Platforms and the Semantic Web

Platforms
and the Semantic Web

Danny Ayers

danny.ayers@gmail.com

http://dannyayers.com

Notetaking – not really necessary, just bookmark:

http://hyperdata.org/krdb2010
Questions – if I'm not clear any time, please raise your hand,
general questions at the end

Mobile phones – be discrete!
IRC -
Server: irc.freenode.net
Channel: #swig

available through a browser at: http://www.mibbit.com
Twitter tag - #krdb
(I'm @danja)

Objectives
To answer questions like :

● What is a platform?

● What are the benefits of using platforms?

● What is a Web platform?

● How can Semantic Web technologies contribute?

● How do different kinds of platforms compare, and
what analogies might be useful?

Part 1 : Platforms in General

● Defining “Platform”

● A Plethora of Platforms

● Working with Web Platforms

[a <http://dbpedia.org/resource/Coffee_break>]

Part 2 : Semantic Web Platforms

● Review of Semantic Web Technologies

● Semantic Web Platforms

● The Web as Platform

“Platform” (“Piattaforma”)
● a raised horizontal surface (palco)

● political program - a document stating the
aims and principles of a political party
things
●the combination of a particular computer which
and a particular operating system support
something
●weapons platform - any military structure else
or vehicle bearing weapons

●platform shoe, chopine - a woman's shoe
with a very high thick sole (zeppa)

Source: Wordnet

“Platform”

● platform shoe, chopine - a woman's
shoe with a very high thick sole
(zeppa)

Source: Wordnet

Source : http://en.wikipedia.org/wiki/Chopine

Source: http://www.flickr.com/photos/uggboy/4392602469

“...your ladyship is nearer to
heaven than when I saw you last
by the altitude of a chopine.”
- William Shakespeare
Hamlet (1602), Act 2 Scene 2

Working Definition
A platform is a system designed to keep developers
and users out of the mud and closer to heaven.

Una piattaforma è un sistema progettato per
mantenere gli sviluppatori e gli utenti fuori dal fango e
più vicino al cielo.

Layered Models

Layer n + 1

Supports Depends on

Layer n

Supports Depends on

Layer n - 1

A Plethora of Platforms
loose taxonomy:

● Abstract Platforms

● Workbench Platforms

● Dedicated Platforms

Abstract Platforms

What do they support? : Ideas
● branches of mathematics
e.g. geometry, logic

● the sciences

● human languages

● the arts

Geometry

Typical mode of use : modelling physical systems

Applications : surveying (earth-measuring),
architecture, engineering...

Physics

Source: http://www.igdb.co.uk/

Logic
(propositional, just declarative statements)

A
& C
B

C=A∧B

Typical mode of use : modelling electronic systems

Applications : control circuits, building computers...

Logic
(adding predicates and quantifiers)

(∃x)(∃y)(Go(x) ∧ Person(John) ∧ City(Boston) ∧ Bus(y)
∧ Agnt(x,John) ∧ Dest(x,Boston) ∧ Inst(x,y))


Typical mode of use : modelling physical systems

Applications : knowledge representation & processing

Source: John F. Sowa, http://www.jfsowa.com/krbook

Conceptual Graphs
(a dialect of Common Logic)


Concepts :
Named Entities : John, Boston

Entity Types : Person, Go, City, Bus

Relations : Agnt (Agent), Dest (Destination), Inst (Instrument)

Source: John F. Sowa, http://www.jfsowa.com/krbook

CGs : Alternative Notations
Graphical

[Person: John] [City: Boston] [Go: *x] [Bus: *y]
(Agnt ?x John) (Dest ?x Boston) (Inst ?x ?y) CGIF

(exists ((x Go) (y Bus))
(and (Person John) (City Boston) CLIF
(Agnt x John) (Dest x Boston) (Inst x y)))
Source: ISO/IEC 24707

Natural Language to CGs

John is going to Boston by bus.
Informal

The person John is the agent of some instance of
going, the city Boston is the destination, and a bus is
the instrument.
Formal

Conceptual Graphs can be derived from
Natural Language.

