosophies sont soit monistes soit dualistes. Les monistes pensent que le monde matériel est le seul qui existe. Les dualistes croient en un monde spirituel en plus du monde matérialiste.

Repository of Open Government Data Catalogs

2011-04-11T11:35:00.002+02:00

Repository of Open Government Data Catalogs [1]. Until now, only the Open Data initiatives led by either governments or public agencies have been published. Now, any public sector information catalog (managed by citizen movements, transparency commissions, NGOs, and other institutions) is welcomed. The only requirement is that those catalogs must contain public sector information.

The second main feature is the collaborative aspect of the catalog. Anyone may contribute submitting new catalogs using a simple form [2]. All the changes will be moderated to avoid spam or inaccuracies. After the submission an the approval, the meta-information of the initiative will be available through a SPARQL endpoint [3].

[1] http://datos.fundacionctic.org/sandbox/catalog/faceted/
[2] http://datos.fundacionctic.org/sandbox/catalog/manage/new
[3] http://data.fundacionctic.org/sparql

Freeing Greater Manchester's Public Data

2011-04-11T11:31:00.002+02:00

http://datagm.org.uk/

twouse: Semantic Web Enabled Software Engineering

2011-04-08T22:30:00.001+02:00

http://code.google.com/p/twouse/

GoodURIs

2011-04-07T04:13:00.002+02:00

What qualities make a URI work well in RDF and on the web in general?

Semantic Web Development Tools

2011-04-07T04:09:00.002+02:00

http://www.w3.org/2001/sw/wiki/Tools

Applications of Ontologies in Software Engineering

2011-04-02T12:04:00.004+02:00

From Hans-Jörg Happel and Stefan Seedorf :
The Article

Abstract. The emerging field of semantic web technologies promises new stimulus for Software Engineering research. However, since the underlying concepts of the semantic web have a long tradition in the knowledge engineering field, it is sometimes hard for software engineers to overlook the variety of ontology-enabled approaches to Software Engineering. In this paper we therefore present some examples of ontology applications throughout the Software Engineering lifecycle. We discuss the advantages of ontologies in each case and provide a framework for classifying the usage of ontologies in Software Engineering.

Documentary about the Semantic Web by Kate Ray

2011-04-02T09:52:00.004+02:00

Kate Ray, a Journalism/Psychology major at NYU made a documentary about the Semantic Web. The film gives a nice overview of what the Semantic Web is and what it is trying to achieve.

Semantic Web technologies applied to Software Engineering

2011-04-02T07:59:00.002+02:00

http://www.ifi.uzh.ch/pax/uploads/pdf/publication/1207/icse2009_tutorial.pdf

serialization involves turning a graph into a tree

2011-04-02T07:56:00.001+02:00

serialization involves turning a graph into a tree : explain

A Simple HTML5 RDFa Example

2011-04-01T17:00:00.000+02:00

http://blog.3kbo.com/2010/11/10/simple-html5-rdfa-example/

Semantic Turkey: A Semantic Web Knowledge Management and Acquisition Platform based on the Firefox Web Browser

2011-03-30T14:55:00.001+02:00

http://semanticturkey.uniroma2.it/

OWLGrEd: Editor for Compact UML-style OWL Graphic Notation

2011-03-30T14:50:00.004+02:00

http://owlgred.lumii.lv/

Open Government Data in Switzerland

2011-02-25T12:39:00.004+01:00

Articles & news

Organisations:

Blog Digitale Nachhaltigkeit

Firmen:

http://www.itopia.ch/index.de.html

Key players:

Presentations:

Open government obl_20101006

Podcasts:

Behördendaten als wertvolles Rohmaterial

Open Government Data

2011-02-25T12:17:00.001+01:00

What is open government data?

By “open” one means open as in the Open (Knowledge) Definition — in essence material (data) is open if it can be freely used, reused and redistributed by anyone.
By “government data” one means data and information produced or commissioned by government or government controlled entities.

see http://opengovernmentdata.org/

Harald Sack's blog

2011-02-21T09:10:00.002+01:00

Harald Sack's blog: http://moresemantic.blogspot.com/

Videos about linked data

2011-02-21T07:13:00.001+01:00

von Harald Sack: http://www.tele-task.de/archive/video/flash/12488/
von Georgi Kobilarov : http://www.yovisto.com/video/17144

Lexing and Parsing

2011-01-29T09:31:00.001+01:00

Lexing is the process of dividing an input stream into meaningful units, or tokens, which are then processed. Parsing refers to discovering semantic meaning out of a series of tokens according to the rules of a grammar.

