New Jersey Institute of Technology Digital Commons @ NJIT
Dissertations Electronic Theses and Dissertations
Spring 5-31-2005
Just-in-time hypermedia
Li Zhang New Jersey Institute of Technology
Follow this and additional works at: https://digitalcommons.njit.edu/dissertations
Part of the Computer Sciences Commons
Recommended Citation Zhang, Li, "Just-in-time hypermedia" (2005). Dissertations. 720. https://digitalcommons.njit.edu/dissertations/720
This Dissertation is brought to you for free and open access by the Electronic Theses and Dissertations at Digital Commons @ NJIT. It has been accepted for inclusion in Dissertations by an authorized administrator of Digital Commons @ NJIT. For more information, please contact [email protected].
Copyright Warning & Restrictions
The copyright law of the United States (Title 17, United States Code) governs the making of photocopies or other reproductions of copyrighted material.
Under certain conditions specified in the law, libraries and archives are authorized to furnish a photocopy or other reproduction. One of these specified conditions is that the photocopy or reproduction is not to be “used for any purpose other than private study, scholarship, or research.” If a, user makes a request for, or later uses, a photocopy or reproduction for purposes in excess of “fair use” that user may be liable for copyright infringement,
This institution reserves the right to refuse to accept a copying order if, in its judgment, fulfillment of the order would involve violation of copyright law.
Please Note: The author retains the copyright while the New Jersey Institute of Technology reserves the right to distribute this thesis or dissertation
Printing note: If you do not wish to print this page, then select “Pages from: first page # to: last page #” on the print dialog screen
The Van Houten library has removed some of the personal information and all signatures from the approval page and biographical sketches of theses and dissertations in order to protect the identity of NJIT graduates and faculty. ABSTRACT
JUST-IN-TIME HYPERMEDIA
by Li Zhang
Many analytical applications, especially legacy systems, create documents and display
screens in response to user queries "dynamically" or in "real time". These documents and
displays do not exist in advance, and thus hypermedia must be generated "just in time" —
automatically and dynamically.
This dissertation details the idea of "just-in-time" hypermedia and discusses
challenges encountered in this research area. A fully detailed literature review about the
research issues and related research work is given. A framework for the "just-in-time" hypermedia compares virtual documents with static documents, as well as dynamic with
static hypermedia functionality. Conceptual "just-in-time" hypermedia architecture is proposed in terms of requirements and logical components. The "just-in-time" hypermedia engine is described in terms of architecture, functional components, information flow, and implementation details. Then test results are described and evaluated. Lastly, contributions, limitations, and future work are discussed. US -I - IME Y E ME IA
y i a g
A isse a io Su mi e o e acu y o ew e sey I s i u e o ec o ogy I a ia u i me o equi eme s o e eg ee o oc o o i oso y i Com u e Scie ce
e a me o Com u e Scie ce
May 5 Co y ig © 5 y i a g
A IG S ESE E APPROVAL PAGE
JUST-IN-TIME HYPERMEDIA
Li Zhang
i Mic ae ie e isse a A iso a e Associa e o esso o I o ma io Sys ems ew e sey I s i u e o ec o ogy
i ce O ia isse a io Co-a iso a e Assis a o esso o Com u e Scie ce ew e sey I s i u e o ec o ogy
ames Ge e Commi ee Mem e a e o esso o Com u e Scie ce ew e sey I s i u e o ec o ogy
imi i eo o a os Commi ee Mem e a e Associa e o esso o Com u e Scie ce ew e sey I s i u e o ec o ogy
a io i a i Commi ee Mem e a e Associa e o esso o Com u e Scie ce U i e si y o o og a
a e Mi a Commi ee Mem e Date Se io esea c e ow o E ec o ics a Com u e Scie ce U i e si y o Sou am o BIOGRAPHICAL SKETCH
Author: Li Zhang
Degree: Doctor of Philosophy
Date: May 2005
Undergraduate and Graduate Education:
• Doctor of Philosophy in Computer Science New Jersey Institute of Technology, Newark, NJ, USA, 2005
• Master of Science in Electrical Engineering Southeast University, Nanjing, China, 1997
• Bachelor of Science in Biomedical Engineering Xi' an Jiaotong University, Xi' an, China, 1992
Major: Computer Science
Publications:
Zhang, L., M. Bieber, D. Millard, and V. Oria. "Supporting Virtual Documents in Just-in- Time Hypermedia Systems", Proceedings of the 2004 ACM, Symposium on Document Engineering, pages 35-44, Milwaukee, Wisconsin, October 2004.
