In this presentation, I describe the Context-Aware concept, Context-Aware Computing, and Context-Aware application with some application example of use it

1. CONTEXT - AWARE
2017 / 5 / 10

2. isapanah.com
@sadra_amlashi
@Amlashi
Sadra
Isapanah Amlashi

3. 1st GENERATION OF
COMPUTING
Some engineering needed to work with just one computer

4. 2nd GENERATION OF COMPUTING
Every person has his/her own personal computer

5. 3rd GENERATION OF COMPUTING
Every person has access to various devices

6. in 3rd generation we believe:
Instead of we drowned in the virtual world,
computers came to our real lives!

7. we call 3rd generation
Ubiquitous computing
( or Ubicomp )
Computing anytime at anywhere

8. Context
The word context is derived from the Latin “contextus”,
which means
“connection of words, coherence,”
and from contexere “to weave together.”
The interrelated conditions in which something exists or
occurs : environment, setting
merriam-webster

9. Context (in papers)
Schilit and Theimer (1994) refer to context as location, identities of nearby people
and objects, and changes to those objects.
In a similar definition, Brown et al. (1997) define context as location, identities of the
people around the user, the time of day, season, temperature, etc
Dey (1998) enumerated context as the user’s emotional state, focus of attention,
location and orientation, date and time, and objects and people in the user’s
environment.

10. 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 the application
themselves.
Dey and Abowd, 2000

11. Light
Time
Location
IdentityTemperature
Social Network
Example of Context

12. Context helps us to do things better
Context influences how we perceive information.
Context enables us to manage the vast amount of information that
surrounds us.
Context allows to discriminate “what is important” and “what is not”.
Context helps us to adapt to our surroundings.

13. Context Categorization
Computing context: For example, network connectivity, communication
bandwidth, nearby resources like printers, displays;
User context: For example, user’s profile, location, emotional state, people
nearby, current activity;
Physical context: For example, lighting, noise level, traffic conditions,
temperature
Some of researchers consider TIME Context as another category. (time of the
day , month , year )

14. Divided Into Two Main Group
Primary Context :
More important than others, e.g. location (where),
identity (who), time (when), and activity (what)
Context Categorization
Secondary Context :
Which can derived from primary constraints, e.g.
Distances, Relationships

15. Applications that use context, whether on a desktop or in
a mobile or ubiquitous computing environment, are called
context-aware.
Context Awareness
In fact, it is the Computer that can both sense, and react
based on their environment.

16. A system is context-aware if it uses context to provide
relevant information and/or services to the user, where
relevancy depends on the user’s task.
Context Awareness
Dey and Abowd (2000)

17. Context-aware applications look at the
• who’s
• where’s
• when’s
• what’s (i.e., what activities are occurring)
of entities and use this information to determine why a
situation is occurring.
Context Awareness Application

18. E.g. Smart Phones screen goes Brighter when exposed
to light ( using photo sensors), And goes dimmer on low
battery.

19. “software that examines and reacts to an individual’s
changing context.”
“...aware of its user’s state and surroundings, and help to
adapt its behavior ”
Context Awareness Computing
Schilit, Adams, & Want (1994)

20. Proximate selection
Automatic contextual reconfiguration
Contextual information and commands
Context-triggered actions
Categorization of features CA Applications
Based on whether the task is to obtain information or to
execute a command, and whether the task is executed
manually or automatically, divided into 4 category:
Schilit, Adams, & Want (1994)

21. Uses the following ways to locate exact position on
• Earth – Global Positioning System
• Tower Signal INFO
• IP address, If wifi connected
• Digital Compass Signal To show the direction
Example (Google Latitude)
Context
• Location
• Time
Issue
It also shows your Friends location on map, if they are using same application and
sharing location

22. Example (Google Latitude)
Application Can be written on
top of this, like:
Location Based Alarm
Near Friend Notifier

23. Example (Bump)
Context
• Vibration/motionsensor
• Location detectors (for verification)
• Time (is most important)
Issue
Bump makes sharing (Photos, Contacts, apps) with people as simple as bumping two
phones together.

24. Issues and Challenges in
Context-Aware Computing
How to represent context internally? (Storage)
Data structures and algorithms
How frequently does the system need to be updated on context changes?
How often to poll? ( in case limited power )
How often to change behavior?
What sensors infrastructure, or sensors are necessary?
What is the fallback condition?
How to sense location information?

25. And ...