Rule-based Context-aware Adaptation Usinga Goal-Oriented Ontology

Hongyuan Wang (Jilin University, China)

Rutvij Mehta (The University of Texas at Dallas,USA)

Sam Supakkul (The University of Texas at Dallas,USA)

Lawrence Chung (The University of Texas at Dallas,USA)

13th ACM International Conference on Ubiquitous ComputingInternational Workshop on Situation, Activity and Goal Awareness

September 18th 2011

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Outline

Introduction

Problem and Solution

An Example Scenario

Our Goal-oriented Rational Approach Solution steps

A SIG representation

Context-Software Relationship in a Context-aware

adaptive environment

A Context-aware Goal-oriented Adaptation Ontology

Implementation

Conclusion and Future Work

Introduction

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Context-aware adaptive application software system should be able to adjust its behavior according to

the changing needs in the environment

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Problem and Solution

Many possible alternatives for an adaptation action by and large have not been considered systematically and rationally.

We propose a goal-oriented approach in which various nonfunctional requirements (or quality attributes) such as safety, cost, and promptness are treated as softgoals to be satisfied and used in exploring, analyzing and selecting among possible adaptation alternatives, in consideration of the particular contextual event.

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An Example Scenario

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How to deal with a safety critical situation

Should only 911 be called? Should only the emergency contact be called? Only an alarm should be raised? Should both 911 and emergency contact be

called? Should an alarm be raised and location of the

elderly sent to the emergency contact? ….. (various other possibilities exist)

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Our approach

Post the non-functional requirements (or quality attributes) such as safety, cost, promptness, etc., relevant to the contextual event as softgoals.

Outline the alternative actions for each soft goal. Analyze these alternatives, with respect to their

tradeoffs, i.e., positive or negative impacts on the NFR softgoals.

Prioritize the quality softgoals throughout the process of disambiguation, operationalization and conflict resolution.

Select the best possible alternative(s).

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A SIG showing some alternatives for adaptation action

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A SIG showing different alternative chosen

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Context-Software Relationship in a Context-aware adaptive environment

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Context-Software Relationship in a Context-aware adaptive environment

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System State Transition Diagram

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Rules

The form of Rules (Software system) Adaptation rules:

• Contextual condition -> Software system action Rules for Context state change:

• Condition & Action->Context’ Rules for Software system state change :

• Condition & Action ->Software system state’

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Rule-based Context-aware Adaptation

Adaptation: Behavior (Software) X Change (Context) X Rules -> Behavior’ (Software)

The change of software behavior can become part of the new context.

The rule for System state transition has two parts: Rule_system_1: Context’->Adaptation Action Rule_system_2: Adaptation action ->Context’’

The example scenario: Rule_system_1: (User fallen down) -> (Switch to emergency, get user

location and dial emergency contact) Rule_system_2: (Switch to emergency, get location and dial

emergency contact) -> (User fallen down) & (Sent location and emergency situation information to contact)

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A Context-aware Goal-oriented Adaptation ONTOLOGY

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Hope software system Hope software system

HOPE (Helping Our People Easily) is a mobile-based solution, currently running on the Android platform (v2.1 or higher), aimed at alleviating the communication and day-to-day difficulties faced by people due to symptoms such as loss of speech, loss of hearing, weak vision, loss of memory and others, chiefly among the senior population.

http://www.utdallas.edu/~rym071000/index.html

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Hope system Screenshot

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Safety Critical (Emergency) Scenario Implementation

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A Safety Scenario SIG

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Analysis of Alternative Actions

Quality Attributes /

Alternatives

Cost! Safety!! Privacy Quietness

Call 911 -- ++ +- +

Call Contact + + + +

Raise Alarm ++ +- + --

Call Contact and Send Location

+ ++ - +

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Alternative Actions and Their Tradeoffs in HOPE

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Conclusion and Future Work

Proposed a goal-oriented approach of context-aware adaptive application Relationship between software and context in system A system state transition diagram and rules A context-aware goal-oriented adaptation ontology a goal-oriented systematic decision process of context-

aware adaptive application Implementation support

HOPE software

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Future Work

To add configuration settings for the user to be able to add/alter rules

To add conditions for safeguarding against undesirable side-effects from user-defined rule changes

To find our context ontology and the transition diagram strengths and limitations.

To detect and deal with rule conflict

Thank you!

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