Smartness of Pervasive Computing Systems Through Context-Awareness
Arkady Zaslavsky Luleå University of Technology, Sweden
ruSmart’2008, Saint PetersburgRussia, 5 September, 2008
http://www.ltu.se/mailto:[email protected]
Outline
Smart place ??BackgroundContext & context-awarenessContextExplorersContext-awareness projectsCoolcampus
Smart place – what is it ?
It is an entity which is aware of its context and services it can offer, and makes that context & services discoverable to authorised entities, and also adapts to those entities needs and tasks. Discovered context can then be used for reasoning about and inferring of occurring situations. On that basis the system then interacts with users offering them appropriate interfaces. Intelligence or “smartness” of this entity is defined by its functionality.
What’s a smart place/space ?
pervasive computing
The idea that technology is moving beyond the personal computer to everyday devices with embedded technology and connectivity as computing devices become progressively smaller and more powerful. Also called ubiquitous computing, pervasive computing is the result of computer technology advancing at exponential speeds -- a trend toward all man-made and some natural products having hardware and software. Pervasive computing goes beyond the realm of personal computers: it is the idea that almost any device, from clothing to tools to appliances to cars to homes to the human body to your coffee mug, can be imbedded with chips to connect the device to an infinite network of other devices. The goal of pervasive computing, which combines current network technologies with wireless computing, voice recognition, Internet capability and artificial intelligence, is to create an environment where the connectivity of devices is embedded in such a way that the connectivity is unobtrusive and always available
http://www.webopedia.com/TERM/P/pervasive_computing.html
http://www.webopedia.com/TERM/P/embedded_system.htmlhttp://www.webopedia.com/TERM/P/pervasive_computing.html
Ubiquitous computingSuppose that you could get a 0.1€ “computer”.
What would you do with it?Play, Work, Sense, ActuateCommunicate, Compute, AccessSearch for info, Find directionsExtend your perception of the worldTrack content and location
How would you configure it?In a stand alone mode In a fixed networked environmentIn ad-hoc networked environment
Should it be visible?How do you interface with it?How do you power it?
Context
The interrelated conditions in which something exists or occurs (Merriam Webster) The situation within which something exists or happens, and that can help explain it (Cambridge Dictionary)“Any information that can be used to characterize the situation of an entity” (Dey, 1999)The set of environmental states and settings that either determines an application’s behaviour or in which an application event occurs and is interesting to the user” (Chen, Kotz, 2000)
Categories of Context
Computing Context – computing informationNetwork context – networking informationUser Context – user’s informationPhysical Context – environmental informationTime Context – such as time of day, week, monthEtc, etc, etc
Categories of Context (cont’d)
In practice, some contexts are more important than others from a computational perspective:
LocationIdentityActivityTime
Answer the questions of who, what, when and wherePrimary Context TypesForm the basis for determining other contextual information known as Secondary Context Types
Context-Awareness: key ingredient in pervasive systems
Context and situation AwarenessUnderstanding the context and possibly situations of a system, e.g.:
User activity, User LocationSmart Space activity (a meeting, a presentation…)Sentient Building, Tour Guides, Context-aware network management
GoalsEnhance services to usersAutomate systems & reduce obtrusiveness Customize & Personalize applications to users
Pervasive Systems Complex networks of mobile and stationary devicesSensor networksAd hoc networks
What is Context-Aware Computing
Schilit and TheimerSoftware that adapts according to its location of use, the collection of nearby people and objects, as well as changes to those objects over time
First Context-aware researchActive Badge system at Cambridge AT&T Labs (Known as Olivetti at that time)
Other SynonymsAdaptive, Reactive, Responsive, Situated, Context-Sensitive and Environment-Directed
Dey & AbowdA System is context-aware if it uses context to provide relevant information and/or services to the user, where relevance depends on the user’s task
Example Scenario
Elevator
Elevator
Elevator
Staircase
Staircase
Power Box
Urgent Email:
File ~10 MB
SMS☺
“In a Meeting”
