CONTEXT BASED ADAPTATION OF SEMANTIC RULES IN SMARTBUILDINGS

Vikash Kumar (kumar@ftw.at)Anna Fensel (fensel@ftw.at, anna.fensel@sti2.at)

Peter Fröhlich (froehlich@ftw.at)

iiWAS‘13, December 4, 2013, Vienna, Austria

Introduction: Motivation & Research Question State of the Art in Rule Exchange Approach: Towards Semantic Rules Adaptation Implementation Evaluations Conclusion

Outline

Introduction: Motivation and Research Question

Rules find increasing use in semantic applications as well as traditional IT systems for representing preferences, privacy constraints, etc.

Several initiatives aim to transform a Rule from:

However, there is little or no provision for:

© FTW - 4 -

Motivation

Rule(A), Language(X) Rule(A), Language(Y)

Rule (A), Language (X), Context (C) Rule (A), Language (X), Context (C´)

So where is the „Real Problem“??

While Semantic Data models can easily be shared across applications, the same doesn‘t apply for rules

© FTW - 6 -

Research Questions

1. How dependent are semantic policies on the contextual conditions for which they have been developed?

2. Which context parameters are included in a typical policy?

3. How dependent are the context parameters on each other?

4. Can a policy be adapted from one contextual setting to another using this knowledge and still solve the purpose for which the policy was originally created?

State of the Art in Rule Exchange

W3C received several submissions towards standardization of a Web rule language specification:

- Semantic Web Rule Language (SWRL) - Web Rule Language (WRL)- Semantic Web Services Language (SWSL)

In 2005 W3C launched a Rule Interchange Format (RIF) working group tasked with standardizing a common rule interchange format for the web

- Consists of various interconnected dialects representing rule languages

- Dialects provide a formal description of a rule‘s syntax, semantics & XML serialization

- Existing and upcoming rule languages may be mapped to this format serving as an interlingua between various languages

© FTW - 8 -

State of the Art in Rule Exchange (1)

Linked Rules: A set of basic principles by which rules can be represented and shared over the web

- Several methods of rule reuse proposed- Demonstration on N3 based AIR web rule languages

Rule Markup Language (RuleML), Reasoning on the Web with Rules and Semantics (REWERSE)

© FTW - 9 -

State of the Art in Rule Exchange (2)

Approach: Towards Semantic Rule Adaptation

This thesis focuses on contextual independence rather than language independence

The main objective is to achieve adaptation of a Policy created in a certain rule language into a different context in the same language

To achieve this we:- Identify the context parameter trigger and its inter-dependence

with other context parameters- Manipulate the dependent parameters based on the triggering

parameters

© FTW - 11 -

The Approach

*Dey, A.K., Abowd, G.D., Salber, D.: A conceptual framework and a toolkit for supporting the rapid prototyping of context-aware applications. Human-Computer Interaction 16 (2-4), 97-166, 2001.

Context Definition

Context*: Any information that can be used to characterize the situation of entities (i.e., whether a person, place, or object) that are considered relevant to the interaction between a user and an application, including the user and the application themselves. Context is typically the location, identity, and state of people, groups, and computational and physical objects.

All parameters defined wrt Sensors as subject Parameters involved:

1. Location – physical location of the sensor

2. Time – of reading the sensor value

3. Identity – Unique id of the sensor

4. Type – Sensor type (heat, light, motion, etc.)

5. State – ON/OFF, Temp reading, luminosity, etc.

6. People – Individuals or groups, co-located or distributed

Context Parameters Considered

© FTW - 14 -

Example

Send me all offers for iPad3 from

1030, Vienna on Fridays & Saturdays

Send me all offers for Samsung Galaxy tab

from 4020, Linz on Weekdays after 11 AM

rdf:type gr:computingTabletrdf:type gr:Location

rdf:type gr:DateTime

Explore how change in one context (location, time, etc.) affects other contexts

The context interdependence is described keeping in mind our use cases

Which other context parameters might need to be adapted in an ON/OFF or Alert Policy when a particular context changes

