UNIVERSITI PUTRA MALAYSIA

A PROTOTYPE OF WEB-BASED SIMULATION ENVIRONMENT (WEBSIM)

TAN KEE LEONG

FK 2000 4

A PROTOTYPE OF \VEB-BASED SnlULATION ENVIRONMENT

(WEBSnl)

By

TAN KEE LEONG

Thesis Submitted in Fulfilment of the Requirements for the Degree of Master of Science in Faculty of Engineering

Universiti Putra Malaysia

November 2000

DEDICATION

Thi.\ hook is dedicated to Illy parents:

Mdm. Koo Kim Lai and my late./ctther Mr. Tan (JlIat Cry Tan Ban Po (1945 -1998) -from whom 1 learned the vallie (d'hard work and perseverance.

n

Abstract of the thesis submitted to the Senate of Universiti Putra Malaysia in fulfilment of the requirements for the degree of Master of Science.

A PROTOTYPE OF WEB-BASED SIMULATION ENVIRONMENT

(WEBSIM)

By

TAN KEE LEONG

November 2000

Chair man : Associate Professor BOI'hanuddin Mohd. Ali, Ph.D.

Faculty : Engineering

Computer simulation is the discipline of designing a model of an actual or

theoretical physical system, executing the model on a computer, and analysing the

execution output. Among the popular simulation tools are Mil3 Opnet, Mathworks

MATLAB and even self-developed simulation program (using language such as

Pascal, Fortran and C/C++) . However, these simulation tools have limitations such

as platform dependent, expensive cost, maintenance difficulties and limited in

reusability.

One of the methods to overcome this limitation is by implementing web-

based simulation. Web-based simulation allows simulation to be carried out over the

Internet using a standard web browser. The usage of web browsers make the Internet

a very user-friendly environment by integrating all related resources into a single

tool that eliminates the steep learning curve for novice simulation users.

In this thesis, we present the web-based simulation environment project

(Websim) . Websim uploads a simulation program (developed using C/C++) in

111

billary format, generates cl web-Interface for the program and allows users to access

the slmulatlOn program y 1<1 the Internet The results generated from the slmulatlOn

program would be translated Into cln tmage file Fmally, the Image file IS embedded

mto an HTML fIle, and returned to Webslm users Webs 1m IS mamly developed

usmg the combmatlOn of CGI and Javascnpt technologIes The server-slde CGI

scnpts, wntten III Perl process the vaflous requests from users, whIle the chent-slde

Javascnpt IS used to perform user Inputs valIdatlOns Thus, lessen the workload of

the server and tIghten� {he secuflty

Webslm IS able to receIve the slmulatlOn program m executable format and

prOVIde a web mterface for It ThIS gIves the flexIbIhty and convenIence of usmg the

programmmg language of chOIce for the slmulatlOn modeller, and to mtegrate It WIth

the web BeSIdes that, Webs 1m also allows the storage of SImulatIOn program on a

web server, thus could act as an onlme store for sImulatIOn programs ThIS permIts

the sharmg of SImulatIOn program over the Internet, to an exclUSIve user groups or to

the general publIc FInally, Webslm could act as a teachmg tool m school and

UnIVerSItIes, espeCIally for courses mvolvIng modellIng and simulatlOn It allows

teachmg and learnIng to be done through the Internet, hence could asSISt students m

havmg a better understandmg on certam tOpICS or concepts

IV

Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia untuk memenuhi keperluan ijazah Master Sains.

Pengerusi

Faklliti

SATU CONTOH PERSEKITARAN SIMULASI WEB (WEBSIM)

Oleh

TAN KEE LEONG

November 2000

: Profesor Madya Bor hanllddin Mohd. Ali, Ph.D.

: Kejllruteraan

Simulasi komputer merupakan satu disiplin yang melibatkan proses

merekabentuk model sebenar atau model sistem fizikal teori, melaksanakan model

tersebut pada komputer, dan menganalisis hasil perlaksanaan model tersebut. Antara

perisian simulasi yang popular ialah Mi13 Opnet, Mathworks MA TLAB, dan

perisian yang ditulis sendiri menggunakan bahasa paras tinggi seperti Pascal, Fortran

dan CIC++. Namun, perisian-perisian simulasi seumpama ini mempunyai kelemahan

seperti tertakluk kepada pelantaran, kos yang tinggi, kesukaran dalam memelihara

serta menyokong perisian, dan penggunaan-semula yang terhad.