downloading…
downloading
Silent Mode
Context-aware pervasive computing
Context-aware computing
Pervasive Computing
• makes systems aware of situations of interest• enhances services to users• automates systems & reduces obtrusiveness • Customizes & Personalizes applications
Systems saturated with sensors and computing devices
Context-aware pervasive systems – an evolution of distributed systems
• User activity, situations, system’s context• Smart Space activity• Sentient Building, Tour Guides, • Context-aware games
• Complex networks of mobile and stationary devices
• Sensor networks• Ad hoc networks
Challenges in context-aware pervasive computing
(due to:)Insufficient data to infer contextInherent inaccuracy of sensorsFreshness of informationContext ambiguityUnknown contextual situationsConflicting or contradicting events
(difficult to:)Update functionalityChange & customize system behaviorBecome cost-efficientDeploy effective communication
Lack of appropriate models and theories
Context Uncertainty
Complexity
Theory
Context-Situation pyramid
Situations
Context
Sensory-originateddata
Agent Injection Service
Load Monitor
Reasoning Engine
Cleaner
KB
Data AssimilatorData AssimilatorData Assimilator
Data InserterData InserterData Inserter
Monitor
Stability Analyser
1. Knowledge Synthesiser
2. Conflict Analyser
3. Context Adapter
4. Verifier
MQ
MQ
SensorSensors
AgentFiltering Agent
Reasoning AgentAgent
Agencies
Event Router
Reasoning Layer
Algorithms Library
ContextExplorers – reasoning about context
Agent communication platform using
publish-subscribe
ContextExplorers
A.Padovitz, A.Zaslavsky & S.W.Loke, B.Burg, C.Bartolini
http://welcome.hp.com/country/au/en/welcome.html
a
bc
21 RR ∩
R1
R2
R3
The Context Spaces model: A multi-dimensional context representation
Modeling situations in smart room- A Meeting- A Presentation- Friday Gathering
1R2R3R
Ri
Cj
Ci
context trajectory
situation space & state
situation-space
context-space dimensions
time
Trajectory of a pervasive system in context
The Context Spaces Model: fundamental concepts
Context:‘Walking’
Location
Acceleration
Heart rate
‘Running’
Location
Acceleration
Heart rate
Respiratory Rate
‘Stationary’
‘Eating lunch’
Location
Acceleration
Heart rate
Time
Noise
Unspecifiedcontext-state
‘In a meeting’
Location
Light
Projector Activity
Time
Multidimensional OO representation of Context Spaces
locationgender activity heart rate velocity…..
activity
heart rate
velocity
location
biking
Dealing with uncertainty: Integration based on Multi-attribute Utility (I)
Consider heuristics which model evidence more comprehensively:
Weights reflect relative importance of context attributes
Each value in the multi-dimensional context state contributes value
Contribution
Contributionfunction
Contribution
Attribute value
Contributionfunction
RegionAttribute value
Region
Attribute value Attribute value
Contribution
Contributionfunction
Contribution
Contributionfunction
Region Region
∑=
n
1iiicwConfidence in situation =
Allowing to define different ways of how a sensed value contributes towards inferring a situation (contribution functions)
Dealing with uncertainty: Integration based on Multi-attribute Utility (II)
Computing the contribution value at run-time
Incorporating sensor inaccuracy into the integration
∑=
∈⋅n
1ii
tii )AaPr(w)
Confidence in situation =
denotes the probability of a sensed value being contained within its respective region
)AaPr( iti ∈)
The greater the likelihood of containment the greater contribution…
• An unreliable/inaccurate sensor contributes less than a reliable/accurate sensor
• Knowledge about the sensor error distribution can affect the integration result
Consequences:
Dealing with uncertainty: Integration based on Multi-attribute Utility (III)
Characterizing the context attribute behavior during inference:
Symmetrically contributing - increases the confidence in a situation taking place if its value is within the corresponding region, and decreases the confidence if it is outside that region
Asymmetrically Contributing - increases the confidence in a situation taking place if its value is within the corresponding region but sensing values outside the accepted region do not decrease the computed confidence
Procedure to support heuristic:(1) Assign weights of asymmetric attributes that are not contained in their respective regions to zero(2) Re-compute the weights of the remaining context attributes to maintain their relative importance
Example: Objective – infer “user in a meeting”User left his/her PDA in office but is still in a meeting in the smart room. Therefore: “PDA location” is asymmetric contributing context attribute.
