Client, server based statistical computing [Elektronische Ressource] / von Heiko Lehmann

Heiko Lehmann

Sujets

• Informatik
• Mathematics

Informations

• Publié par: humboldt-universitat_zu_berlin
• Publié le: 01 janvier 2004
• Nombre de lectures: 16
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Client/Server Based Statistical Computing
D I S S E R T A T I O N
zur Erlangung des akademischen Grades
doctor rerum politicarum
(dr. rer. pol.)
¨im Fach Statistik und Okonometrie
eingereicht an der
Wirtschaftswissenschaftliche Fakult¨at
Humboldt-Universit¨at zu Berlin
von
Herr Dipl.-Kfm. Heiko Lehmann
geboren am 26.06.1970 in Berlin
Pr¨asident der Humboldt-Universit¨at zu Berlin:
Prof. Dr. Jur¨ gen Mlynek
Dekan der Wirtschaftswissenschaftliche Fakult¨at:
Prof. Michael C. Burda, Ph.D.
Gutachter:
1. Prof. Dr. Wolfgang H¨ardle
2. Prof. Oliver Gun¨ ther, Ph.D.
eingereicht am: 02. April 2004
Tag der mundlic¨ hen Prufung:¨ 12. Mai 2004iiAbstract
In today’s world, many statistical questions require the use of computational
assistance. Our approach, presented in this thesis, combines the possibilities
ofthepowerfulstatisticalsoftwareenvironmentXploRe, withtheadvantages
of distributed client/server applications, and the opportunities offered by the
Internet. In order to offer the client access to a large community, the Java
language is used to implement the client’s functionalities. The result is a
statistical package - usable via the World Wide Web - that can be used like
a traditional statistical software package, but without the need for installing
the entire software package on the user’s computer.
This thesis provides an overview of the desired software environment, and
illustrates the general structure with the implementation of the XploRe
Quantlet Client/Server architecture. It also shows applications, in which
this architecture has already been integrated.
Keywords:
Client/Server Architecture, XploRe, Java, Statistical Computing, Electronic
Books, Interactive Teaching
iiiivZusammenfassung
Viele statistische Problemstellungen erfordern in der heutigen Zeit den
Einsatz von Computern. Der von uns in dieser Dissertation vorgestell-
te Ansatz kombiniert die F¨ahigkeiten der statistischen Softwareumgebung
XploRe, mit den Vorteilen einer verteilten Client/Server Anwendung und
den Moglichkeiten, die sich durch das Internet eroffnen. Um den Client ei-¨ ¨
ner großen Gruppe von Anwendern zuganglich zu machen, wurde Java zu¨
seiner Realisierung verwendet. Das Ergebnis ist ein Statistikpaket, nutzbar
via World Wide Web, das wie ein herkommli¨ ches statistisches Softwarepaket
verwendet werden kann, ohne die Notwendigkeit, das gesamte Softwarepaket
zu installieren.
¨Die vorliegende Arbeit gibt einen Uberblick ub¨ er die notwendige Softwa-
reumgebung und erlaut¨ ert die generelle Struktur der XploRe Quantlet
Client/Server Architektur. Die Arbeit zeigt außerdem Anwendungen, in die
diese Architektur bereits integriert wurde.
Schlagworter:¨
Client/Server Architektur, XploRe, Java, Statistisches Rechnen, Elektroni-
sche Buc¨ her, Interaktives Lehren
vviAcknowledgments
Before actually starting to work on the XploRe Quantlet Client/Server
project, andthisthesisitself, acknowledgmentsinpapersoftenseemedsome-
howstrangetome. NowthatIwentthroughtheentireprocessmyself,Ihave
revised my attitude. It takes much more than just a couple of well-known
colleagues to achieve one goal.
First of all I would like to thank my family - my wife Manja and my son
Timo - for their patience with me and for supporting this project over the
last years.
