Context Aware Technology

1. Context Aware Technology Jae Doo Huh 2008. 3. 11

2. Contents 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

3. I. Introduction Paradigm Shift Ubiquitous Computing Future Computing Roadmap

4. 1950 1975 2000 Personal Computing Horizontal Market Networked Computing Context-aware Computing Paradigm Shift • Computing Mainframe computer Personal Computer 1990s Networked Computers Ubiquitous Computing 1960s 1980s 2000s Sharing a computer Individual usage Sharing over Internet information everywhere Small, Intelligent, 3D 46: ENIAC 71: 4004 72: 8008 73: 8080/85 78: 8086/88 82: 80286 85: 80386 89: 80486 93: Pentium 95: P-pro 97: P-II 99: P-III 00: P-IV 08: P-QuadCore

5. The Vision “In the 21st century thetechnology revolution willmove into the everyday, thesmall 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 Mark Weiser (1952 – 1999), XEROX PARC

6. II. Context-aware Definition Examples of context Context Information

7. Context • 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

8. Context 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

9. Context-aware? • 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.

10. Shortcomings of the former 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-level programming for reasoning • Users often have no control over the information that is acquired by the sensors • Privacy Concerns

11. And 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

12. Context-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

13. III. Context Aware Computing Context Aware Computing Context Define Context Modeling Application Service Related Work

14. Context 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…

15. Context 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

16. Simple ON/OFF switch Context Information - Location • Cricket (MIT Oxygen): • An indoor location system for pervasive computing 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 GATECH GIST

17. Context Information – User Identify • Who: • Biometric sensors • Face recognition): • Speech identification/recognition

18. Context Information - Behavior • What: User’s behavior • Body tracking • Gesture recognition • Activity recognition • Object recognition Body tracking Environment Face Guesture

19. Context Information - Intention • How & Why: User’s emotion • Sensing affect signals • Recognizing patterns of affective expression • lightness, Angry, Fear,,,

20. IV. Context Aware Services

21. Light Sensors Context aware Intelligent Service Context-aware Agent Smart Home

22. Health Care Sensors Context aware Intelligent Service Context-aware Agent Smart Home

23. Q and A • Discussion and More Information… • Open to Collaborative Research with ETRI to jdhuh@etri.re.kr