History of Context-Aware Computing 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 Computing 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 Computing 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 Computing 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 Computing 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 Computing 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

Context Definition Application & System 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 predicate Context-aware infrastructure: Munoz (hospital) Graphical Models: Hendricksen’s ORM 2003 Koripaa’s Context Managing Framework Chen’s CoBrA(Context Broker Architecture) W3C, OWL available 2004 Markup scheme model: W3C, Composite Capabilities/Preference Profile (CC/PP) Gu’s SOCAM Fahy and Clarke’s CASS CORTEX Context Modeling using UML : Sheng and Benatallah 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

Context Definition Application & System Context Models Fundamental & new Ideas Location Location, Time, Environement, Identity Location, Time, Environement, Identity, Emotionql Status, Orientation, 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 Extensible Context Model Non-Flexible Context Model General Flexible Extensible Context Model = Ontology Model General Flexible Extensible Context Model = Ontology Model Non Centralized Architecture Centralized Architecture Semantic Technology Introduced Emphasis on Privacy & Sercutiry Upper Ontology + Domain Specific Ontology Upper Ontology + Domain Specific Ontology Keywords: Generality Extensibility Flexibility

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