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