IFSA World Congress -NAFIPS 2013 Edmonton, Alberta. Natalia Díaz

An approach to improve semantics in

Smart Spaces using reactive fuzzy rules

Natalia Díaz Rodríguez & Johan Lilius Turku Centre for Computer Science (TUCS),

Åbo Akademi University, Turku, Finland M.P. Cuéllar & Miguel Delgado Calvo-Flores

University of Granada, Spain

1

IFSA World Congress - NAFIPS 2013, Edmonton, Canada 25.6.13

Introduction

§  Smart Spaces (UbiComp): interoperability, working on behalf of the user, handle unanticipated situations

§  Human behaviour modelling: crucial task in AmI environments

§  Problem: Sensor data as crisp events.

2

Introduction

§  Context-awareness for machine processing and reasoning.

§  Semantic Technologies and Ontologies:

Independent knowledge sharing minimizing redundancy.

3

4

Related Work: fuzzy reasoners

Related Work: architectures

§  Different semantic storage solutions, some fuzzy extensions of SPARQL (e.g. F-SPARQL).

§  What is missing? An integrated single solution supporting: – W3C standards (RDF, OWL, SPARQL). – RDF stores with support for efficient and real-time

pub/sub event notifications. – Uncertain, imprecise expressions.

5

Our proposal: A hybrid framework for context-aware Smart Space application development

2 main components: Crisp KB and Fuzzy KB, connected by a rule engine which handles each type of event subscriptions. a.  CRISP element: SPARQL Subscription-based RDF store with

Pub/Sub architecture: Smart-M3 b.  FUZZY element: Expressive Fuzzy DL reasoner, allows

mapping to a fuzzy control system: fuzzyDL

6

7

Fuzzy KB and rules in fuzzyDL

Fuzzy KB and rules in fuzzyDL

8

Hybrid architecture proposal with fuzzy and crisp KBs

9

Equivalent queries to be executed in both crisp M3 and fuzzyDL KBs

10

Mapping of rule antecedent “IF Natalia hasStatus AwayForWeekend” to SPARQL and fuzzyDL queries.

Mapping of subscription pattern types to fuzzyDL queries

11

Conclusions

12

§  Hybrid Fuzzy-Crisp architecture whose –  Quantitative (SPARQL, event Pub/Sub) and Qualitative

(semantics + fuzzy reasoning expressive power) views allow a versatile framework for developing Smart Space applications.

–  strategy allows loosening of semantics or efficiency (depending on application needs): avoiding continuous querying for changes or fuzzy discretization-based solutions.

–  Knowledge representation & queries are + flexible §  fuzzyDL still does not support some required semantic constraints §  2 KBs = Redundancy (twofold updates) -> advantage for

optimizing execution time of different queries/ datasets

Future Directions

13

§  Rule serializers (for crisp and fuzzy architectures) §  Scalability + performance experiments in real-life applications

(reasoning, querying/updating and subscription response VS ontology size & fuzzy/crisp/hybrid rules)

§  Optimization: Semantic generalization of hybrid antecedents 1.  When strict semantics are to be preserved (we sacrifice

performance): –  IF (WeatherSituationTurku, isCurrently, VeryStormy) –> IF (WeatherSituationTurku, isCurrently, ?).

2.  Transforming patterns into crisp-only (sacrifices semantic precision): –  IF(Natalia, isVeryNearTo, JohansOffice) –> IF(Natalia, isNearTo,

JohansOffice).

Future Directions

§  Pub/sub fuzzy reasoner (->Fuzzy SPARQL?) §  Alternatives to data redundancy keeping

consistency? §  Overall: Standardization of fuzzy SPARQL extension for fuzzy reasoning will achieve more usable, flexible, personalized and adaptive Smart Spaces

14

Thank you for your attention!

Natalia Díaz Rodríguez ndiaz@abo.fi

Embedded Systems Lab. Department of Information Technologies Åbo Akademi University, Turku, Finland

TUCS (Turku Centre for Computer Science)

Department of Computer Science and Artificial Intelligence University of Granada, Spain

15