MADE Mobile Agents based system for Distance Evaluation Vikram Jamwal KReSIT, IIT Bombay Guide : Prof. Sridhar Iyer

Contents The application –Motivation –Domain –Existing Schemes Distributed system structuring –Prevailing paradigms –Mobile agent approach Mobile agent frameworks Our model Experimentation Conclusions

Distance 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 mechanisms Where does the database reside? Locally –Computer Based Testing (CBT) –Examples GRE and GMAT Remote –Internet based testing –Examples Any Time exams

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 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 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 Data Client Server results Procedure Data Client Server Procedure Client Server Code on Demand Data Client Server results Procedure Remote Evaluation Distributed System Structuring Mechanisms

Data Client Server Data Server Data Server Procedure + State Data Server Procedure + State Procedure + State Procedure + State Mobile Agents Procedure + State

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

Data Base Desktop Server System Resources Laptop User Application Legacy Software Execution Environment Mobile Agent Service Agent Application Agent Migration Local Communication Global Communication Typical Mobile Agent Framework

MAFs 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 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) 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-4 PS-1 Paper Assembler Comprehensive Paper = Mobile Agents To Distribution Server Examination Setting: Overview

NS N- 1 N- 2 NS Cloning Install Agent GUI Fetch Agent Launcher Controller GUI NS = Name Server N = Paper Setter Node Examination Setting: Details

Dynamic Upgrade

RemoteSetterGUIFetchAgentInstallAgent new RemoteSetterGUI() NamingService register( ) getGUIName() addEnhancePanel() removeEnhancePanel() new EnhancePanel() getGUIReference() Dynamic Upgradation

Distribution Server Exam Center Distribution Server Single copy of paper c Separate Copy per user List of Students enrolled … Each Candidate get a Copy Answered and Returned 5 Each copy returned Distribution and Testing

c 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 Compilation

Evaluation Center Examiner –1 Objective Question Evaluator Distribution Server –1 Paper Coordinator Question Paper Courier Agent Student- 1aStudent- 1bStudent- 2aStudent- 2b Distribution Server –2 Result Publishing Server Answer Paper Agent Examiner –2 Stage 2 and 3 : Details

Salient 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 Times

Student Paper Interface Client MA Interactions Client –Server Interactions

Incorporating 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

Conclusions 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