Extending NCS model - ConSpaF
Issues:Individual significance and contribution of context attributes in the situation space ?Inaccuracies of sensory originated information ?Characteristics of context attributes and their effect on reasoning ? Partial and complete containment of context-attributes’ values in the situation space ?
ConSpaF functions
Matching functioncomputes degree of confidence in the existence of a situation
Inference functionIs situation occuring ?
Relevance functionassociates weights with regions of values
Contribution (utility value) functionreflects how well an element is associated with the modelled situation
What is the confidence that all sensed values of the chosen context-attributes correspond to the situation space?
Reasoning concepts
Bayesian approach - assigning probability measures modelling the probabilistic relationships between context-attributes and situation spaces provides an alternative to the heuristicsAn alternative method is Dempster’s rule of integration based on Dempster-Shafer theory which allows assignment of probabilities to uncertain events and offers a way to represent ignorance or uncertainty. In our case, these propositions are the possible inferred situations known to the system and can also include unknown possible situations.Context Spaces provides an approach to purposefully model and reason about the occurrences of situations with limited available information.
NCS algebra
The Context Spaces Algebra is defined over the set of situation spaces.
Operators that capture relationships between situation spacesOperators that produce combinations of situation spaces
Integration operation (restricted union)
Relations over CS
Containment relationshipEqui-Containment relationshipPartial Containment relationshipOverlap relationshipOrthogonal relationship
• Analyze context trajectory
• Predict instability in different dimensions
• Affect the trajectory (stabilize state in given context and space)
Model Implications – Stability in context
Context state trajectory, ideal state in context and tolerable fluctuation regions for that context
Assessing the context stability in tolerable fluctuation regions
Transition to C
Transition to B
Space A
Space B
Space C
Transition areas between context spaces
Reasoning about activities in smart room
Motes Interface Service
Positioning Engine
Hook user activity
Identify presentationact.
Data Fusion
Data Interpretation
Data Interpretation
Positioning Engine
Notebook Location
Motes sensorsNotebook Inferred Location
deployment
sensors layout
Sensor technology used
Ekahau Positioning Engine:
Berkeley Motes:
In Summary
A reasoning approach for evaluating logical expressions about situations under uncertainty, inferring the validity of complex situation expressions A Context Spaces Algebra based on the Context Spaces model, providing operations that manipulate and determine relationships between concepts of the model Implementation of concepts and reasoning approaches
The ECORA framework for context-aware computingThe CORE context-oriented reasoning engineDesign and implementation of an architectural approach to deploy context-aware mobile software agents in pervasive computing systems Design, implementation and evaluation of a solution to the problem of content-based publish-subscribe communication between mobile agents
Demohttp://www.csse.monash.edu.au/~azaslavs/contextexplorers
http://www.csse.monash.edu.au/~azaslavs/contextexplorers
Context Spaces: Extending & Continuing
Context Spaces
Fuzzy sets based extensions Context
discovery extensions
Context based personalization
CS applicabilityin application domains
CS based adaptive data streams
MemoryLane’s Mission & Objectives
Luleå University of Technology
MemoryLane
Create regional growth in
e-health services for elderly people
Strengthen CDH collaboration
with industry, university,
municipalities, healthcare
Research-based products
for people with mild dementia
MemoryLane is co-funded by the European Regional Development Fund (Mål-2)
Create and validate with users a
tool for capturing the life of people
with mild dementia
Build regional industrial network
for participating in commercial exploitation
of results from FP6 COGKNOW.
Luleå University of Technology
MemoryLane
Where have I been yesterday?
Whom I met there?
When was the last time that I
went to the Doctor?
When was the last time that I
met Jim?
Where was that meeting?
What did I do
Today?
What I have to do
Tomorrow?
Images, audio, and videos will
be available for each activity (visit, meeting, etc)
to help the elderly person in recalling what
happen during the activity
MemoryLane’s Main Functions (Demo)
MemoryLane is co-funded by the European Regional Development Fund (Mål-2)
MemoryLane’s System Architecture
Luleå University of Technology MemoryLane is co-funded by the European Regional Development Fund (Mål-2)
MemoryLane’s Mobile Inteface (Demo)
Luleå University of Technology
Who? Where?