RDF versus RDB-shema

2011-01-27T03:02:00.010+01:00

Fixed RDB shema :

Image taken from ontotext

The same using RDF :

Image taken from ontotext

Semantic Web Architecture

2011-01-21T19:11:00.007+01:00

Some definitions about languages

2011-01-20T13:37:00.004+01:00

A language consists of a structure definition (called abstract syntax or meta model), a definition of the notation (also called concrete syntax) and semantics. In semantics we distinguish between the static semantics (constraints, typesystem) and the operational semantics (what something means as it is executed).

Symboles terminaux et non-terminaux

2010-12-26T13:48:00.003+01:00

En informatique, on appelle symboles terminaux et non-terminaux les symboles utilisés dans les règles de production d'une grammaire formelle. Les symboles terminaux forment les morceaux de chaînes de caractères générés par la grammaire. Les symboles non-terminaux correspondent aux noms des règles de la grammaire, et produisent des séquences de symboles terminaux et non-terminaux.

Par exemple, pour représenter un nombre éventuellement signé, on peut proposer la grammaire suivante (exprimée en notation pseudo-BNF) :

::= ['-'] {}
::= '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'
Dans cette grammaire, les symboles (-,0,1,2,3,4,5,6,7,8,9) sont terminaux ; les symboles et sont non-terminaux.

Synthax versus Semantic

2010-12-16T10:23:00.004+01:00

The synthax defines the correctness of a sequence of characters without meaning. Semantic defines the meaning of this sequence of characters.
Example: 34 + 6 = 100 ist syntactic correct but semantic wrong.

Is your data 5 star ?

2010-12-09T02:01:00.004+01:00

Tim Berners-Lee suggested a 5-star deployment scheme for Linked Open Data and Ed Summers provided a nice rendering of it:

http://www.w3.org/DesignIssues/LinkedData.html

http://lab.linkeddata.deri.ie/2010/star-scheme-by-example/

Closed versus Open World Assumption

2010-06-09T14:42:00.002+02:00

Let us take an example and define the following tripels:

dog is_a mammal;
cat is_a mammal;
mammal is_an animal;
fish is_an animal
mammals have vertebra;

Based on this knowledge do have fishes vertebra ?
A first interpretation is to say that fishes have no vertebra because it is not explicitly specify. This is the "Closed World Assumption". The second interpretation says that the non-specification means that we do not know. This is the "Open World Assumption".

Tools for collaborative ontology engineering

2010-02-12T00:55:00.002+01:00

Ontoprise collaboration server
Collaborative Protégé
- http://precedings.nature.com/documents/3516/version/1/files/npre20093516-1.ppt
- online demo
- wiki
Semantic Mediawiki
OWLDiff

Internet: le réseau des réseaux

2010-02-04T08:54:00.005+01:00

"Internet est un réseau spontané, émergent, en coévolution accélérée avec son environement humain. Il est chaotique, anarchique, totalement décentralisé. Aucune administration centrale ne le dirige, personne ne le posède et plus personne ne peut arrêter son développement."

Joël De Rosnay, "L'Homme Symbiotique"

RDF Vocabulary

2010-01-30T04:41:00.006+01:00

Classes

rdf:Resource - the class resource, everything
rdfs:Literal - the class of XML literal values, e.g. strings and integers
rdf:XMLLiteral - the class of XML literal values
rdfs:Class - the class of classes
rdf:Property - the class of properties
rdfs:Datatype - the class of RDF datatypes
rdf:Statement - the class of RDF statements
rdf:Alt, rdf:Bag, rdf:Seq - containers of alternatives, unordered containers, and ordered containers (rdfs:Container is a super-class of the three)
rdfs:Container - the class of RDF containers
rdfs:ContainerMembershipProperty - the class of container membership properties, rdf:_1, rdf:_2, ..., all of which are sub-properties of rdfs:member
rdf:List - the class of RDF Lists
rdf:nil - an instance of rdf:List representing the empty list

Properties

rdf:type - an instance of rdf:Property used to state that a resource is an instance of a class
rdfs:subClassOf - the subject is a subclass of a class
rdfs:subPropertyOf - the subject is a subproperty of a property
rdfs:domain - a domain of the subject property
rdfs:range - a range of the subject property
rdfs:label - a human-readable name for the subject
rdfs:comment - a description of the subject resource
rdfs:member - a member of the subject resource
rdf:first - the first item in the subject RDF list
rdf:rest - the rest of the subject RDF list after the first item
rdfs:seeAlso - further information about the subject resource
rdfs:isDefinedBy - the definition of the subject resource
rdf:value - idiomatic property used for structured values
rdf:subject - the subject of the subject RDF statement
rdf:predicate - the predicate of the subject RDF statement
rdf:object - the object of the subject RDF statement