Other contexts may either Definitely get affected, Possibly get affected or Not get affected

Preserving the Semantic Idea

Context Interdependence

*Identity is NOT the same as Type# Parameters in Gray represent the contexts that May get affected while those in Black represent contexts that Will get affected

The priority order is decided on the basis of three rules:

1. The parameter that definitely affects the most number of parameters has highest priority

2. The parameter that potentially affects other parameters comes next

3. Only the parameters affected by initial parameter change gets affected (i.e. there are no cycles)

Adaptation Rules

The Adaptation Protocol

Implementation

ON/OFF Policies - Policies the upon satisfaction of conditions in its antecedent, can

change device states from ON <-> OFF

ALERT sending policies - Policies that upon satisfaction of conditions in its antecedent,

produce/send an alarm to designated services

Types of Rules Considered

The Architecture

Rule Parser Language Specific

Parsing

Output

User Interaction

Trig

gerin

g C

onte

xt

Target Rule

Contextually Adapted Rule

Extend the Ontology with concept-context relationship Parametrized SPARQL rules (CONSTRUCT queries) Adapted using ARQ (QuerySolutionMap)

- ARQ is a query engine for Jena- A map of variable names to RDFNode objects- Used for dynamic binding of variables to values

Interaction with user asking values for affected variables/parameters

- Present the user with justified ontology* showing explanation of the context

Instantiating the Rule with new values for variables

*A justification for an entailment in an ontology, is a minimal subset of the ontology that is sufficient for the entailment to hold

Implementation Details

School in Austria

Factory floor in Russia

Two Real Smart Building Setups

Smart Building Installation @ School

Several Smart Meters Sensors (e.g. light, temperature,

humidity) Smart plugs, for individual

sockets Rule based shutdown services

for PCs Rule based alarms/alerts User interfaces and apps: Web,

tablet, smartphone (Android)

The Alert Monitoring app

Power Management Service - Tablet

Power Management Service - Smartphone

Evaluations

Policy adaptation - correctness, - automation, - acceptance, etc.

Tools evaluated- Alert Monitoring App- Power Management Services

Evaluation Criterion

Alert Monitoring Policies - Evaluation

App installed in 2 Android based tablets Data collected over ~6 months used to come up with alert

thresholds Underlying system policies were adapted according to

these threshold values Pupils of a class were allowed to share the tablets and

use them for monitoring alerts and set filters themselves Trials were carried out for 1 week

Alert Monitoring Policies - Evaluation

Power Management Service - Evaluation

Android based smartphones and tablets were distributed among pupils and teachers

App was used to monitor and control the power management service installed in 3 of the computer rooms of the school

The app would also allow a user to change the state of the computers in computer rooms from IDLE to AWAKE or OFF.

Tests performed with pupils from two classes for 1 week each (= total 2 weeks) with the tablets and 1 week with the smart phones

Policies were adapted after every week (Phase) of the trial

Power Management Service – Evaluation: Week 1 vs Week 2

Power Management Service – Evaluation: Week 2 vs Week 3

Conclusion

Conclusions

1. How dependent are semantic policies on the contextual conditions for which they have been developed? Various degrees of dependence of policies on various

parameters shown

2. Which context parameters are included in a typical policy? A list of five context parameters identified and studied in details.

“People” as context deliberately excluded from this list

Conclusions

3. How dependent are the context parameters on each other? The inter-dependencies of the listed parameters studied and

explained in details

4. Can a policy be adapted from one contextual setting to another using this knowledge and still solve the purpose for which the policy was originally created? A technique for context based adaptation of semantic policies

was proposed and evaluated for the use case of smart buildings on real users

Thank You for Attention

Reference:

Kumar, V., Fensel, A., Fröhlich, P. “Context Based Adaptation of Semantic Rules in Smart Buildings”. In Proceedings of the 15th ACM International Conference on Information Integration and Web-based Applications & Services (iiWAS2013), ACM, 2-4 December 2013, Vienna, Austria.