Start activity assistance
and navigation to Home
Detect Nearby people
and display the known
people in the system
Show details about
next activityDisplay the activities
of today, yesterday,
and tomorrow
Detect the current location
and Display the known
places in the system
Help
Activities
MemoryLane is co-funded by the European Regional Development Fund (Mål-2)
Mobile Healthcare Applications
a convenient, safe and constant way to monitor vital signs early detection of abnormalities automatic generation of alarms and notifications to healthcare facilities and professionals providing patients with awareness and management of their diseases
low cost of biosensors + innovations of mobile network technologies = encouraging development of mobile Healthcare systems
Mobile HealthCare Projects
Larger scale such as European projects of EPI-MEDIC (Rubel et al. 2005) and MobileHealth (Konstantas et al. 2007)Personal Health Monitoring System (Leijidekkers et al. 2006a, 2006b, 2007)
University of Technology SydneyUsing Awareness project for mobile healthcare focusing on context-awareness (Mei et al. 2007)ambient intelligence technology for home care systems called as AHCS (Ambient Intelligent based Home Care Systems) (Becker et al. 2006)a role-based intelligent mobile care system with alert mechanism in chronic care environment (Lee et al. 2006, 2007)combining an information infrastructure called hyperdatabase and data stream management in a peer-to-peer fashion for healthcare (Brettlecker et al. 2004)Stream query processing for healthcare bio-sensor applications (Chen et al. 2004)
Bio-sensors:Alive Technology (QLD)
Alive Diabetes Management System:-Bluetooth enabled-$550
Alive Heart Monitor +Accelerometer +AliveECG (software)as a package:-Bluetooth enabled-$1200
A & D Medical (VIC)
•UA-767PBT model-Bluetooth enabled-uses the oscillometric method-price $379 -accuracy - ±3mmHg or 2% whichever is greater (pressure) ±5% (pulse)-Measurement range - 20-280mmHg (pressure) 40-200 pulse/minute (pulse)-Validation -Clinically Validated with a AA rating in accordance to British Hypertension Society and AAMI protocols.
Vitaphone - Professional Telemedicine Solutions
Vitaphone Tele-Care-Monitor 3370Blood pressure monitor Bluetooth enabled
Vitaphone Tele-ECG-Loop-Recorder 3100 BT Vitaphone Tele-ECG-Loop-Recorder 3300 BT
ActiveECG
ActiveECG with BluetoothIncludes the ActiveECG hardware, a Bluetooth adapter, software for Palm OS and companion software for the PC, ECG leadwires, battery, test cable, extra cover, and one set of ECG electrodes. US$899
Limitations of Current Systems
context-awareness:the need for a general and formal context modelling and reasoning approachSituations as a higher level of abstraction over context
context: room temp, blood pressure and heart ratesituations: ‘healthy’ and ‘hypertension’
Learning: data stream mining on mobile devicesthe need for light weight algorithmsthe need for context-aware adaptation of algorithms
Situation-Aware Processing (SAP) of Data Streams provides situation-awareness
by integrating fuzzy logic principles into the Context Spaces (CS) model (Padovitz et al. 2006)
provides adaptation of parameters of data stream processing based on occurring situations
Using Light Weight Algorithms (Gaber et al. 2003, 2004, 2005) for data mining
The architecture of SAP
Uses of SAP
running SAAP
can be also used to generate different types of alarms
Situation-Awareness
Benefits:provides a better description and abstraction of patient’s health
there is no need to go through every context details individually and quantitatively
can represent fuzzy and vague situations
such as almost healthy but moving towards hypertension
Adaptation
Benefits:When situations show health problems, based on the type of situation and its degree of criticality, data stream programming parameters are adjustedExample:
If the situation becomes ‘hypertension’, the reading rate of data mining program is automatically increased in order to read data faster and monitor patient closely but when the situation is normal the reading rate parameter is decreased and tuned back to its set value
Demo
LTU-Monash collaboration – PhD-polis
LULEÅTEKNISKA
UNIVERSITET Adaptive & Context-aware Multimedia in ad-hoc communities
Kåre Synnes
Christer Åhlund
Arkady Zaslavsky
Robert Brannström – multiple gateway
connectivity
Ruwini Kodikara –Networking issues, cross-layer context
exchange
Arkady Zaslavsky
http://www.monash.edu.au/
Mulle – EIS plattform
• Minimal ultra-light little EIS• 22x25x10 mm, including power• Power life time months• Full EIS sensor network functionality
TCP/IPAd-hoc networkingSSH securityService discoveryReal time support
CADAMULE
Context Aware Mobile ObjectsMassive amount of sensor dataEfficient Contextaware Data Collection Approach
Mobile Robot (CAM- R)
Mulle Sensor NodeSink
SoundHunters: Mobile Agents Using Sound
Track a moving sound source by listening to the sounds it emits and migrate through the network in order to always stay close to it, at least a step aheadGrasshopper, IBM ViaVoice, Speech Recognition, Sound FilesMedia attention !!!
