History of Context-Aware Comput-ing

• 1991 the term ‘pervasive’ introduced by Weiser • 1992 Active Badge Location System (one of the first context-

aware systems)– User’s location -> forward phone calls to a telephone close to the

user

• 1994 the term ‘context-aware’ introduced by Schilt, Theimer– User’s location, identities of nearby people, objects and changes to

objects

• 1996 Brown’s definition of context– elements of the user’s environment which the computer knows

about

• 1997 Example of Logic based context model: McCarthy and Buvac

• 1997 Ryan’s definition of context– user’s location, environment, identity and time

History of Context-Aware Comput-ing

• 1997 location-aware tour guide by Abowd– Providing information according to user’s current location

• 1998 location-aware tour guide by Sumi– Providing information according to user’s current location

• 1998 Dey’s definition of context– user’s emotional state, focus of attention, location, orientation,

date and time, as well as objects and people in the user’s environment

• 2000 location-aware tour guide by Cheverst– Providing information according to user’s current location

• 2000 Dey and Abowd’s definition of context– “any information that can be used to characterize the situation of

entities between a user and an application, including the user and the application themselves”

– Proposed criteria for a reasonable architectural approach

History of Context-Aware Comput-ing

• 2000 Budzik and Hammond’s Watson Project• 2000 W3C, RDF available• 2000 Location-aware systems: Priyantha• 2001 Location-aware systems: Espinoza• 2001 Dey and Abowd :

– Entities: places, people, things– Attributes: identity, location, status, time– Widgets

• 2001 Finkelstein’s IntelliZap• 2001 Winograd :

– describes three different context management models for conordinating multiple processes and components – Widgets, Networked services, Blackboard model

• 2001 Hong and Landay – Networked services – (resembles the context server architecture)

• 2001 Example of Markup scheme models: User Agent Profile (UAProf)• 2001 Dey and Abowd’s Context Toolkit

– p2p architecture + centralized discoverer, attribute-value tuple/XML - Context aggregation/interpretation, historical context data, Context Ownership (Privacy)

History of Context-Aware Comput-ing

• 2002 Location-aware systems: Burrell and Gay• 2002 Hofer’s Hydrogen

– local/remote context, Object Oriented Model, process higher-level context abstraction in application layer

• 2002 Gustavsen classifies context instances into– External: refers to context that can be measured by

sensors/hardwares– Internel: mostly specified by the user or captured by monitoring

user interaction

• 2002 Hofer classifies context instances into – physical & logical

• 2002 Location-aware systems(indoor): Harter• 2002 Dey and Abowd: Layered conceptual framework for

context-aware systems

History of Context-Aware Comput-ing

• 2002 Roman’s Gaia project – extends operating system contepts to include context-awareness– 4-ary predicates in DAML+OIL, context processing is based on first-order logic

operation

• 2003 Context-aware infrastructure: Munoz (hospital)• 2003 Burnett classifies context instances into external & internel• 2003 Indulska and Sutton classified sensors in three groups

– physical sensors, virtual sensors, logical sensors

• 2003 Example of Graphical Models: Hendricksen’s ORM• 2003 Korpipaa presents requirements and goals of context ontology

– simplicity, flexibility and extensibility, genericity, expressiveness

• 2003 Koripaa’s Context Managing Framework – centered server

• 2003 Chen’s CoBrA(Context Broker Architecture)– intelligent space, Broker federation – Avoiding bottleneck, COBRA-Ont, Inference

Engine, historical context data, Context Knowledge base – you can assert, delete, modify, query the stored data(API), flexibile policy language to control context access called Rei (privacy)

• 2004 W3C, OWL available

History of Context-Aware Comput-ing

• 2004 Location-aware systems: Kerer• 2004 Chen presents three different approaches how to acquire contextual

information– Direct sensor access, Middleware infrastructure, Context Server

• 2004 Example of Markup scheme model– W3C, Composite Capabilities/Preference Profile (CC/PP)

• 2004 Strang and Linnhoff-Popien summarized the relevant context modeling approaches