Catanio, J., N. Nnadi, L. Zhang, M. Bieber, and R. Galnares. "Ubiquitous Me ai o ma io a e WYWWΥWΙ i ci e" Journal of Digital Information, Vol. 5(1), 2004.
Zhang, L., and M. Bieber. "Hypermedia in Dynamic Environments", The 7 World Multiconference on Systemics, Cybernetics and Informatics, pages 271-275, Orlando, Florida, July 2003.
Zhang, L., and M. Bieber. "Challenges for Just-In-Time Hypermedia", Hypertext 2002 Advance Program: Demos & Posters, College Park, Maryland, June 2002.
iv is isse a io is e ica e o my ami y o ei o e a su o
ν ACKNOWLEDGMENT
e au o wou ike o e ess e si ce e g a i u e o e isse a io a iso
Mic ae ie e o is ema ka e gui a ce co s a su o a e cou ageme
oug ou is esea c e au o s ee es a ecia io a so goes o e co-a iso
i ce O ia o is e
e au o wou ike o a k ames Ge e imi i eo o a os
a io i a i a a e Mi a o ei a ua e sugges io s o is isse a io a
o se i g as mem e s o e commi ee e au o a so wou ike o a k o
o e o Ga a es M A i a aumik a Ms kec i a i o ei e o so wa e esig a im eme a io
i a y e au o wou ike o e ess e ee es a ecia io o e ami y es ecia y e a e s a e us a o ei o e ai a ie ce a ma y sac i ices
vi TABLE OF CONTENTS
Chapter Page
1 US -I - IME Y E ME IA O E IEW 1
1 1 Mo i a io 1
1 C a e ges o " us -i - ime" y e me ia
1 1 asic Co ce s
1 C a e ges 3
1 3 So u io e us -i - ime y e me ia E gi e 5
1 isse a io Ou i e 5
Y E ME IA 1 O e iew 7
1 1 asic Co ce s o y e me ia 7
1 e e o me is o y
1 3 e e i s a aw acks o y e me ia 1
O e y e me ia Sys ems a e WWW 11
1 O e y e me ia Sys ems 1
Wo Wi e We 1
3 y e me ia u c io a i y 19
3 1 y e me ia u c io a i y O e iew 19
3 asic Co ce s o y e me ia u c io a i y 19
3 3 i ks 1
3 US -I - IME Y E ME IA AMEWO K 33
3 1 y amica y-Ge e a e i ua ocume s s S a ic ocume s 33
vii TABLE OF CONTENTS (Continued)
Chapter Page
3 y amic s S a ic y e me ia u c io a i y 35
3 3 y amic ege e a io 3
3 3 1 ege e a io oce u e 3
3 3 a ame e s o ege e a i g i ua ocume s 39
3 e oca io a e-i e i ica io 1
3 1 oce u e o e oca io a e-i e i ica io
3 a ame e s o e oca io a e-i e i ica io 3
3 5 I y e me ia amewo k
3 5 1 equi eme s
3 5 ogica Com o e s
E A E ESEA C
1 i ua ocume s 9
ocume S uc u e 51
1 ocume S uc u e O e iew 5
M SGM a M 5
3 OM 53
ocume em a es 55
5 ocume S uc u e i I Sys ems 5
3 A a i e y e me ia 5
U ique I e i ie s 59
1 O e iew 59
viii TABLE OF CONTENTS (Continued)
Chapter Page
4.4.2 URI (Uniform Resource Identifier) 61
4.4.3 DOI (Digital Object Identifier) 65
4.4.4 Unique Identifiers in JIT Systems 68
4.5 Object Identification and Addressing Mechanisms 69
4.5.1 Overview 69
4.5.2 HyTime 71
4.5.3 Microcosm, OHP and OHIF 72
4.5.4 XPath and XPointer 75
4.5.5 Object Identification in JIT Systems 77
5 THE JUST-IN-TIME HYPERMEDIA ENGINE 79
5.1 Hypermedia Engine Overview 80
5.2 Dynamic Hypermedia Engine (DHE) 80
5.2.1 Analytical Applications 80
5.2.2 DHE Architecture 81
5.2.3 Component Functionality 82
5.3 The Just-in-time Hypermedia Engine (JHE) 83
5.3.1 JHE Architecture 84
5.3.2 Component Functionality 85
5.3.3 Information Flow 86
6 IMPLEMENTATION 92
6.1 Application 92
ix TABLE OF CONTENTS (Continued)
Chapter Page
6.1.1 NSSDC 92
6.1.2 Magnetosphere Field Models 93
6.1.3 T96 Model 94
6.2 Implementation Details 98
6.2.1 Identifiers 99
6.2.2 JHE Database 100
6.2.3 Hypermedia Service Module (HSM) 101
6.2.4 Application Wrapper Module 104
6.2.5 Regeneration Engine (RE) 109