Conceptual Graphs express knowledge
in a formal mathematical language.

But why should we care about
something so abstract?

Case Study : Legacy Re-engineering

Analyze software and documentation of a large corporation.

Generate :

● English glossary of all terms with pointers to the software

● Structure diagrams of the programs, files, and data

● List of discrepancies between software and documentation

Source: John Sowa, http://www.jfsowa.com/talks/iss.pdf

Software

1.5 million lines of COBOL programs in daily use, some of
which up to 40 years old

Documentation

100 megabytes of English reports, manuals, e-mails, Lotus
Notes, HTML, and program comments


COBOL Examples
IDENTIFICATION DIVISION.
PROGRAM-ID. HELLO-WORLD.
PROCEDURE DIVISION.
DISPLAY 'Hello, world'.
STOP RUN.

ADD YEARS TO AGE

age = age + years

“The use of COBOL cripples the mind; its teaching should, therefore, be regarded
as a criminal offense." - Dijkstra

Source : http://en.wikipedia.org/wiki/Cobol


A major consulting firm had estimated that the job would take
40 people two years to analyze the documentation and
determine the cross references.



Approach

● Translate the COBOL programs to Conceptual Graphs

● Use the Conceptual Graphs from COBOL to interpret the
English

● Use the Analogy Engine to compare the graphs derived
from COBOL to the graphs derived from English

● Record the similarities and discrepancies



VivoMind Analogy Engine

Three methods of analogy:

1. Matching labels:
* Compare type labels on conceptual graphs.

2. Matching subgraphs:
* Compare subgraphs independent of labels.

3. Matching transformations:
* Transform subgraphs.

Source: John Sowa, http://www.jfsowa.com/talks/mitre.htm

Excerpt from the Documentation
The input file that is used to create this piece of the Billing
Interface for the General Ledger is an extract from the 61 byte file
that is created by the COBOL program BILLCRUA in the Billing
History production run. This file is used instead of the history file
for time efficiency. This file contains the billing transaction codes
(types of records) that are to be interfaced to General Ledger for
the given month.
For this process the following transaction codes are used: 32 —
loss on unbilled, 72 — gain on uncollected, and 85 — loss on
uncollected. Any of these records that are actually taxes are
bypassed. Only client types 01 — Mar, 05 — Internal
Non/Billable, 06 — Internal Billable, and 08 — BAS are selected.
This is determined by a GETBDATA call to the client file.

Note that none of the files or COBOL variables are named.

By matching the English graphs to the COBOL graphs, VAE
identified all the file names and COBOL variables involved.

Job finished in 8 weeks by two programmers, Arun Majumdar
and André LeClerc.

● Four weeks for customization: Design, ontology, and
additional programming for I/O formats.

●Three weeks to run English parser + VAE + extensions:
VAE handled matches with strong evidence (close semantic
distance). Matches with weak evidence were confirmed or
corrected by Majumdarand LeClerc.

● One week to produce a CD-ROM with integrated views
of the results: Glossary, data dictionary, data flow diagrams,
process architecture, system context diagrams.



Contradiction Found by VAE

From analyzing English documentation:

● Every employee is a human being.
● No human being is a computer.

From analyzing COBOL programs:

● Some employees are computers.

What is the reason for this contradiction?



In 1979 a COBOL programmer made a quick patch :

● Two computers were used to assist human consultants.

● But there was no provision to bill for computer time.

● Therefore, the programmer named the computers Bob and
Sally, and assigned them employee IDs.



For more than 20 years:

● Bob and Sally were issued payroll checks.

● But they never cashed them.

VAE discovered the two computer “employees.”


Why should we care about
abstract platforms?

- concrete benefits.

