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Dart: A Meta-Level Object-Oriented Framework for Task-Specific Behavior Modeling by Domain Experts

R. Razavi et al. - 1 -.OOPSLA Workshop DSML‘06

Dart: Dart: A Meta-Level Object-Oriented A Meta-Level Object-Oriented Framework for Task-Specific Framework for Task-Specific

Behavior Modeling by Behavior Modeling by Domain ExpertsDomain Experts

Reza Razavi

University of LuxembourgLUXEMBOURG

[email protected]

Jean-François Perrot

Université Pierre et Marie Curie – CNRS – LIP6, Paris –

[email protected]

Ralph Johnson

University of Illinois at Urbana Champaign,

Illinois – [email protected]



Background Photo: http://pinker.wjh.harvard.edu

Connecting together a large number of small computers with sensing and actuating capabilities, to collectively and cost-effectively solve problems, based on real-time

data.

A Wireless Sensor Network




Query: detect an animal

Query: chart traffic

patterns

Query: photograph

speeding vehicles

Dynamic Macroprogramming of WSNs by End-users (experts)

Requires specifying coordination between tasks

Requires specifying a behavior repeated over

time

Requires specifying correlation of time series of basic sensing data into high-level semantic

data



Requirements summary

• End-users• Expressing

• Relatively easily

• Complex behavior

• DSML Programmer: face diversity of application domains

• Business-specific • Ontologies

• Modeling constructs

• Model execution strategies

• DSML Programmers• Developing DSMLs for different application domains by

• Reuse

• Extension



Task-Specific Behavior Modeling [B.A. Nardi]

Entities and relationships

collection

Mobile Object

Animal

Pulse

Pulse Pair

Classify Animal Estimate Motion

Detect Beam EventSort EdgesAverage Pulse Pairs

Primitive tasks

Behavior

specification

Animal

Classify Animal

2

1

T2: Identify Animal

Mobile Object

Estimate Motion

3

Pulse Pair 3

Average Pulse Pairs

4

Pulse 1

Detect Beam Event

9

Pulse 2

Detect Beam Event

8

Pulse 3

Detect Beam Event

7

Pulse Pair 1

Sort Edges

6

Pulse Pair 2

Sort Edges

5



The Problem

• Method for stepwise development of • Task-specific languages for behavior modeling

• Satisfying both •End-users, and

•Programmers requirements



Dart core concepts

-argument

-holds

-instantiates

-method

Process Conscious Product

Task Part Holder

1 1..*

Construct

1..1

0..1

Contract

Ontology Concept

0..1 0..*

1..1

-spec1..1

1

-dependents0..*

0..1

0..1

Execution Strategy

-policy

1..1 0..*

Behavior

1*

0..*

-contributes 0..*

Design decisions explained and motivated in the paper.



1

Liz’s query

2

Main

3

T1: Compute Histogram Entry

4

T2: Identify Vehicle

Histogram

5

Plot Histogram

Histogram Entry Collection

6

For a Period of <2 weeks> Do <T1>

Mobile Object

Estimate Motion

8

Pulse Pair 3

Average Pulse Pairs

9

Pulse 1

Detect Beam Event

12

Pulse 2

Detect Beam Event

13

Pulse 3

Detect Beam Event

14

Pulse Pair 2

Sort Edges

Pulse Pair 1

Sort Edges

10 11

Vehicle

Classify Vehicle

7

Vehicle

Do <T2>

16

Histogram Entry

Create Histogram Entry

15

Illustration of behavior representation by Dart

Behavior

Task

Step (Part Holder)

Construct

Concept

contributes



Implementation

• Research prototypes• Provides extension hooks

• VisualWorks Smalltalk • Dyctalk

• MiDyctalk

• MetaclassTalk• MxDyctalk

• Squeak and Seaside

• Planned to be released as Open Source software



Reuse example: Developing query engines for WSNs

Uses: Seaside framework

(http://www.seaside.st/)

and Squeak (http://www.squeak.org

/)



Conclusion

StepStep

AdaptAdapt

FetchLoadCode

Adaptation cycle

Operational level

Knowledge level

IntrospectionIntercession

Dynamically-composed behavior

-argument

-holds

-instantiates

-method

Process Conscious Product

Task Part Holder

1 1..*

Construct

1..1

0..1

Contract

Ontology Concept

0..1 0..*

1..1

-spec1..1

1

-dependents0..*

0..1

0..1

Execution Strategy

-policy

1..1 0..*

Behavior

1*

0..*

-contributes 0..*

Dart supports stepwise development of Adaptive Object-Models



Current work

• Reusing Dart to support End-user Macro-programming WSNs

• Dart serves:• Edition (GUI)

• Representation

• Verification

• Optimization

• Security

• Transformation

• Distributed, fine-grained, selective deployment

• Concurrent execution



Thank you for your attention!

Questions?Observations?

Reza [email protected]

Autonomous Systems Group University of Luxembourg

Please visit the Poster Session



Outline of the talk

• Context

• Requirements

• Problem

• Solution

• Conclusion and perspectives



Structure of queries

• Finite directed acyclic graph

• Recursive • Steps may hierarchically point to tasks

• Reflective • Same set of concepts reused to extend the system



Semantics of queries

• Parallel evaluation of contributions

• Limited to their dependencies

• Different execution semantics

• Late • value binding

• method binding

• Comparable to spreadsheets



Role of the knowledge level

• Comprises:• Conceptual ontology• Behavioral ontology • Framework for specifying queries as a composition of

services through mediation of concepts

• Assumptions: • Completeness of the service ontology• Acknowledgeability of the users in the domain covered by

the ontologies• Low-level data, such as the sensor id, may be provided by

users (in the process of being relaxed)

• Keeps track of static and dynamic metadata.



Role of the operational level

• The operational level comprises a set of mobile agents

• The agents:• Are defined dynamically

• Execute concurrently•within the WSN, and

•on a single node

• Based on a formal model of computation• In order to be verifiableActors





EU requirements: example 1

Requires specifying correlation of time series of basic sensing data

into high-level semantic data





EU requirements: example 1

Requires specifying correlation of time series of basic sensing data

into high-level semantic data

Animal

Classify Animal

2

1

T2: Identify Animal

Mobile Object

Estimate Motion

3

Pulse Pair 3

Average Pulse Pairs

4

Pulse 1

Detect Beam Event

9

Pulse 2

Detect Beam Event

8

Pulse 3

Detect Beam Event

7

Pulse Pair 1

Sort Edges

6

Pulse Pair 2

Sort Edges

5

Raw sensor data

Semantic Stream [Zhao

et al.]




Query: chart traffic

patterns

Query: photograph

speeding vehicles

EU requirements: other examples

Requires specifying coordination between tasks

Requires specifying a behavior repeated over

time

background photo: pinker.wjh.harvard

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