pervasive computing 通訊所 693430028 鄭筱親. outline introduction context awareness recent...
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Introduction (1)
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
Introduction (2)
普及計算 == 無間計算 時無間 -----anytime 空無間 -----anywhere 罪器無間 ---any devices 平等無間 ---any race 生死無間 ---service forever
Taxonomy of computer systems research problems in pervasive computing
Remote communicationFault toleranceHigh availabilityRemote information accessDistributed security
Mobile networkingMobile information accessAdaptive applicationsEnergy-aware systemsLocation sensitivity
Distributedsystems
Mobilecomputing
Pervasivecomputing
Smart spacesInvisibilityLocalized scalabilityContext-awareness
Federated communitiesVirtualizationStandardizationUneven condition Grid
computingGlobal
Smart Space
Four Additional Research Thrusts
Effective Use of Smart Spaces Invisibility Localized Scalability Masking Uneven Conditioning
Pervasive Computing : Vision and ChallengesPersonal Communications, IEEE, Vol. 8 , Issue: 4 , Aug. 2001, p.10 - 17
Context-Awareness
What is context? Context is any information that can be
used to characterize the situation of an entity.
An entity is a person, place, or object that is considered relevant to the interaction between a user and an application, including the user and applications themselves.
Towards a Better Understanding of Context and Context-AwarenessGVU Technical Report GIT-GVU-99-22, College of Computing, Georgia Institute of Technology
Context-Awareness Context-aware applications look at the who’s,
where’s, when’s and what’s of entities and use this information to determine why the situation is occurring.
There are four primary types of context Location Identity Activity Time
Towards a Better Understanding of Context and Context-AwarenessGVU Technical Report GIT-GVU-99-22, College of Computing, Georgia Institute of Technology
Issues of implementing a context-aware system
How is context represented internally? How is this information combined with system and
application state? Where is context stored? What are the relevant data structures and algorithms? How frequently does context information have to be
consulted? What is the overhead of taking context into account? What techniques can one use to keep this overhead low?
Issues of implementing a context-aware system What are the minimal services an environment needs
to provide to make context awareness feasible? What are reasonable fallback positions if an
environment does not provide such services? Is historical context useful? What are the relative merits of different location-
sensing technologies? Under what circumstances should one be used in
preference to another? Should location information be treated just like any
other context information, or should it be handled differently?
AHRI
Purpose: Design for people Background: Georgia Tech Broadband
Institute Residential Laboratory a three-story, 5040-square-foot home
that functions a living laboratory for interdisciplinary
design, development and evaluation.
System Architecture
Video
Locations
Camera 1(Fixed)
Camera 2(Fixed)
ColorTracking
ColorTracking
MotionTracking
MotionTracking
Calibrated
Video
Camera 3(PTZ)
Camera 4(PTZ)
ColorTracking
BeamFormer
FaceTracking
AuditoryLocalization
FaceTracking
Video
Video
More Sensors More Sensors
RoomManager
FaceRecog.
Illinois Institute of Technology The application would run on PDAs or Tablet P
Cs Provide users with general campus information
while guiding the user around the campus Maintain continually awareness of the user’s c
urrent location and intent, thereby adapting the tour to the user’s own personal preferences and context.
Hawk Tour—A Context-aware Visitor Guide
Specific of Hawk Tour
Hawk Tour uses the Ekahau Positioning Engine which makes use of the received signal stren
gths from WiFi access points to determine positions of the user
Use 「 Scarlet 」 to collect and provide context information
Scarlet—A framework for context-aware computing Separate infrastructure functionality with
application-specific functionality
Non Functional Requirements Scalability Modularity Cross platform Security Extensibility Ability to Evolve Quality of Service Fault Tolerance Mobility User Friendly Interface
Functional Requirements Context collection Context
Storage/Management Context
Subscription/Delivery Context
Analysis/Composition Ability