context aware.pptx

cloud computing

1. Context - Awareness Submitted by: Nassmah Al-Matari Zahra Rajeh Fatima Al- Hadi Somaia Al- Bahri Sana'a University - Faculty of Computer & IT Master Information Technology 2nd semester Submitted to: Prof. Ammar Zahary   2022  

2. Context is the surrounding environment, location, or situation which determine, specify the meaning of the event. Context is any information that can be used to characterize the situation of an entity” Entity : person, place, object that is considered relevant to interaction between a user & an application, including the user & application themselves. Introduction

3. Context as Implicit Input/Output Con text- Aw are System ex pli c i t input explicit output Context: state of the user state of the physical environment state of the computing system history of user-computer interaction ...

4. C lass i f i c ati o n o f C o nte xt Computing Context: Network connectivity Communication cost Comm. Bandwidth Nearby resources User Context: User profile/preference User mood/ behaviour Other’s presence Environmental Context: Lighting Noise level Traffic conditions Weather Physical Context: Time, Date Location

5. Context Awareness Context awareness is the term that describe the ability of the computer system to sense and act upon the information about its environment such as, Location, Time, Temperature or User Identity. Context Awareness enable the system to take action automatically, and Reducing the burden of the excessive user involvement & provide proactive intelligent assistance.

6. C o n t ex t - A w ar e S y s t e m s A user has left his office The system forwards the call to a nearby phone The system detects his current location Calls are forwarded to his voice mailbox A Call-forwarding System The system detects the user is in a meeting The phone rings in his office

7. User-Related: Context Awareness • Who: Deals with identifying current user and object recognition. • Where: Deals with location identification of user, object, service, … • When: Deals with temporal aspects of past, present & future. • What: Deals with identifying activities of user or object. • Why: Deals with subtle context such as user's need, emotion, …

8. Categories of context awareness Active Context Awareness : Influence the behaviour of the application. Active Context Awareness automatically changes the behaviour of the application according to the Sensed information. Example: Automatically press breaks of car when it sense the obstacle in front of the car.

9. Active Context Awareness :

10. Context that is relevant but not critical. Passive Context Awareness presents updated context or sensor information to the user and lets the user to change th e application behaviour. Example: Reports the position of the moving car into the map. Passive Context Awareness:

11. Pervasive Computing  Pervasive computing also called as Ubiquitous computing.  The word Pervasive or Ubiquitous means: “ Existing Everywhere ”.  Pervasive Computing is the growing trend towards embedded Microprocessor in every day object so, that they can communicate information.

12. Structure & Elements of Context Aware Pervasive Systems A Context-Aware Pervasive System can be viewed as having three basic functionalities: Sensing, Thinking (metaphorically) Acting

13. Sensing What are Sensors ? Biological or Non biological Sensors - to acquire data or information about the physical world or some aspect of the physical world. Multiple Sensors can also be used Treated as input What Info can be sensed ? Types of Sensors

14. Sensors Physical sensors sensor, camera, microphone, accelerometer, GPS, biosensors, etc. Virtual sensors From software: browsing an electronic calendar, a travel booking system, emails, mouse movements, keyboard input, bandwidth, etc . Logical sensors Combination of physical and virtual sensors with additional information (e.g. context history) from databases

15. T h i nk i n g Knowledge about the context or situation of entities . Once the data is obtained using the collection of sensors. The task is to utilize such data and to make sense of it on the basis of definition of sensors.

16. A c t i ng Once context information has been gathered or situations recognized, actions are taken. The actions to be taken are application specific. Actions might need to be performed in time for it to be of use to the users, and before the situation which triggered the action changes. Considerations  Performance.  Control.

17. Abs t ra c t l a y er e d a r c h i t e c t ure f o r C o n t e x t - aware systems:

18. Human to Human communication ➢ Situational information such as facial expressions, ➢ E mo ti o ns, ➢ Voice tone Past and future events, The existence of other people in the room Th e process of building this sha red und er s tanding b et w een two people is called grounding . Need For Context Aware (CA) Computing

19. Human and Computer co m m u ni cation Following Tasks can’t be easily done by Computers : Understanding and Interpreting our language We need to be very specific about giving commands OR asking for information Cannot sense information about the current situation Sensing Facial expression Presence of other people near by. Need For Context Aware (CA) Computing

20. Context, critically required in Ubicomp Environment . M o b i l e c o m puti n g a n d u b i quit o u s c o m putin g h a v e g iv e n u s ers th e e x p e c ta t i o n that they can access whatever information and services they want, whenever they want, and wherever they are. C o nt e x t can b e us ed t o h e l p d eterm in e w h at in f o r m a ti o n o r s er vi ces t o make available or to bring to the forefront for users. The goal of context-aware computing is to use context as an implicit cue to enrich the impoverished interaction from humans to computers, making it easier to interact with computers. Need For Context Aware Computing

21. Context Aware Applications “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.” E.g. Smart Phones screen goes Brighter when exposed to And goes dimmer on low light ( using photo sensors), battery . Some of the context Aware Apps For Android

22. Context Aware Applications A r c hit e ctu r e C o n t e xt Input Co n t e xt A w a r e A pp l ication Explicit Input Explicit Ou t p u t

23. Context Aware Applications Context-aware applications look at the who’s, where’s, when’s, and what’s (i.e., what activities are occurring) of entities and use this information to determine why a situation is occurring. An application does not actually determine why a situation is occurring, but the designer of the application does. The designer uses incoming context to determine the user’s intent, or why a situation is occurring, and uses this to encode some action in the application that helps to satisfy this intent.

24. Properties of Context Aware “Model/Framework” Adapt interfaces ( Context sensing and acquisition ) Increase the precision of information retrieval, Tai l or t h e s e t of a p p l i cat i o n - r elev a n t d ata ( Pr o c e ss i n g , agg r e ga t i on and reasoning of contextual data ) Context modeling, representation and storing, Context-Aware application adaptation,

25. Properties of Context Aware “Model/Framework” Integration of Context-Awareness into Service-Oriented Architectures. Security and privacy of Context data, Discover services 2G , 3G or Wifi connect to best of available. Make the user interaction implicit, or build smar t environments .

26. Issues and Challenges E r r o rs O c cu rr e d be c a u s e o f wr on g inte r pr e t a t i o n of Context : When the system does the wrong thing Auto-locking car doors Screen saver during presentation Microphone amplifying a whisper In these examples, is the system or the user at fault?

27. Issues and Challenges Challenges in Context-Aware Computing – How to represent context internally? (Storage) – Data structures and algorithms – H ow f r eq u en t l y d o es t h e sy s t e m nee d to b e u p d a t ed o n c o n t ex t 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?

28. Issues and Challenges Issues to Consider when Building Context-Aware Applications Context Is a Proxy for Human Intent Context Inferencing i s th e a ct o f ma k in g s e ns e o f th e s e inpu t d a t a f r o m s e ns o rs a n d o t h er s o u r c e s , to determine or infer the user’s situation. Context Ambiguity “Rules” versus “Machine Learning” Privacy Evaluation End User Issues Understanding of Application’s behavior How much control on application user should have

29. Thanks