Simple Knowledge Organization System (SKOS)

2010-01-30T04:38:00.004+01:00

SKOS @ W3

Differences between a thesaurus and a formal ontology

2010-01-30T04:25:00.005+01:00

from SKOS Reference :

"... To understand this distinction, consider that the "knowledge" made explicit in a formal ontology is expressed as sets of axioms and facts. A thesaurus or classification scheme is of a completely different nature, and does not assert any axioms or facts. Rather, a thesaurus or classification scheme identifies and describes, through natural language and other informal means, a set of distinct ideas or meanings, which are sometimes conveniently referred to as "concepts". These "concepts" may also be arranged and organized into various structures, most commonly hierarchies and association networks. These structures, however, do not have any formal semantics, and cannot be reliably interpreted as either formal axioms or facts about the world. Indeed they were never intended to be so, for they serve only to provide a convenient and intuitive map of some subject domain, which can then be used as an aid to organizing and finding objects, such as documents, which are relevant to that domain.

To make the "knowledge" embedded in a thesaurus or classification scheme explicit in any formal sense requires that the thesaurus or classification scheme be re-engineered as a formal ontology. In other words, some person has to do the work of transforming the structure and intellectual content of a thesaurus or classification scheme into a set of formal axioms and facts. ..."

Farmer & Belin’s Criteria of Life

2010-01-25T09:15:00.002+01:00

Life is a pattern in spacetime, rather than a material object. For example, most of our cells are replaced many times during our lifetime. It is the pattern and set of relationships that are important, rather than the specific identity of the atoms.
Self-reproduction, if not in the organism itself, at least in some related organism. (Mules are alive, butcannot reproduce. Viruses can only reproduce with the aid of a host.)
Information storage of a self-representation. For example, contemporary natural organisms store a description of themselves in DNA molecules, which is interpreted in the context of the protein/RNA machinery.
A metabolism which converts matter and energy from the environment into the pattern and activities of the organism. Note that some organisms, such as viruses, do not have a metabolism of their own, but make use of the metabolisms of other organisms.
Functional interactions with the environment. A living organism can respond to or anticipate changes in its environment. Organisms create and control their own local (internal) environments.
Interdependence of parts. The components of living systems depend on one another to preserve the identity of the organism. One manifestation of this is the ability to die. If we break a rock in two, we are left with two smaller rocks; if we break an organism in two, we often kill it.
Stability under perturbations and insensitivity to small changes, allowing the organism to preserve its form and continue to function in a noisy environment, or after being subjected to minor damage.
The ability to evolve. This is not a property of an individual organism, but rather of its lineage. Indeed, the existence of a lineage is an important feature of living systems.

OWL versus UML

2010-01-25T09:13:00.004+01:00

UML (Unified Modelling Language) und OWL (Web Ontology Language) are both modelling languages with a visual syntax that have developed independently from each other but both with the idea to allow conceptualisation of real world phenomena.
UML -> Object-Oriented Programming (OOP)
OWL -> Description Logic (DL)

There are used in different contexts by different persons. UML is used for specifying, visualizing and documenting software systems. OWL is a description logic based ontology language used in knowledge representation (KR)

UML is based on close world assumption. The close word assumption states that what is not currently known to be true is false.
The counterpart is open world assumption (this is what OWL is based on), which asserts that a system’s knowledge is incomplete, so that if a statement cannot be inferred from what is represented in the system, it cannot be inferred to be false.

In UML are classes (objects) are grouped in packages. In OWL are URIs used to identify all objects. These URIs are then grouped in namespaces.

OO programming, you create the superclass first and then you derive subclasses from it. In the semantic web, you make the subclasses first, then you stick them together into a superclass.

What can UML that OWL does not can ? and what can OWL that UML does not can ?
Can we use OWL in SW engineering ?
Where do we need ontology in SW engineering ?
Is OWL not to complicated for a normal human ?