All models are wrong.
Some are useful.
- George E. P. Box

A Plethora of Platforms
loose taxonomy:

● Abstract Platforms
● Workbench Platforms

● Dedicated Platforms

Workbench Platforms

What do they support? :

tools and raw materials

...but end product will often be
indirect

A “Jig”
- a device that holds a piece of work and
guides the tools operating on it

User Interface

* stuff *

Hardware

Traditional Stack

Source : http://en.wikipedia.org/wiki/Operating_system

Platform-Oriented Stack

User Interface
Platform(s)

Source : http://en.wikipedia.org/wiki/Operating_system

Database as Platform
Users and Developers

User
Interface Forms/Reporting
Queries/Stored Procedures

Platform Database

Operating System

Hardware

Virtual Machine as Platform

User
Applications
Virtual Machine
Operating System

Hardware

- little difference from traditional stack

Java Platform

Source : http://en.wikipedia.org/wiki/Java_(software_platform)

- Java Style
User Developer
Applications Coding Tools
JRE JDK
JVM
Operating System

Hardware

- Squeak Style

Users and Developers

Applications & Coding Tools

System Image

VM
Operating System

Hardware

(See also : emacs)

Workbench as Platform

User/Developers

Applications Coding Tools
Workbench

Runtime Compiler
VM
Operating System

Hardware

Eclipse Workbench – for developer

“Jig”- a device that holds a piece of work and guides the tools
operating on it
<project name="Gradino" default="go" basedir="../">



<property name="src.dir" value="src"/>
<property name="build.dir" value="classes"/>
<property name="lib.dir" value="lib"/>

<property name="scala-compiler.jar" value="/usr/share/scala/lib/scala-compiler.jar"/>
<property name="scala-library.jar" value="/usr/share/scala/lib/scala-library.jar"/>



<path id="scala.classpath">
<pathelement location="${scala-compiler.jar}"/>
<pathelement location="${scala-library.jar}"/>
<fileset dir="${lib.dir}">
<include name="**/*.jar" />
</fileset>
</path>

An Eclipse Application : XMind

Eclipse Platform

● Core functionality : fairly generic app stuff

● Built on a mechanism for discovering, integrating,
and running modules called plug-ins

● Plug-ins represented as bundles based on the
OSGi * specification

(* originally Open Services Gateway initiative)

Dedicated Platforms

What do they support? : Tasks

Typical Functions of a Dedicated Platform

User Interface

Raw Input Processing Output

Storage

Dedicated Platforms

Two examples:

● Recording Studio

● Content Management System

Dedicated Platform – my home studio

Dedicated Platform – Wordpress

Dedicated Platform

Monitoring

User Input

Processing Interconnection
Storage

Core Processing, Interconnection, Storage
EnergyXT Digital Audio Workstation (DAW)

Core Processing, Interconnection, Storage

Virtual wiring (also supports
software plugins) Virtual mixer

storage on filesystem

To some extent modular, via Plugins

Links are simple...

but...

Multiple Wire Protocols & Connectors

Instrument
audio MIDI

Mic audio Line audio


MIDI
in/out
Instrument
audio out

Power in

- HTML

MIDI
in/out
Instrument
audio out

HTML

<!DOCTYPE html>

<html>
...
<h2>
<a href="http://localhost/wordpress/?p=4">Hello localhost!</a>
</h2>

<p>This is some sample text which doesn’t really</p>
<p>say a lot</p>
…
</html>

RSS

...
<item>
<title>Hello localhost!</title>
<link>http://localhost/wordpress/?p=4</link>
<pubDate>Wed, 15 Sep 2010 14:31:01 +0000</pubDate>
<dc:creator>admin</dc:creator>
<description><![CDATA[This is some sample text which
doesn’t really say a lot]]></description>
</item>
...

