mobile computing at acadia university
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Mobile Computing at Acadia University
Tomasz Müldner
Jodrey School of Computer Science
Acadia University, Nova Scotia, Canada
October 13, 1998
Contents
• Electronic campus at Acadia University• Related software projects:
– Automated Courseware Management Environment– Shared Workspace– Distributed Marking System– Jersey
• Other related commercial software• Mobile agents vision
Contents
• Electronic campus at Acadia University• Related software projects:
– Automated Courseware Management Environment– Shared Workspace– Distributed Marking System– Jersey
• Other related commercial software• Mobile agents vision
Acadia University:Overview
• Acadia University was born in 1838
• It is small (< 4,000 students)
• Concentrates on undergraduate programs
• In 1996, partnership with IBM formed
• All faculty members and students get an IBM laptop
Acadia University:Electronic Classrooms
• All classrooms will have:– instructor’s console– network connection for every
student
• Two kinds of classrooms: lecture and studio
Contents
• Electronic campus at Acadia University• Related software projects:
– Automated Courseware Management Environment– Shared Workspace– Distributed Marking System– Jersey
• Other related commercial software• Mobile agents vision
Related Software:ACME
ACME (AITT) provides a single place for:– course-related information:
course outline office hours
– discussion groups– on line testing– upload and download of notes
Related Software:Implementation of ACME
• Server-based, CGI scripts written in Perl
• Dynamic HTML pages
• JavaScript for visual enhancements
• Standard file system for persistence
Related Software:Discussion of ACME
• Popular: used in many courses
• Does not require any installation (Web browser)
• Tends to overload a Web server
• Support for pull, no support for push
• Does not provide collaborative facilities
• Does not automate various tasks
• No support for disconnected operations
Contents
• Electronic campus at Acadia University• Related software projects:
– Automated Courseware Management Environment– Shared Workspace– Distributed Marking System– Jersey
• Other related commercial software• Mobile agents vision
Related Software:Shared Workspace, SW
Provides support for:
• asynchronous exchange of information
• synchronous collaboration in electronic (virtual) classrooms
Related Software:SW: Exchange of Information
• Asynchronous sharing of homogenous, centralized information systems, IS
• Each IS consists of classifications and information
• Every SW can fetch and provide
Related Software:SW: Collaboration
• Support for collaborative editing with a single controller and multiple ghosts
• Various floor control policies
• Chat room for “raising a hand”
Related Software:SW: Implementation
• Every SW is a server and a client
• Client/Server implementation using Java and RMI
• JSDT implementation of shared editing
Related Software:SW: Discussion
• Limited support for collaborative editing
• Inefficient updates of ghosts
• No support for filtering, locating, automatic organization, or alerting
• Each IS is centralized rather than distributed
• No support for disconnected operations
Contents
• Electronic campus at Acadia University• Related software projects:
– Automated Courseware Management Environment– Shared Workspace– Distributed Marking System– Jersey
• Other related commercial software• Mobile agents vision
Related Software: DMS Functionality
• Electronic maintenance of assignments
• Management of distributed information resources:– assignment descriptions– assignment solutions– marks
Related Software: DMS Functionality
• Instructor submits assignment descriptions
• Student downloads assignments and uploads solutions
• Marker downloads solutions, and marks them off-line using specialized marking software; then uploads results
• Student gets a notification
Related Software: DMS Implementation
• DMS consists of a central server and set of “users”: Students, Markers, Instructors
• A user may need to download its application and run it locally. DMS will package the application and deploy it to the user
Related Software: DMS Implementation
•Shared resources and the software that controls access to them resides at a server site
•Java and CORBA are used (for language independence and speed)
•Java Applets are used for the user-side client (for (re)deployment)
Related Software: DMS Discussion
• Centralized server creates a bottleneck
• Very limited support for push
• For marking each assignment, a marker has to develop an ad-hoc marking strategy
Contents
• Electronic campus at Acadia University• Related software projects:
– Automated Courseware Management Environment– Shared Workspace– Distributed Marking System– Jersey
• Other related commercial software• Mobile agents vision
Related Software:Jersey (Tomek, Giles, Nicholl)
MOO/MUD (Multi-User-Dialogs) based systems real world emulation (spatial)
–Users, places, objects–Navigation, communication–Creating, modifying, transporting objects–Run-time customizability, expendability
Related Software:Jersey: Implementation
• Client/server written in VisualAge Smalltalk• Communication with the user by Smalltalk messages (extended with the list of messages)• “Agents” used to automate user queries, automatically capture events, etc.
Related Software:Jersey: Discussion
• Spatial rather than functional organization• Traditional client/server• Agents are really daemons
Contents
• Electronic campus at Acadia University• Related software projects:
– Automated Courseware Management Environment– Shared Workspace– Distributed Marking System– Jersey
• Other related commercial software• Mobile agents vision
Contents
• Electronic campus at Acadia University• Related software projects:
– Automated Courseware Management Environment– Shared Workspace– Distributed Marking System– Jersey
• Other related commercial software• Mobile agents vision
Mobile Agent Vision
“...There is a growing danger that agents will be a deception and an empty promise...”
Benn Schneiderman
Mobile Agent Vision
“...agent technologies are most useful when presenting a simpler abstraction of the environment to the user…”
Cybenko and Brewington
Mobile Agent Vision:Justification
• Rapid (re)deployment of applications
• Automated work
• Ability to find and filter information
• Support for push
• Customized views of information
• Support for disconnected operations
• Active network load balancing
Mobile Agent Vision:Student Registration
Assumptions:– Student registers in five courses– When arrives, receives a laptop– Upon first connection to the network, five
course agents arrive at her/his laptop
Mobile Agent VisionCourse Agent
• Each course agent represents a single course
• The user interacts with the course agent through an activity-based user interface
• Standardized interfaces can be customized (through wizards or an agent shell)
Mobile Agent VisionActivity-based Interface
Translators Agent
Contact Instructor
Read Notes
Get Marks
Mobile Agent VisionActivity-based Interface
Translators Agent
Contact Instructor
Do Assignment 1
Read Notes
Get Marks
Mobile Agent VisionDiscussion
• Agent bureaucracy provides a functional organization (course related agents, etc.)
• Agents come built-in; can be further customized (explicitly, or implicitly: adaptive agents)
Mobile Agent VisionCollaborative Work
• Two modes of operation:– serial; here the agent moves to the next group
member and brings updates.
Group members may be on- or off-line
Mobile Agent VisionCollaborative Work
• Concurrent: two modes of reintegration of data:
merging versioning
Mobile Agent VisionOn Line Testing
• A test agent can be broadcast to the test group
• Each test agent can control the test, mark it, and then store results somewhere
• The test agent may be “customized” to remember past inputs, etc.
Mobile Agent VisionDiscussion Groups
• Two kinds:– off-line (traditional); for push (Informant)– on-line (chat rooms). You can create an agent to
be your proxy in a chat room
Mobile Agent Vision:Distributed Information Systems
(Work in progress: D. Currie)
• Each IS can be distributed (DIS)
• Each DIS is a directed graph; leaves store information, other nodes classification
• Remote information nodes are kept in cache
• Cache is cleared based on priorities
Mobile Agent Vision:DIS
• Cached items can be marked bad
• Multiple views of the classification can be maintained
• Classification can be built explicitly or implicitly
Mobile Agent Vision:DIS + Agents
• Agents can maintain priorities
• Agents can find and filter information so that it is copied into cache and available off-line
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