sensor networking research team context aware technology jae doo huh 2008. 3. 11

Sensor Networking Research Team

Context Aware TechnologyContext Aware Technology

Jae Doo HuhJae Doo Huh

2008. 3. 112008. 3. 11

U-IT Europe Forum 2008 2Sensor Networking Research Team

ContentsContents

I. Introduction

II. Context? Future Computing Ubiquitous Computing Motivation Smart Device

III. Context-aware Computing Context-aware Computing Context – who, where etc.. Context Modeling Service Application

IV. Context-aware Services


I. IntroductionI. Introduction

Paradigm ShiftParadigm Shift Ubiquitous ComputingUbiquitous Computing Future Computing RoadmapFuture Computing Roadmap


Paradigm ShiftParadigm Shift

Computing

46: ENIAC71: 400472: 800873: 8080/8578: 8086/8882: 8028685: 8038689: 80486

Mainframecomputer

Personal Computer

NetworkedComputers

1980s1960s

1990s

Sharing Sharing a a

computecomputerr

Individual Individual usageusage

Sharing Sharing overover

InternetInternet

UbiquitousComputing

2000s

informatioinformationn

everywheeverywherere

93: Pentium95: P-pro97: P-II99: P-III00: P-IV08: P-QuadCore

195019752000

Context-aware ComputingPersonal Computing

Horizontal MarketNetworked Computing

Small, Intelligent, 3DSmall, Intelligent, 3D


The VisionThe Vision

Mark Weiser (1952 – 1999), XEROX PARC

“ In the 21st century the technology revolution will move into the everyday, the small and the invisible…“Mark Weiser, 1988

“The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it”Mark Weiser, 1991


II. Context-awareII. Context-aware

DefinitionDefinition Examples of contextExamples of context Context InformationContext Information


ContextContext

The specific conditions, external to the application itself, such as

audience, speaker (user), situation (place and its surroundings), time,

environmental and network conditions, etc., which determine the

application behavior, will be called the ‘context’ of the application.

+Sensed Context

+Predefined Context

+Inferred/Deduced Context


Context DefinesContext Defines

“Everybody has a different notion.”

Context in the literature: location, identities of nearby people and objects. time of day, season, temperature. user‘s emotional state, focus of attention environment the user and computer know about state of the computer surroundings


Pascoe(1997): taxonomy of context-aware features contextual sensing context adaptation contextual resource discovery contextual augmentation (associating digital data with user’s

context)

Abowd & Dey(2000): context-aware features presentation of information/services to a user according to current

context automatic execution of a service when in a certain context tagging context to information for later retrieval

Kotz: Active context awareness - An application automatically adapts to

discovered context, by changing the application’s behavior Passive context awareness - An application presents the new or

updated context to an interested user or makes the context persistent for the user to retrieve later.

Context-aware?Context-aware?Context-aware?Context-aware?


Shortcomings of the Shortcomings of the formerformer systems systems

Context acquisition and use was often tightly integrated into a single application, and could not easily be incorporated into other applications.

Individual agents are responsible for managing their own context knowledge

Thus application developers often find it very difficult to build their applications

Lacking an adequate representation for context modeling and reasoning Existing solutions for Context information are

Name-value pairs (in the Context Toolkit) or entity relation model Objects to represent context with methods and fields for retrieval of information Simple matching mechanisms for context access, and developers must perform low-leve

l programming for reasoning

Users often have no control over the information that is acquired by the sensors

Privacy Concerns


And the Role of MiddlewareAnd the Role of Middleware

Designating those steps to Middleware will: Free the application developer from underlying tasks: sensing technologies,

gathering sensed context data, modeling context data, reasoning and delivering/disseminating the inferred contexts to applications

Let him focus on implementing application logic Reusability: built once – used by everyone Separation of concerns: Context-aware Middleware decouples application layer

with lower layers => more efficient to develop


Context-aware MiddlewareContext-aware Middleware

Desired Characteristics: Support for heterogeneous and distributed sensing agents

Make it easy to incrementally deploy new sensors and context-aware services in the env.

Provide different kinds of context classification mechanisms -> Flexibility Different mechanisms have different power, expressiveness properties Rules written in different types of logic (first order logic, description logic,

temporal/spatial logic, fuzzy logic, etc.) Machine-learning mechanisms (supervised/unsupervised classifiers)

Follow a formal context model using ontology To enable syntactic and semantic interoperability, and knowledge sharing between

different domains

Facilitate for applications to specify different behaviors in different contexts easily, as well as privacy policy and security mechanism

Graphical development tool to ease developers in writing code.

Dealing with uncertainty to enhance the quality of context


III. Context Aware ComputingIII. Context Aware Computing

Context Aware ComputingContext Aware Computing Context DefineContext Define Context ModelingContext Modeling Application ServiceApplication Service Related WorkRelated Work


Context Aware ComputingContext Aware Computing

Context-aware To recognize user’s state and surroundings, and modify its

behavior based on this information Is

Breaking computers out of the box Making computers more aware of the physical and social

situations they are embedded in One line of ubiquitous computing research

“A Context-aware Systems should make my life easier but if it makes mistakes I’m angry with it and the second time it does something wrong I turn it off (forgetting the many times it was working correctly…)”

They want cellular phones but we don’t want the antennas…


Context Information - LocationContext Information - Location

The Active Badge (92) User based indoor location sensing

Identity using an IR data link Active maps: scalability

@ Olivetti Research Lab (Cambridge, UK)

ParcTabs (Schilit 95) Active badge+wireless: Rough location + ID

Active Bat (Ward 97) Active Badge: only identify 2D location Ultrasonic fine-grained 3D location system


Context Information - LocationContext Information - Location

Cricket (MIT Oxygen): An indoor location system for pervasive comp

uting env. RADAR (Microsoft)

A set of static receivers track positions of transmitters

Barcode 1D vs. 2D & BW vs. color

Load cell (GATECH) vs. ON/OFF cell

Simple ON/OFF switch GIST

GATECH


Context Information – User IdentifyContext Information – User Identify

Who: Biometric sensors

Face recognition): Speech identification/recognition


Context Information - BehaviorContext Information - Behavior

What: User’s behavior Body tracking Gesture recognition Activity recognition Object recognition

Body tracking

Face

Guesture

Environment


Context Information - IntentionContext Information - Intention

How & Why: User’s emotion Sensing affect signals Recognizing patterns of affective expression

lightness, Angry, Fear,,,


IV. Context Aware ServicesIV. Context Aware Services


Context aware Intelligent ServiceContext aware Intelligent Service

Light Sensors

Smart Home

Context-aware Agent


Context aware Intelligent ServiceContext aware Intelligent Service

Smart Home

Health Care Sensors

Context-aware Agent


Q and AQ and A

Discussion and More Information…

Open to Collaborative Research with ETRI

to [email protected]

sensor networking research team context aware technology jae doo huh 2008. 3. 11

Documents

taxonomy of context

updated context

context persistent

certain context

contextaware services

active context awareness

users context abowd

europe forum