smartness of pervasive computing systems through context ... · ¾it is an entity which is aware of...

Smartness of Pervasive Computing Systems Through Context-Awareness

Arkady Zaslavsky Luleå University of Technology, Sweden

[email protected]

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


RegionAttribute value

Region

Attribute value Attribute value

Contribution


Contribution


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.


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’s System Architecture

Luleå University of Technology MemoryLane is co-funded by the European Regional Development Fund (Mål-2)

MemoryLane’s Mobile Inteface (Demo)


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


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

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 ?

smartness of pervasive computing systems through context ... · ¾it is an entity which is aware of...

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