Salah satu cara untuk mengatasi kelemahan tersebut ialah dengan

melaksanakan simulasi web. Dengan simulasi web, proses simulasi boleh

dilaksanakan pada Internet dengan menggunakan sebarang pelayan laman biasa.

Penggunaan pelayan laman juga menjadikan Internet satu persekitaran yang mudah,

iaitu dengan menggabungkan sumber-sumber yang berkaitan untuk menjadi satu

perisian yang senang dipelajari.

v

Dalam tests ml, kaml melaporkan satu prolek persekttaran slmulasl web,

kaml kenah sebagm 'Websnn" Webslm menenma satu aturcara slmu)asl (ditulls

menggunakan bahasa CIC++) da)am format bman, menyedIakan satu perantaraan

web (dalam bentuk fall HTML) kepada aturcara tersebut, dan seterusnya

membenarkan la dlcapal meJalUl Internet Hast! danpada aturcara slmulasl tersebut

akan dlterJemah menladl satu faIl graflk Akhlf sekah, faIl graflk tersebut

dlmasukkan ke dalam fall HTML tadl dan dlhantar kembah kepada pengguna

Webslm WebSlm dlbma menggunakan gabungan teknologl CGI dan Javascnpt

Aturcara CGI yang dltulIs dalam bahasa Perl melaksanakan pelbagm proses dl

penngkat pelayan Sementara ItU, Javascnpt dlgunakan untuk memenksa mput

pengguna sebelum dlhantar kepada pelayan, dengan ltu mengurangkm beban

pelayan dan menmgkatkan tahap keselamatan slstem pada keseluruhannya

Webslm memben kemudahan flekslbel kepada pengguna untuk

menggunakan bahasa pengaturcaraan pllIhan sendm Selam ItU, Webslm Juga

membenarkan aturcara slmulasl dlSlmpan dl dalam pelayan web, lantas boleh

dlJadlkan tempat Slmpanan aturcara slmulasl yang boleh dlcapal secara lang sung 1m

menglzmkan aturcara slmulasl tersebut dlcapm pada Internet, sarna ada kepada

kumpulan tertentu yang terhad ataupun kepada semua pengguna am Akhlr kata,

Webslm Juga boleh dlJadlkan satu alat bantuan mengaJar dl sekolah dan ulllversltt,

khasnya kepada kursus-kursus yang mehbatkan pemodelan dan slrnulasl Webslrn

membenarkan pengaJaran dan pembelaJaran dlbuat melalUl Internet, dan ml akan

dapat rnernbantu menmgglkan pemahaman para pelaJar bagl sesuatu toplk

\ 1

ACKNOWLEDGEMENTS

I am indebted to several people who have directly or indirectly contributed to this dissertation work. The knowledge and experiences I have gained with them cannot be measured in words. Neither can the appreciation I have for them. The following list, by no means exhaustive, is an attempt to acknowledge at least a few of these

people.

To all lecturers, staffs and friends in the Department

Dr. Borhan Dr. V Prakash

Puan Nor Kamariah Dr. Abdul Rahman Ramli

Puan Roslizah

Chee Boon Kok Low Wai Yan

Fawwaz Hadi

Ali Prihandoko

Choong Khong Neng Yem Poh Cheang

Fei Wang Li Ku DayChyi

Angeline Michael Zubeir Khalid

Mabntk Abdul Lariff

HanifJ Fizan

Puan Aishah Puan Salbiah Puan Rufina

Puan Noorlida Abang Nor

Uncle Sa vier

My beloved family members and relatives:

My mother LayKi

Kee Swee Poay Lin

Poay Phing

Kor Lian Kor .fin

Kor Peng Loo Ching

Sze Fei

Ching .fi Uncle Kee Peng

Auntie Ong Lin a Lilia

A E Tendong Siew Kheng Siew Chin

Uncle Gan Uncle Wee

Auntie Bee Liang Uncle Guan Chit

Susi

My housemates and friends in the campus

Bro. Tan Ho Soon Sek Thai Sai Tin

Boo Ping Kah Wah

Cheng Tong Tien Siong

Shau Meng

Mr.Ong Wein Leong Peng Siong

Chong Yong Babbu

My respectfitl residents of Kalyana, Mudita, Bodhi,

Ananda and Dhammarakha Lodge.

Lai Hsiang Lewis

Teng Yong SheowFoong Choon Yan

Sau Ping

I share the happiness and joy with all of you!