Others topics:
- OWL versus RDF
- OWL tooling
- RDF tripple store
- OWL compared with DSL

Some References:
[1] Guarino_1998_Formal_Ontology_and_Information_Systems.pdf
[2] Barry_Smith_2003_Blackwell_Guide_to_the_Philosophy_of_Computing_and_Information.pdf
[3] Brockmans_2004_A_Model_Driven_Approach_for_Building_OWL_DL_and_OWL_Full_Ontologies.pdf
[4] Brockmans_2004_Visual_Modeling_of_OWL_DL_Ontologies_Using_UML.pdf
[5] Brockmans_A_Metamodel_and_UML_Profile_for_Rule-extended_OWL_DL_Ontologies.pdf
[6] Guarino_1998_Formal_Ontology_and_Information_Systems.pdf
[7] Guus_Schreiber_2005_Lecture_part_2_on_Ontology_design_patterns.ppt
[8] Hart_2004_OWL_full_and_UML_2.0_compared.pdf
[9] Koide_OWL_vs_Object_Oriented_Programming.pdf
[10] Nils_J_Nilsson_1983_Logical_Foundations_of_Artificial_Intelligence.pdf
[11] Nils_J_Nilsson_1991_Logic_and_artificial_intelligence.pdf
[12] OMG_2009_Ontology_Definition_Metamodel_v1.pdf
[13] Xue_2008_Comparative_study_OWL_UML.pdf
Links
http://www.w3.org/TR/NOTE-rdf-uml/
http://infolab.stanford.edu/~melnik/rdf/uml/
http://swik.net/Ontology+UML

BioSpaces

2009-01-05T03:19:00.001+01:00

My GigaSpaces Demo has been approved as OpenSpaces project. There are now:

- Project Wiki Space
- Jira Project
- SVN Repository
- Project Source Insight tool (FishEye)
- Project Forum

www.mind-mapping.org

2008-11-21T11:20:00.001+01:00

The representation of knowledge in form of graphs let you visualize, classify and connect concepts, ideas, facts or anything that your mind can figure out.
Many ressources related to mind mapping can be found here.
My favorite mind-map tool is the open source XMind based on Eclipse.

MDA versus MDSD

2008-07-26T02:13:00.000+02:00

from : http://www.openarchitectureware.org/forum/viewtopic.php?showtopic=9124

"MDA does not mean that you need to have UML models. Its only one way and sometimes not the best. Further, forget about the MDA spec. It is even no specification at all, its only a "guide". And it does not work as the MDA people think. Best practices in model-driven development are to not conform to MDA, so we call this MDSD. It might be that your process is more or less like MDA suggests, but you will only be successful if you break MDA concepts.
This is a long story...

Karsten Thoms"

Xtext and Java VM configuration

2008-07-13T21:55:00.004+02:00

By developing DSLs with Xtext one usually work with two Eclipse workbenches:

one by design-time containing three projects: the grammar, the DSL-editor and the generator,
and a second one started from the first where the three DSL-plugin are deployed.

In order to avoid PermGem space problem it is important to configure properly the VM where the second runtime-workbench is started. A good setting is:

-Xms256m -Xmx512m -XX:MaxPermSize=256m

If you are working on Max OS you will possibly get the following errors : "Cannot load 32-bit SWT libraries on 64-bit JVM". To fix the problem I use the following VM parameters:

-d32 -Dosgi.requiredJavaVersion=1.5 -XstartOnFirstThread -Dorg.eclipse.swt.internal.carbon.smallFonts -XX:MaxPermSize=256m -Xms256m -Xmx512m -Xdock:icon=../Resources/Eclipse.icns -XstartOnFirstThread -Dorg.eclipse.swt.internal.carbon.smallFonts

Graphical versus textual DSLs

2008-06-28T03:05:00.000+02:00

We are presently developing for a customer a DSL that aims to map different data structures. Our solution is based an Xtext of oAW. As its name said, Xtext is a framework that enables the development of textual DSLs. Our customer was scarred when he understood that he will have to WRITE code with our DSL. He had in mind a more user friendly DSL, something more graphical.

But is a graphical DSL more user frienly? Here some advantages that textual representations have over graphical notations:

while graphical notations are often useful to describe structural concepts (e.g. class diagrams), textual notations are often a better fit for describing behavior or algorithms (e.g. expressions)
expert users often find them faster and easier to modify
there is a rich set of existing tooling for dealing with text files (diff, merge, copy & paste, search & replace ...).
by using any source control systems (CVS, SVN, ...) it is possible to manage different versions of the DSL.

The textual or graphical nature of a DSL represents only the concrete syntax of the language. The abstract syntax is anyway independant of this discussion. This means also that it should alway be possible to transform a textual representation in a graphical one and vice versa.