6.2.6 Selection Manager 111
6.2.7 Document Manager 115
6.2.8 User Interface Module (UIW) 116
6.2.9 Document Translator 120
6.2.10 Tools Used In The JHE Project 121
7 RESULTS AND EVALUATIONS 122
7.1 Dynamic Regeneration 122
7.1.1 JHE Regeneration Results 122
7.1.2 JHE Regeneration Evaluation 128
7.2 Dynamic Hypermedia Functionality 130
7.2.1 User Declared Comment 130
7.2.2 Manual Link 133
χ
TABLE OF CONTENTS (Continued)
Chapter Page
7.3 Relocation and Re-identification 139
7.3.1 Anchor Granularity and Relocation 139
7.3.2 Re-identification 145
7.4 Comparisons with Other Similar Systems 147
7.4.1 Microcosm 147
7.4.2 Freckles 148
7.4.3 00-Navigator 149
7.4.4 Web Vise 150
7.4.5 SFX 151
7.4.6 InfiniTe 152
7.4.7 Comparisons 152
7.5 System Extensibility 154
7.6 Standards Used In JHE 156
7.7 Reflections on the Implementation 156
8 CONTRIBUTIONS 157
9 DISSERTATION BOUNDARIES AND FUTURE WORK 158
9.1 Dissertation Boundaries 158
9.2 Deliverables 158
9.3 Potential Future Work 159
REFERENCES 160
xi LIST OF FIGURES
Figure Page
1 A mi m 7
5 1 E a c i ec u e
5 E a c i ec u e
5 3 isi a ocume 9
5 A a is ay y e me ia co s uc s 91
1 9 mo e que y a e 95
Ca cu a io esu 9
3 A o e e am e o 9 mo e ca cu a io esu 97
9 e o 9
5 S o e o e ie e y e me ia co s uc i o ma io 1
O igi a M " o m" 1
7 I e ce e M " o m" 1 7
A ocume sc ema o 9 mo e 1 9
9 e a i a io oce u e 111
6.10 XPCom component viewer 11
11 Mo i a ce i ica e ma age 11
1 owc a o a c o e oca io a e-i e i ica io 115
13 E a ua e a oi e e essio 11
1 E mai me u 117
15 ookma k se ice me u 11
1 i k se ice me u 119
xii LIST OF FIGURES (Continued)
Figure Page
17 Comme se ice me u 1
7 1 9 ome age i eg a e i o E 1 3
7 A a ookma k o a ca cu a io esu 1
7 3 ege e a e ocume wi c i e io 1
7 A ookma k wi c i e io 1 1
7 5 ege e a e i ua ocume wi c i e io 1 1
7 A ookma k wi c i e io 1 7
7 7 ege e a e i ua ocume wi c i e io 1 7
7 9 ome age 1
7 9 9 ca cu a io esu 1 9
7 1 C ea e a comme 131
7 11 ege e a e i ua ocume wi y e me ia co s uc s a ac e 131
7 1 is o comme s a i ks 13
7 13 is ayi g e comme co e s 13
7 1 A a ew i k w ose es i a io is a U 13
7 15 is o i k i o ma io 135
7 1 a e se o e i k es i a io U 135
7 17 A a i k w ose es i a io is a a c o 13
7 1 is o i k i o ma io 13
7 19 a e se o i k es i a io ( o e a c o ig ig e i e 137
7 A a i k w ose es i a io is a ookma k 137 LIST OF FIGURES (Continued)
Figure Page
7 1 is o i k i o ma io 13
7 a e se e i k o a i ua ocume 13
7 3 C ea e a " oca " a c o 1 1
7 e oca e " oca " a c o s 1 1
7 5 C ea e a "s eci ic" a c o 1
7 e oca e a "s eci ic" a c o 1
7 7 C ea e a "g o a " a c o 1 3
7 e isi e same ocume 1 3
7 9 e isi a o e ocume 1
7 3 A a " o a ue c a ge" a c o 1 5
7 31 e a i a e a c o s 1
7 3 Τ 9C mo e que y a e 155
7 33 Τ 9C ca cu a io esu 155
xiv LIST OF TABLES
Table Page
3 1 y amica y-ge e a e s S a ic ocume s 3
7 1 E a ua io s o y e me ia E gi es 15
xv CHAPTER 1
JUST-IN-TIME HYPERMEDIA OVERVIEW
"Just-in-time" (JIT) hypermedia research introduces new concepts and encounters problems that are different from traditional hypermedia research. Section 1.1 motivates this research. Section 1.2 briefly discusses basic concepts and challenges met in this research area. (These issues will be discussed in Chapter 2 in detail.) Section 1.3 gives a brief description of the proposed "just-in-time" hypermedia engine. Section 1.4 presents the dissertation outline.