VII

1 certify that an Exanllnation Committee met on 6\h November 2000, to conduct the final examination of Tan Kee Leong , on h is l'vlaster of Science thesis entitled "A Pro t otype of 'Neb-based SImulation f::< nyironment (\Vebsim)" in accordance with Lni\crsiti Pertanian vlalaysia (Higher Degree) Act 1980 and Universiti Pertanian \lalaysia (Highel Deg ree) Regulations jl)S 1 The Committee recommends that the can didate be awarded the lcle\ant de�lee l\lembers of the Examination Co mmittee are :\') follows

ABDUL RAHrrL\N RA\lLL Ph.D. Lecturer Faculty of Engineering Lni\ ersiti Putra ;\'falay�ia (Chairman)

BORHANUDDIN MOHO. ALI, Ph.D. Associate Professor Faculty of Engineering Universiti Putra Malaysia (Member)

VEERARAGHA VAN PRAKASH, Ph.D.

Lecturer Faculty of E ngineering Universiti Putra Malaysia (�[ember)

�OR KA1\lARIAH NOORDrN. Lecturer Faculty of Engineering Universiti Putra Malaysia (;\;Iember)

Q -------- - -------�----------------------------------

HAZALI MOHAYIDIN, Ph.D. Professor I Deputy Dean of Graduate School Universiti Putra Malaysia

Date: 1;) NOV 2000

VlIl

This thesis was submItted to the Senate of Universiti Putra Malaysia and was accepted as fulfilment of the requirements for the degree of Master of Science

-----��----------------------------

KAMIS AW ANG, Ph.D. Associate Professor, Dean of Graduate School Universiti Putra Malaysia

Date 14 DEC 2000

1:-'

DECLARATION

I hereby declare that the thesIs IS based on my original work except for quotations and citations which ha\ e been duly acknowledged I also declare that it has not been previously or concurrently submItted for my other degree at UPM or other institutions

--------�-�-------------------------------

Candidate Name TAN KEE LEONG

Date 7 November 2000

T <\BLE OF CONTENTS

DEDICATION ABSTRACT ABSTRAK ACKNOWLEDGEMENTS APPROV AL SHEETS D EC LARA TION FORM LIST OF TABLES LIST OF FIGURES LIST OF ABBREVIATIONS

CHAPTER

I INTRODUCTION Computer SImulatIOn Web-based SimulatIOn Charactenstlcs of Web-Based SimulatIOn SIgmficance of \Vebslm ObjectIves OrgamsatIOn of TheSIS

n LITERA TURE REVIEW PotentIal of WWW to Support SImulatIon

Education and Trammg SImulatIOn Programs

Web-based SImulatIOn EnvIronment SerVIce ArchItecture of Web-based SImulatIOn System

Remote SImulatIOn usmg CGI Remote SimulatIOn usmg Java Data Server Local SllTIulatlOn based on Java Applets ConclusIOn

SImulatIOn Languages C C++

Java ConclusIOn

Web-based SimulatIOn TechnologIes Common Gateway Interface PractIcal ExtractIOn and Report Language (PERL) Javascnpt Java RMI

Plottmg Tools ConclUSion

\.\

Page 11 III

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In WEBSIM SYSTEM DESIGN AND ARCHITECTURE