System Characteristics :
Recording Studio

● Raw Input : instrument output/sounds
(various acoustic/electrical signals)

● Output : music (combined and more structured
acoustic/electrical signals) sometimes

● Processing : analog & digital signal processing and mixing

● Storage : computer filesystem

● User Interface : core DAW GUI, plus per-module UI

Data Characteristics : Recording Studio
“Models”
● Analog Signals

● Digital Signals

● Structured Recordings (multi-track time/amplitude)

Formats
● Audio data formats (wav, aiff, mp3, CD formats)

● MIDI file format

● Proprietary DAW multi-track format

Protocols
● Analog audio (various levels/impedances)

● MIDI protocol

System Characteristics :
Content Management System

● Raw Input : human-readable text + annotations

● Output : more structured text published as Web
resources (HTTP+HTML/RSS)

● Processing : text data structured into DB, converted into
markup

● Storage : SQL Database

● User Interface : HTML in Web browser (dashboard or output)

Data Characteristics :
Content Management System
Models
● DB Schema

● Markup

Formats
● HTML

● RSS

● Binary image formats

● SQL

● (PHP)

Protocols
● HTTP

Parallels can be drawn
between different kinds of
platforms.

So what?

Problem : Impedance mismatch

I want to connect electric guitar directly to mixer, but -

● Signal from electric guitar : 2 volts @ 10 kΩ impedance

● Signal expected by mixer is 20mV @ 100Ω

Solution : DI Box
(Impedance Matching Transformer)

Impedance Matching Transformer
(DI Box)

Signal from
electric guitar Signal to mixer
(10 kΩ output (100 Ω input)
impedance)

(electricity - magnetic flux - electricity)

Problem : Impedance mismatch

I want to connect a blog feed directly to a particular aggregator,
but -

● Signal from blog is RSS 2.0

● Signal expected by aggregator is Atom

Impedance Matching Transformer

Signal from blog Signal to
(RSS 2.0) XSLT aggregator
Engine (Atom)

Stylesheet

(xml/internal representation/xml)

Spaghetti
Modular Audio Synthesizers

User Interface Design

Output
Input Output
Oscillator Filter

User Interface Design

Yahoo! Pipes – approaching Spaghetti?

Parallels can be drawn
between different kinds of
platforms.

So what?

Problems in one domain may
have been solved in another.

Problem : multitrack structures not
available outside DAW for other tools

● proprietary format only

● vafanculo, need to talk to their developers

Wordpress Export

“When you click the button below WordPress will create an XML
file for you to save to your computer.

This format, which we call WordPress eXtended RSS or WXR,
will contain your posts, pages, comments, custom fields,
categories, and tags.”

End
Dedicated Platforms Tasks
Products

Workbench Platforms Tools

Abstract Platforms Ideas

Layered Models Revisited

Layer n + 1

Abstracts

Layer n

Abstracts

Layer n - 1

Open Systems Interconnection
(ISO, 1980's)

Source : http://www.tutorial5.com/content/view/26/79/

OSI Model Revisited

Application Protocol HTTP
+ Web-friendly formats

TCP/IP

Ethernet/WiFi

Snowflake APIs
Only one of each

Heterogenous Interfaces

● Wave hands in an abstract fashion

● Slap forehead

User

User Interface
(Application)

Platforms

Hardware

User

User
Interface

Platform

Hardware


● Review of Semantic Web Technologies

● Semantic Web Platforms

● The Web as Platform

Semantic Web

- a quick review

Aim

To extend the Web to act as a
single global database

- using what we know works

One Web!

Documents Data

Semantic Web = Web of Data

Informed by :

● Traditional RDBMS & other kinds of data store

● Logics

● Grids

● “The Cloud”

● Hypertext and the Web!

Logical Base

● open world assumption

● uniform identifiers

● declarative sentences

What works on the Web?

