MADE Mobile Agents based system for Distance Evaluation
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Transcript of MADE Mobile Agents based system for Distance Evaluation
MADEMobile Agents based system for Distance Evaluation
Vikram Jamwal
99329009
KReSIT, IIT Bombay
Guide : Prof. Sridhar Iyer
ContentsContents
• The application– Motivation
– Domain
– Existing Schemes
• Distributed system structuring– Prevailing paradigms
– Mobile agent approach
• Mobile agent frameworks• Our model• Experimentation• Conclusions
Distance EvaluationDistance Evaluation
• Emergence of distance education– Need for distance evaluation mechanisms
• Alternatives to paper-based exams– Computer based and Internet based
• Scheduled and uniform exams
Types of e-testing mechanismsTypes of e-testing mechanisms
• Where does the database reside?• Locally
– Computer Based Testing (CBT)– Examples
• GRE and GMAT
• Remote– Internet based testing– Examples
• www.eexam.com• www.netexam.com
• Any Time exams
Computer Based Testing (CBT)Computer Based Testing (CBT)
• Different Question-Paper for each examinee– Generated dynamically
• Adaptive– Different weights given to different questions– Next question decided on the basis of
• difficulty level and • correctness of answer to previous question
Question Bank
Generator
Question Paper
Feedback
Existing Internet Based Testing SchemesExisting Internet Based Testing Schemes
• Front End– Mostly “HTML - form based”– answers sent using ‘GET’ and ‘POST’ methods– Java applets, flash
• Back End– CGI scripts– Java servlets
• Security– Authentication done using ‘login - password’– May use “https” for secure exchange
• Some issues – Web Servers are basically stateless
Important PointsImportant Points
• Existing models are basically– Pull based – Client-Server
• Extending Internet based evaluation techniques– Push model– Different kinds of content– Dynamic organization of content– Off-line examination V/S on-line examination– Subjective answers (not just objective)
• Key technical issues– How to deliver the exam content?– How to evaluate the answers?
• Our solution– Use Mobile Agents
Call to server procedure
DataClient Serverresults
Procedure
DataClient ServerProcedure
Client Server
Code on Demand
DataClient Serverresults
Procedure
Remote Evaluation
Distributed System Structuring MechanismsDistributed System Structuring Mechanisms
DataClient Server
DataServer
DataServer
Procedure+
State
DataServer
Procedure+
State
Procedure+
State
Procedure+
State
Mobile Agents
Procedure+
State
How Mobile Agents Help?How Mobile Agents Help?
• Map directly to real life situations• Need a generic execution environment• Can work in both modes
– push– pull
• Can work off-line• Provide local interactions • Provide multi-hop solutions
DataBase
Desktop
Server
SystemResources
Laptop
User Application Legacy Software
Execution EnvironmentMobile Agent
Service AgentApplication
Agent MigrationLocal Communication
Global Communication
Typical Mobile Agent FrameworkTypical Mobile Agent Framework
MAFsMAFs
• Components– Life Cycle– Navigation – Communication– Security
• Classification basis– Type of migration and code shipping mechanism– Agent tracking and directory service– Resource access control mechanism– Communication
• Local, global, communicating partners
• Systems Surveyed– 50+ frameworks – Notable : Aglets, Concordia, Voyager, Grasshopper, D’Agents, Mole
Voyager - Our ChoiceVoyager - Our Choice
• Better remote messaging• Generalized distributed object computing platform• Compatibility with latest java version• Easy creation of remote objects• Moving objects
– relative and absolute
• Other– Federated directory service– Different kinds of messaging (sync, one-way, future)– Object and agent persistence support– Distributed event handling– Security manager– Compatible with CORBA and DCOM
Examination Process (Three Stages)Examination Process (Three Stages)
• Exam setting– examiners set the question papers
• Distribution and testing– question papers are presented to the students
• Evaluation and result compilation– answers are collected and results compiled
• Design guidelines– Automate as much as possible– Simplify requirements of infrastructure at different ends– Reliability
PS-2
PS = Paper Setter
PS-3
PS-4PS-4
PS-1
Paper Assembler
Comprehensive Paper
= Mobile Agents
To Distribution Server
Examination Setting: OverviewExamination Setting: Overview
NS
N-1
N-2
NS
NS
Cloning
Install Agent
GUI
Fetch Agent
Launcher
Controller GUINS = Name ServerN = Paper Setter Node
Examination Setting: DetailsExamination Setting: Details
Dynamic Upgrade
RemoteSetterGUIFetchAgentInstallAgent
new RemoteSetterGUI()
NamingService
register( )
getGUIName()
addEnhancePanel()
removeEnhancePanel()
new EnhancePanel()
getGUIReference()
Dynamic UpgradationDynamic Upgradation
DistributionServer
Exam Center Distribution
Server
Single copy of paper
c9611060
Separate Copy per user
List of Students enrolled…
…
Each Candidate get a Copy
1
4
3
2
Answered and Returned
5
Each copy returned
Distribution and TestingDistribution and Testing
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Examiner B
Examiner A
Examiner D
Examiner C
Distributor
Results
……
Agents collaborate to produce the final result
Objective Questions Evaluator
Distribution Server
Evaluation and Result CompilationEvaluation and Result Compilation
Evaluation Center
Examiner –1
Objective Question Evaluator
Distribution Server –1
Paper Coordinator
Question Paper Courier Agent
Student- 1a Student- 1b Student- 2a Student- 2b
Distribution Server –2
Result PublishingServer
Answer Paper Agent
Examiner –2
Stage 2 and 3 : DetailsStage 2 and 3 : Details
Salient Features of the DesignSalient Features of the Design
• Generic execution environments on each machine– Remote code installation
• After distribution and before collection– The students work off-line
• Agent creation by distribution servers– Not student machines
• Workflow between examiners• Automated compilation of results
Measuring Response TimesMeasuring Response Times
050
100150
200250
300350
400450
500
1 2 3 4 5 6 7 8 9 10 11
Request Number
Res
po
se i
n m
illi
seco
nd
Mobile Agent
Client-Server
Student Paper Interface Client
MA Interactions
Client –Server Interactions
Incorporating Dynamic ContentsIncorporating Dynamic Contents
New Level
Old Level
• MQPs can be organized into various skill levels• Once a person has finished one level, a new level
2 can be sent
ConclusionsConclusions
• Mobile Agents provide effective and flexible mechanisms for structuring distributed systems like distance evaluation
• Advantages– Student response times– Handling objective and subjective contents– Application level multicasting– Dynamic upgradation of applications– Support for heterogeneous execution environments– Centralized control and management of logistics and security of
examination process
• Some Issues– Reliability– Persistence– Security– Infrastructures
Questions ?
Thank You