IntroductIOn 28 Client Server ArchItecture 29

Web Browser 30 HTTP Web Server 31

ControllIng CGI Scnpt 32

S ImulatlOn Program 32

Gnuplot 34

System ServIces 34

User AuthorizatIon ServIce 35 Sm1UlatlOn Program Upload ServIce 35

Web Interface Generation Service 35

Program ExecutIOn ServIce 36

Graph Plotting ServIce 36

Image VIewer ServIce 36

Site Management ServIce 37

WebsIm Actors 37

Websim LogIcal DesIgn 38

L ogIn Module 41

Upload WIzard Module 42

Site Manager Module 43

Image VIewer Module 45

P lotting Module 46 SImulation Run Module 47

Files Used in Websim 48

IV SYSTEM IMPLEMENTATION

IntroductIOn 50

Implementation Tools 51

Generating Simulation Program Web-Interface 53

Step 1 Upload sImulation program 53

Step 2 Upload status notIfication 54

Step 3 Enter web-interface settmgs 55

Step 4 Preview and fmalise settings 56

Performing Simulation over the Web 58

Step 1 Enter simulation parameters 60

Step 2 Invokmg simulation program 61

Step 3 Generating simulation results and graph settings flIes 62

Presentation of Simulation Results 63

Security Issues 65

Web Server Security 68

CGI Scnpt Security 68

,\11

V RESULTS AND DISCUSSION

Introduction 7 1 72 73 74 77 79 80 8 1 82 83

Experimental Setup Machme ConfIguratIOn

Functional Testmg Performance EvaluatIon LImItations and Proposed SolutIons

Webslm securIty MultI-users supports SimulatIOn Program

ConclusIOn

VI CONCLUSIONS AND FUTURE WORK

Future Works 84 AddItIonal Servlce� 84 Database 85 Graphical User Interface 86 AnImatIOn and VIsualizatIOn 87 Websim Documentation and User GUIde 8 8

Websim ContnbutlOns 89 Conclusion 90

REFERENCES 92

APPENDICES 96 A-I Source codes for a sample of simulation program to generate and

show the characteristIC of a semiconductor diode 97 A-2

A-3

Source codes for a sample of SImulation program to generate a truncated Fourier senes Source codes for a sample of simulation program to find the effect of tImeout on GBN throughput

BIODATA OF AUTHOR

\,111

98

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1 04

LIST OF TABLES

Table Page

Companson between the performance of C++ and Java 18

2 FIles used and theIr descflptlons In Webslm 48

3 ConfIguratIons for Webslm Server 73

4 ConfIguratIons for Chent A 73

5 ConfIguratIons for Chent B 74

6 Webslm performance when accessed from local machIne 78

7 Websim performance when accessed from a machIne wIthIn the same LAN 78

8 Webslm performance when accessed from another machIne outsIde campus network, VIa Internet 79

\1\

LIST OF FIGURES

Figure Page

Remote SIn1Ulation & AmmatIOn and data transfer II

2 Remote SImulatIOn and Local VIsualIzatIOn 12

3 ClIent-Site sImulatIon WIth loaded applets 1 3

4 Remote Method� InvocatIOn 24

5 ClIent-server interactIOn In Webslm 29

6 Screen shot from the Input form 3 1

7 C/C++ SimulatIOn Program Template 3 3

8 Input and Output Parameter of Simulatton System 34

9 RelatIOnship between Webslm users and their services 3 8

1 0 Webslm Modules 3 9

1 1 Dialogue Diagram showmg sequence of mteractIOn between Webslm users and the system 40

1 2 DFD of Login Module 4 1

1 3 DFD of Upload Wizard Module 42

1 4 DFD of Site Manager Module - Delete Option 43

1 5 DFD of Site Manager Module - Edit OptIOn 44

1 6 DFD of Site Manager Module - Upload OptIOn 45

1 7 D FD of Image VIewer 46

1 8 DFD of Plottmg Modul� 46

1 9 DFD of SimulatIOn Run Module 47

20 The layout o f the duectones and ftIes for Webslm 49

21 Block DIagram Of Webslm System ImplementatIOn 51

22 UploadIng SImulatIOn Program 54

23 ConfirmatIOn on Successful SImulatIOn Program Upload 55

24 Form CollectIng InformatIOn for Web-Interface FIle 56

25 PrevIew of HTML Interface FIle 57

26 DIsplay URL of SImulatlOn Prolect Folder to User 58

27 CGI-based Web ConnectIOn for a SImulator 59

28 Input sImulatlOn parameters VIa web-Interface page 60

29 Final HTML page contaInIng the output graph 65

30 Webslm Experimental Setup EnvIronment 72

31 Charactenstlc of semIconductor dIOde 75

32 A truncated Founer senes 76

33 Simulation output shOWIng the GBN throughput for 54 bytes packet 77

34 Example of components created USIng Java A WT class 86

35 Example of several Java Swing Components 87

36 A 3-D Image created In VRML 88

\.VI

API

AWT

CGI

CORBA

GBN

HTML

HTTP

IP

JVM

LAN

ODBC

ORB

PERL

RMl

S&A

SMTP

TCP

GUI

UML

VRML

WAN

WWW

LIST OF ABBREVlA TIONS

Application Programmer Interface

Abstract Window Toolkit

Common Gateway Interface

Common Object Request Broker Architecture

Go Back N.