X
X
X
(a) (b)
(c) (d)
Node with an agentNode without an agentA removed agentDirection of a copySound source
Key
X
Context Service
The architecture of a context service
RA-UDM System
Current projects
Mobile transactions and web-services – Sunam Pradhan (ARC Linkage with RMIT)ARC Linkage with Intel – pervasive computing & crisis medicineARC RN EII – taskforce on context-awarenessRobocollectors in sensor networks – Prem Jayaraman – with LTU, SwedenData stream mining visualisation – Brett GillickIntelligent Transportation Systems - Intersection Collision Detection and Warning, Accident Prevention at Curves, Real-Time Detection of Drunk Driving Behaviour (with CARRS-Q @QUT and Insurance Australia Group)Sensor Networks – Context-Awareness and In-Network Mining for Energy Conservation in Sensor Networks (with Department of Primary Industries, Victoria)
Current projects
Context-aware mobile real-time decision support for contingency management – multidisciplinary teamContext-based adaptation of data streams – Pari DelirReconfigurable software agents – Kutila GunasekeraContext-aware recommender system – Yong Bin KangITS & context-awareness – Waskitho WibisonoDevice ecologyContext-aware web-servicesMutual Awareness for Context-Aware SystemsMobile databases with context-awareness
CoolCampus Ideology
Pervasive/Ubiquitous/Mobile Research•Location awareness•Sensor networks•Adaptability•Context management•Resource constraints•Devices & services•Software•….
University users•Administration•Library•Student services•Academic board•IT Services•Community sector•Monash International•…..
QUESTIONS ?
The End
Smartness of Pervasive Computing Systems Through Context-AwarenessOutlineSmart place – what is it ?What’s a smart place/space ?pervasive computing Ubiquitous computingContextCategories of ContextCategories of Context (cont’d)Context-Awareness: key ingredient in pervasive systemsWhat is Context-Aware ComputingExample ScenarioContext-aware pervasive computingChallenges in context-aware pervasive computingContext-Situation pyramidContextExplorers – reasoning about contextThe Context Spaces model: A multi-dimensional context representationThe Context Spaces Model: fundamental conceptsMultidimensional OO representation of Context SpacesDealing with uncertainty: Integration based on Multi-attribute Utility (I)Dealing with uncertainty: Integration based on Multi-attribute Utility (II)Dealing with uncertainty: Integration based on Multi-attribute Utility (III)Extending NCS model - ConSpaFConSpaF functionsReasoning conceptsNCS algebraRelations over CSModel Implications – Stability in contextAssessing the context stability in tolerable fluctuation regionsReasoning about activities in smart roomSensor technology usedIn SummaryDemoContext Spaces: Extending & Continuing MemoryLane’s Mission & ObjectivesSlide Number 36MemoryLane’s System ArchitectureMemoryLane’s Mobile Inteface (Demo)Mobile Healthcare ApplicationsMobile HealthCare ProjectsBio-sensors:�Alive Technology (QLD)A & D Medical (VIC)Vitaphone - Professional Telemedicine Solutions ActiveECGLimitations of Current SystemsSituation-Aware Processing (SAP) of Data Streams The architecture of SAPUses of SAP Situation-AwarenessAdaptation DemoLTU-Monash collaboration – PhD-polisMulle – EIS plattformCADAMULESlide Number 55SoundHunters: Mobile Agents Using SoundContext ServiceRA-UDM SystemCurrent projectsCurrent projectsCoolCampus IdeologyQUESTIONS ?
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