● Uniform Identifiers (URIs)
– for resources

● Common Interface Protocol (HTTP)

● Standard Representation Formats
(notably HTML)

Altogether: a REST Configuration

A hyperlink

page.html home.html

<a href=”http://example.org/home.html“>
Home Page
</a>

Evolving the Link

page.html home.html

home

<a href=”http://example.org/home.html”
rel=”home”>
Home Page
</a>

page home

x:home

<rdf:Description
rdf:about=”http://example.org/page”>
<x:home
rdf:resource=”http://example.org/home” />
</rdf:Description>

Relational View

x:home
subject object
http://example.org/page http://example.org/home
... ...

<rdf:Description
rdf:about=”http://example.org/page”>
<x:home
rdf:resource=”http://example.org/home” />
</rdf:Description>

Logic Notations Again
[Person: John] [City: Boston] [Go: *x] [Bus: *y]
(Agnt ?x John) (Dest ?x Boston) (Inst ?x ?y) CGIF

@prefix : <http://example.org/#> .
:John a :Person .
:Boston a :City .
_:x a :Go .
_:y a :Bus .
_:x :Agnt :John .
_:y :Dest :Boston . RDF :
_:x :Inst _:y . Turtle/N3 Syntax

Saved as cg.n3

NTriples

<http://example.org/#John> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://example.org/#Person> .

<http://example.org/#Boston> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://example.org/#City> .

_:x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://example.org/#Go> .

_:y <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://example.org/#Bus> .

_:x <http://example.org/#Agnt> <http://example.org/#John> .

_:y <http://example.org/#Dest> <http://example.org/#Boston> .

_:x <http://example.org/#Inst> _:y .

$ rapper -i turtle cg.n3 -o ntriples

RDF/XML
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns="http://example.org/#">
<City rdf:about="http://example.org/#Boston"/>
<Person rdf:about="http://example.org/#John"/>
<Go>
<Agnt rdf:resource="http://example.org/#John"/>
<Inst>
<Bus>
<Dest rdf:resource="http://example.org/#Boston"/>
</Bus>
</Inst>
</Go>
</rdf:RDF>

$ rapper -i turtle cg.n3 -o rdfxml-abbrev

Also RDF/XML
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns="http://example.org/#">
<rdf:Description rdf:about="http://example.org/#John">
<rdf:type rdf:resource="http://example.org/#Person"/>
</rdf:Description>
<rdf:Description rdf:about="http://example.org/#Boston">
<rdf:type rdf:resource="http://example.org/#City"/>
</rdf:Description>
<rdf:Description rdf:nodeID="x">
<rdf:type rdf:resource="http://example.org/#Go"/>
</rdf:Description>
<rdf:Description rdf:nodeID="y">
<rdf:type rdf:resource="http://example.org/#Bus"/>
</rdf:Description>
<Agnt rdf:resource="http://example.org/#John"/>
</rdf:Description>
<rdf:Description rdf:nodeID="y">
<Dest rdf:resource="http://example.org/#Boston"/>
</rdf:Description>
<Inst rdf:nodeID="y"/>
</rdf:Description>
</rdf:RDF>

$ rapper -i turtle cg.n3 -o rdfxml

Tip

Use somebody else's parser!

Semantic Web Layer Cake
(circa 2001)

Source : http://www.w3.org/2001/09/06ecdl/slide170.html

Source : http://www.w3.org/2010/Talks/0823acsegp

Semantic Web Layer Cake
(circa now)

Semantic Web Platforms
Platform? It's a lib...

Part 1 : Platforms in General

● Defining “Platform”

● A Plethora of Platforms

● Working with Web Platforms

[a <http://dbpedia.org/resource/Coffee_break>]


foaf:name
rdf:type
foaf:Person
#John “John”

RDF Nodes :
●Resource = named by a URI
(do HTTP to find a representation you like)

● Blank node = “there exists”

● Literal = bunch of text

Polemic for the panel :

Search sucks.
Why lose things in the first place?

Platforms and the Semantic Web

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