Hyper Text Markup Language

Hyper Text Transfer Protocol

Internet Protocol

J(lva Virtual Machine

Local Area Network

Open Database Connectivity

Object Request Broker

Practical Extract Report Language

Remote Method Invocation

Simulation and Animation

Simple Mail Transfer Protocol

Transport Control Protocol

Graphical User Interface

Unified Modelling Language

Virtual Reality Markup Language

Wide Area Network

World Wide Web

xvii

CHAPTER I

INTRODUCTION

Computer Simulation

Computer simulation is the discipline of designing a model of an actual or

theoretical physical system, executing the model on a computer, and analysing the

execution output [Fishwick, 1 995] . In general, s imulation is to pretend that one deals

with a real thing while really working with an imitation. In operational research the

i mitation is a computer model of the s imulated reality. Models are used in industry

and commerce and military because to make experiment with real systems is very

costly, dangerous and sometimes impossible. Provided that models are adequate

descriptions of reality, experimenting with them can save money, suffering and time

[Pollatschek, 1 999] .

There are generally two types of simulation :

• Discrete Event Simulation. When the numbers of events are finite and between

two consecutive items nothing happens, we call this kind of s imulation a discrete

event. Car arrivals and departures occurred at distinct points of time are example

of discrete event s imulation.

2

• Continuous Simulation In some systems the state changes a l l the time, not just

at time of some discrete events For example water l evel in a reservoir with given

in and outflow m ay change al l the t ime

Simulation i s often performed by writing a computer code to represent a

system model , or as some kind of input into a simulator software. S imulation may be

carried out:

• On a spreadsheet

• By running a computer program written in some general l anguage (such

as Fortran, C/C++ or Pascal )

• By running a computer program written m some special l anguage for

simulations

• By running specially built simulator with appropriate input.

These four methods are the most popular methods of perfonning simulations .

But due to the dependency on the local standalone system they are running on, these

s imulation methods suffers several disadvantages such as p latfonn-dependent,

machine-dependent, and requi re longer learning curve With the current advancement

in Internet and web technology, we propose a partial solution to the above problems

with a Web-based Simulation Environment (Websim) project. Websim provides a

dynamic web interface for a standalone simulation engine and allow the performi!lg

of simulation works over the World Wide Web (WWW). Websim also provides a

s imulation environment where users can examine the simulation outputs to verify

and validate their system model . The outputs can either be in text or graphical

representation.

3

Web-based Simulation

The Internet IS a loo<;ely connected world-wide network of heterogeneous

computers and the WWW 1<; a set of on-l me hypermedia documents that resides on

the Internet The WWW was conceived as a set of simple Internet-based chent/server

protocols for transfernng and rendenng documents of a pnman ly textual nature

What dlstIngmshed the web 's mode of communIcatIng mformatlOn from other

Internet-based tools that preceded It (e-maIl and FTP) was the provISIon for

embeddIng hyperlInks that al lows users to eas Ily navIgate between related

documents HypermedIa documents are buIlt USIng a language called Hypertext

Markup Language (HTML) Access to the web IS afforded USIng the web browser

such as Netscape NaVigator or Internet Explorer

Web-based sImulatIOn was Introduced to perform all steps needed for

sImulatIOn over the Internet and the web In other words, It uses the web as a means

of access to sImulatIOn models as well as ItS use as a p latform for the creatIon,

executIon and dIstnbutlOn of sImulatIOn models [Nam and KIm, 1 999]

Most of the eXIstIng Web-based simulatIOn tools focused maInly on the

development of the runtIme sIP"ulatlOn hbranes and mechanIsms on the Web , such as

SImJava [Howell, 1 999], Javaslm [Javaslm, 1 999], S I lk [Healy and Kllgore, 1 998]

and the development of the dlstnbuted sImulatIOn enVIronments USIng ORB

technology such as JavaRMI and CORBA [Orfah and Harkey, 1 997] Some of these

tools reqmre sImulatIOn model developers to be good at C/C++, Java and sImulatIOn

languages rbwever, performance of web applIcatIOns developed In Java are

relatively slow In speed To ease the burden of modellers, GUI based modellIng

4

envIronments are essentldl �mlUlatlon tools lIke OPNET [MIL3 , 1 997] and DIgItal