• 2004 Gu’s SOCAM(Service-Oriented Context-Aware Middleware) – centered server -upper ontology, domain-specific ontology, reasoning engine, historical context data

• 2004 Fahy and Clarke’s CASS – – Inference Engine, historical context data, Context Knowledge base – you can assert, delete, modify,

query the stored data(API)

• 2004 CORTEX– based on sentient object model – sensor fusion to manage uncertainty of sensor data, CLIPS Inference

Engine, historical context data

• 2005 Example of Graphical Models– Context Modeling using UML : Sheng and Benatallah

• 2007 Ejigu’s CoCA• 2008 Ejigu’s Enhanced CoCA

1990

2010

2000

1991

Context Definition

Application & Sys-tem

1992

Context = Location

the term ‘pervasive’ introduced by Weiser

1994

Context Models Logic based context model: McCarthy and Buvac

1997

Active Badge Location System

the term ‘context-aware’ introduced by Schilt, Theimer

Ryan’s context: user’s location, environment, identity and time

1996

location-aware tour guide by Abowd

location-aware tour guide by Sumi

1998

Dey’s context: user’s emotional state, focus of attention, location, orientation, date and time, objects and people in the user’s environment

location-aware tour guide by Cheverst

Dey and Abowd’s context: “any information that can be used to characterize the situation of entities between a user and an application, including the user and the application

Budzik and Hammond’s Watson Project

W3C, RDF available

Location-aware systems: Priyantha

Fundamental & new Ideas

Finkelstein’s IntelliZap

2001

Markup scheme models: User Agent Profile (UAProf)

Dey and Abowd’s Context Toolkit

Hofer’s Hydrogen

2002

Object-Oriented Model

Roman’s Gaia project

Attribute-Value Tuple

DAML+OIL 4-ary predi-cate

Context-aware infrastructure: Munoz (hospital)

Graphical Models: Hendricksen’s ORM

2003

Koripaa’s Context Managing Framework

Chen’s CoBrA(Context Broker Architec-ture)

W3C, OWL available

2004

Markup scheme model: W3C, Compos-ite Capabilities/Preference Profile (CC/PP)

Gu’s SOCAM

Fahy and Clarke’s CASS

CORTEX

Context Modeling using UML : Sheng and Bena-tallah

2005

Ontology-Model

2007

Ejigu’s CoCA

Ejigu’s Enhanced CoCA

2008

P2P Approach Centralized Approach

Context aggregation/interpretation Broker federation Upper ontology, domain-specific ontology

Sentient object model

policy language to control context access Historical context data

1990

2010

2000

1991

Context Definition

Application & Sys-tem

1992

1994

Context Models

1997

1996

1998

Fundamental & new Ideas

2001

2002

2003

2004

2005

2007

2008

Loca-tion

Location, Time, Envi-ronement,

Identity

Location, Time, Environement, Identity, Emo-

tionql Status, Ori-entation, Focus

of Attention

any information that can be used to characterize the situation of

entities between a user and an application

Location-aware system

General Context-Aware System

Context System using More Flexible and Exten-

sible Context Model

Non-Flexible Context Model

GeneralFlexible

Extensible Context Model = Ontology Model

Non Centralized Architecture

Centralized Ar-chitectureSemantic Tech-

nology Intro-duced

Emphasis on Pri-vacy & Sercutiry

Upper Ontology+ Domain Specific

Ontology

Keywords:GeneralityExtensibil-ityFlexibility

Conclusions• Limitations

– None of them has done work on learning from historical context data– Only few systems(Gaia, CoBra, …) have security policies– Virtual and logical sensors are limited– Every system uses its own format to describe context and its

communication mechanism

• To Dos– 성찬이형과 Context Model 연구중 -> 개발 된 Framework 의 Rule Engine 과

Context Model 을 교체– 앞으로의 연구 방향

• 실험 위주의 진행• 실험 후 한계점 극복을 주목적으로 재 설정하고 연구진행

– Survey Paper• History of Context-aware Computing• Past, Present -> Future

• Etc– Reading List