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A Mechanism for Managing and Distributing Information and Queries in a Smart Space Environment Sergey Boldyrev, Ian Oliver, Jukka Honkola

May 2009

Milan, Italy

Nokia Research Centre Helsinki, Finland

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Semantic Computation

Webs 1.0, 2.0

•  content oriented

· news, media

•  user publishing

· user generated content

· personal content (gmail, flickr, geotagging etc)

· folksonomies, tagging

•  search

· Google, Yahoo

Semantic Web

•  information oriented

•  classification

•  rise of the ontology

·  strict and structured

·  enables reasoning, “AI” etc

•  global information

•  internet of things

•  The Giant Global Graph

+ a Model of Computation

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Spaces •  Centralisation

·  no centralisation •  Platform heterogenous

·  reasoning, Semantic Web

·  agent/application mash-up

• Short-term availability ·  local computing resources

·  network availability

•  Long-term availability ·  Yours!

•  Data privacy ·  Your data !

•  Trust ·  keep your data to yourself

·  share when you want

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Applications m

atur

ity

time 2010 1990/2000

Device oriented Symbian, Windows, Linux

Applications

PIM

Office

local/internet connectivity

Page

Lifeblog, Lifestyle,

Maps, Widsets, Applets

Browser oriented Firefox, IE, SOA, IM ...

!!!!!!! something exciting

semantics, total integration, reasoning

location, internet enhanced,

content v presentation

Cloud/Space oriented M3

Agent?

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Application Construction

Highly Structured

Highly Unstructured

Application Construction

M3 Spaces

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Scalability

Dynamic Information

Structure

Free-form Databases

Traditional Fixed Schema Databases

Local Information

Sharing

Information Dynamicity

Scal

abili

ty (t

oday

)

Mb

Gb

Tb

Eb

Pb

modify according to Moore’s law

M3 Spaces

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M3 Philosophy

• space-based computing environment

• multiple, individual autonomous spaces · local information, reasoning, logics, ontologies etc · distributed information

· distributed deductive closure · D(S1(Q) ∪S2(Q)) ≠D(S1 (Q)) ∪D(S2 (Q))

• information sharing · RDF, Semantic Web · ontologies, tagging, folksonomies

• applications · constructed from agents · autonomous, anonymous, distributed, mobile · control-flow through ontological means

Principles of Operation: · no control flow !!??

· may be made ”outside” of the system via NoTA, UPnP, Webservices etc

· semi-structured information · no strict ontology conformance · inconsistent information allowed! · free logics · non-monotonic

· semantics of information, belief and truth maintenance responsibility of the reader (agent/actor)

· everything is information · everything is first-order

· first-order policy, security, belief and trust structures

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M3

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Abstractions

Because applications emerge from agents and spaces emerge from SIBs we abstract the traditional or legacy notion of application completely from its physical presence in any device

·  even within the UI the composition of an application is abstracted away from the agents themselves

} emerges from

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Space Provisioning

Space SIB provides 1 1..*

Connectivity

Agent

interacts with 1..* connects to 1..*

context Agent:

inv: self.connectsTo.provides=self.interactsWith

context Agent:

inv: self.connections in self.connectsTo.connectivity

connections

1..*

1..*

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Space Provisioning

Space SIB provides 1 1..*

Connectivity

Agent

interacts with 1..* routes

1..*

context Agent:

inv: self.connectsTo.provides=self.interactsWith

context Agent:

inv: self.connections in self.connectsTo.connectivity

connections

1..*

1..*

connects to

1..* *

context SIB:

inv: self.provides =self.routes.provides

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Space Provisioning

Space SIB provides 1 1..*

Connectivity

Agent

interacts with 1..* routes

1..*

context Agent:

inv: self.connectsTo.provides=self.interactsWith

context Agent:

inv: self.connections in self.connectsTo.connectivity

connections

1..*

1..*

connects to

1..* *

context SIB:

inv: self.provides =self.routes.provides

context SIB:

inv: self in self.routes+

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Space Provisioning

Space SIB provides 1 1..*

Connectivity

Agent

interacts with 1..* routes

1..*

context Agent:

inv: self.connectsTo.provides=self.interactsWith

context Agent:

inv: self.connections in self.connectsTo.connectivity

connections

1..*

1..*

connects to

1..* *

context SIB:

inv: self.provides =self.routes.provides

context SIB:

inv: self in self.routes+

Information

*

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Information Content

The information content of a space is the distributed union of all information over the transitive closure over the routes from any SIB providing that space.

Information store

KP KP KP KP

KP

Information store

SIB 3 SIB 1

KP KP

Information store

SIB 2

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Deductive Closure

Is a calculation under query over the information content of that space according to a set of rewrite rules.

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Stability

Defined in terms of metrics over: •  computation capabilities

•  uptime

•  network bandwidth

•  etc

Largest (usually) routing network Information store

KP KP KP KP

KP

Information store

SIB 3 SIB 1

KP KP

Information store

SIB 2

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Information Distribution (Current Implementation)

Insertion •  information is inserted in the the local and nearest, most stable SIB first

• propogation proceeds from there

Retraction • information is removed from the the local and nearest, most stable SIB first

• propogation proceeds from there

Query • query is broadcast across all SIBs

• preference is made to the most stable SIB

• collection and deductive closure is made locally

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RDF Structures & Signature Generation

• RDF Triples not sufficient

• Names graphs

• RDF molecules

• RDF scopes

·  molecules of various sizes

·  ranking of structures (subgraphs)

·  decided by DL expressivity

• Distribution of larger structures

• Signature Generation •  analysis of queries

•  analysis of commonly used datastructures

•  wrt deductive closure

• Kolmogrov Complexity

• Graph Factoring & Fields (Galois Connections)

• Computationally expensive

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Other Considerations

No strict client-server distinction

• SIBs replicate and forward/process queries

“Problem” Scenarios

• SIB-space-join scenario

• Space-split scenario

• Fault tolerance

· reasoning enging => handling of missing informatioin => non-monotonic reasoning

· background reconfiguratin and restoration

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Implementation and Distribution

• Client libraries for: · Python (2.5.1)

· C, C++ (inc. Symbian)

· Java, MIDP Java (TBA)

• Space Server (SIB):

· Python, C/C++ (Unix, Symbian etc)

v1.0 Release at NoTA World Conference, Berkley, USA, September 2009

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The End