Workshop [FIShwlck 1998] support the vIsual development envIronments, but

OPNET could not support Web-based SimulatIon capabI l Ity, and DIgItal Workshop

could be used only for digItal CirCUIt design

Most of the eXlstmg commercIal and non-commercIal SImulatIOn tools are

tYPIcally platform-dependent and are not desIgned to work In the Internet or the

Intranet We acknowledge that It IS eaSIer to wnte a SImulatIOn model USIng a

general-purpose language such as C/C-I-+ because the CIC++ IS very popular and

easy to learn The only problem With programs wntten In C/C++ IS that they are

typIcally machIne dependent and standalone In thIS theSIS, Webslm project acts as

the m ISSIng JIgsaw whIch encapsulates the standalone programs In CIC++ WIth a web

Interface, and allows It to be accessIble through the web

Characteristics of Web-based Simulation

A web-based SImulatIOn environment refers to a web applIcatIOn system, whIch

proVIdes a dynamIc web Interface for a SImulatIOn tool , and allows the performIng of

S ImulatIOn works over the WWW ThIS enVIronment IS accessIble WIth a web

browser and has the fol lOWIng charactenstIcs

• Supports a model lIng tool whIch IS Independent of hardware and software

platforms

• Supports a graphIcal user Interface for easy modellIng

• Supports executIOn over the web

• Able to store and dIsplay the SImulatIOn results over the web

In this thesis we develop the Websim, a simulation environment for self­

developed simulation tool Websim shows how one could extend the capabi l ity of

s imulation tools into the web Websim allows a simulation model to be uploaded to a

web server, and automatically generate a web interface for the simulation model

Websim can be accessed on any platform (Unix, PC or Mac) using a standard web

browser. With this simulation envi ronment, an easier and faster integration of

simulation and visualization techniques and tools into the Internet can be real ized.

Significance of \"ebsi m

There are three significant aspects o f this thesis . First, it i s the abil ity of

Webs im to produce a web-based simulator on a standalone s imulation engine.

Webs im simply receive the simulation engine in executable formats and provide a

web interface to it. Secondly, Websim act as the online store for a col lection of

simulation models . For example, researchers from the same group could upload their

simulation models to Websim, so that their simulation works could be easily referred

and executed by other researchers from other parts of the world . Finally Websim

could act as a teaching aid / tools in schools and universities . This would be very

helpful especially for courses involving modeling and simulation, where lecturers

could ask several students who are good in C/C++ programming to develop

simulation engines, and upload them to Websim. These web-based simulation

engines could assist other peers in having a better understanding of certain topics or

concepts .

6

Objective�

One Important property of WebSlm IS that the executIOn of simulatIOn runs on

a remote server It IS designed to provide dlstnbuted and platform mdependent

features to multiple concurrent users For mstance, a user could perform the

sImulatIOn works at home U<;Ing the sImulator located at his office, whI le another

col league at the office watches the results shown on the computer screen vIa a web

browser The aIm of the theSIS IS to develop a server-side web applIcatIOn of a web­

based sImulatIOn environment for self-developed sImulatIOn program by utdlzmg

Common Gateway Interface (CGI) and Javascnpt technologies

The ObjectIves of thiS theSIS are as fol lows

• To enable a standalone sImulatIOn program to be executed by multiple concurrent

chents over the web

• To produce web mterface for the SImulatIOn program based on ItS mput and

output data

• To develop a server side appl IcatIOn WhICh could receIve the self-developed

simulatIOn program (executables CIC++ program fi le)

• To proVIde an mterface to support executIOn of the sImulatIOn program over the

web

• To develop some useful server-SIde admmlstrator modules to manage Webslm

ThiS mclude features such as uploadmg, edltmg, mamtammg, and the l Ike

• To develop several simulatIOn program as samples to test and evaluate the

performance of Webslm

7

Organisation of Thesis

ThIS thesl<; 1<; organIsed mto SIX chapters Chapter 1 provIde" a bnef

IntroductIOn to web-based <;lmulatlOn �ystems and the s IgnIficance of Webslm

Chapter 2 presents the IIterdture reVIew on varIOUS web-based sImulatIOn tOpIC� The

hIstory and the development of web-based sImulatIOn are also mcluded Chapter 3

descrIbes the desIgn methodology employed and the system archItecture defined for

Websim As CGI plays an Important role m thIS Pro1ect, varIOUS Issues pertammg to

thIS area are hIghlIghted The system ImplementatIOn IS descrIbed m Chapter 4 The

performance testmg, evaluatIon of result<; and general lImItatIOns of Webslm are

presented m Chapter 'i The final chapter dIscusses the sIgnIficance and contnbutlOn

of Webslm, Its future works and conclUSIOn of this project