I would also like to express my gratitude to my adviser Prof. Dr. Wolf-
gang H¨ardle, who always supported the development of this project with his
thoughtful advise and fruitful discussions.
In the same respect, I would like to extend my appreciation to Prof. Oliver
Gun¨ ther, Ph.D., for his review and comments during the development of this
thesis.
For technical support, I would like to thank the members of the XploRe
team - Dr. Sigbert Klinke for his continuous help and development of the
XploRe Quantlet Server, Dr. Torsten Kleinow and J¨org Feuerhake for the
immense effort they put into the client/server project, and last but not least
Dr. Zdenek Hlavka, for his extensive testing and evaluation of the XploRe
Quantlet Client.
I would likewise reserve my gratitude to Jennifer A. Trimble, Paul T. Harvey
andDavidC.Trimble,Ph.D.fortheirvaluablehelpincompletingthisthesis.
Berlin, April 2004
Heiko Lehmann
viiviiiContents
1 Introduction 1
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Structure of this Thesis . . . . . . . . . . . . . . . . . . . . . . 4
2 Client/Server Computing 7
2.1 Client/Server Computing - A Closer Look . . . . . . . . . . . 8
2.1.1 Client . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1.2 Server . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1.3 Middleware . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1.4 N-Tiered Models . . . . . . . . . . . . . . . . . . . . . 10
2.1.5 Fat Clients versus Thin Clients . . . . . . . . . . . . . 11
2.2 From Client/Server to Distributed Computing . . . . . . . . . 13
2.3 Web Services . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.4 Statistical Computing vs. Web Services . . . . . . . . . . . . . 18
3 XploRe Quantlet Client/Server Model 21
3.1 XploRe Quantlet Server . . . . . . . . . . . . . . . . . . . . . 23
3.2 Middleware MD*Serv . . . . . . . . . . . . . . . . . . . . . . . 24
3.3 MD*Crypt Package . . . . . . . . . . . . . . . . . . . . . . . . 26
3.3.1 Structure . . . . . . . . . . . . . . . . . . . . . . . . . 27
ixCONTENTS
3.3.2 Client Communication Process. . . . . . . . . . . . . . 28
3.3.3 Programming a Simple Client . . . . . . . . . . . . . . 38
3.4 XploRe Quantlet Client . . . . . . . . . . . . . . . . . . . . . 40
4 XQC in Detail 43
4.1 XQC in Action . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4.1.1 Application versus Applet . . . . . . . . . . . . . . . . 43
4.1.2 Configuration . . . . . . . . . . . . . . . . . . . . . . . 45
4.1.3 Getting Connected . . . . . . . . . . . . . . . . . . . . 46
4.1.4 Desktop . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.1.5 XploRe Quantlet Editor . . . . . . . . . . . . . . . . . 50
4.1.6 Data Editor . . . . . . . . . . . . . . . . . . . . . . . . 52
4.1.7 Method Tree . . . . . . . . . . . . . . . . . . . . . . . 58
4.1.8 Graphical Output . . . . . . . . . . . . . . . . . . . . . 62
4.1.9 Special Settings . . . . . . . . . . . . . . . . . . . . . . 65
4.1.10 Getting Help . . . . . . . . . . . . . . . . . . . . . . . 67
4.2 Programming Structure of the XQC . . . . . . . . . . . . . . . 68
4.2.1 XClient - The Starting Point . . . . . . . . . . . . . . . 69
4.2.2 User Interfaces . . . . . . . . . . . . . . . . . . . . . . 71
4.2.3 Character User Interface - CUI . . . . . . . . . . . . . 72
4.2.4 Graphical User Interface - GUI . . . . . . . . . . . . . 74
5 XQC/XQS Compared to Other Web Based Statistical Solu-
tions 89
5.1 CGI Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . 89
5.2 “Standalone” Java Applets . . . . . . . . . . . . . . . . . . . . 90
5.3 Java Based Client/Server Computing . . . . . . . . . . . . . . 91
x