1.1 Motivation
Many analytical applications, especially legacy systems, create documents and display screens in response to user queries "dynamically" or in "real time". These documents and displays do not exist in advance, and thus hypermedia must be generated "just in time"— automatically and dynamically.
Suppose an analyst wants to determine projected profits for different sales levels in her company. She performs the analysis within a sales support application, and makes comments on each resulting profit calculation. A few days later when preparing her final report, she knows that she will need to include the calculation results and comments. She wishes to return to them without having to remember the input parameter values for each and then manually re-performing each calculation. Therefore, she creates a bookmark to the display screen containing each calculation result before discarding it. Invoking each bookmark later causes the sales support application to re-execute its calculations
1 au oma ica y a e y e me ia i e ace o e oca e e comme s i e a ica io s
ew y e-ge e a e is ay
1.2 Challenges of "Just-in-time" Hypermedia
is sec io i o uces asic co ce s o " us -i - ime" y e me ia a ie y esc i es c a e ges i is esea c a ea
1.2.1 Basic Concepts
Documents and Elements: A y e me ia sys em usua y e a es use s o a i ks sema ic i o ma io o ocume s (s a ic o y amic a e eme s A e eme i a
ocume is a a i a i y se ec e o io o e ocume
Hypermedia Functionality: y e me ia sys ems i c u e ma y ea u es o e use s o
a iga e o u e s a i o ma io we ese ea u es a e ca e y e me ia u c io a i y
A c o a a ea wi i e co e o a ocume w ic is e es i a io o sou ce o a i k
Virtual Documents and Virtual Elements: A i ua ocume is a ocume o w ic
o e sis e s a e e is s a o w ic some o a o eac i s a ce is ge e a e a u
ime (Wa e s 1999 E eme s i a i ua ocume a e ca e i ua e eme s
Dynamic Hypermedia Functionality: e y e me ia u c io a i y associa e wi
y amica y - ge e a e ocume s a e eme s is ca e y amic y e me ia
u c io a i y A c o s associa e wi y amic y e me ia u c io a i y mus e
e e mi e i i ua ocume s w e e ocume s a e ge e a e i ua ocume s 3
a a e e su ec s o y amic y e me ia u c io a i ies o o e is e ce w e e
ocume is ei g is aye o e com u e sc ee
Dynamic Regeneration: A ew i oca io o e y amica y - ge e a e i ua
ocume is ca e y amic ege e a io
Relocation and Re-identification: o i e i y a o ma y - i e i ie e eme i a
ege e a e i ua ocume is ca e e-i e i ica io o oca e a o ma y - c ea e a c o i a ege e a e i ua ocume is ca e e oca io
1 Challenges
A I y e me ia sys em is i e e om a a i io a y e me ia sys em i a i a s
y e me ia u c io a i y o y amica y - ge e a e i ua ocume s w i e a i io a
y e me ia sys ems usua y ea wi s a ic ocume s e ma o c a e ges e cou e e i I y e me ia esea c a e y amic ege e a io e oca io a e- i e i ica io A o e iew o ese c a e ges is gi e i Sec io 1 1 a 1
e ai s wi e iscusse i C a e
1.2.2.1 Dynamic Regeneration. I a a y ica o com u a io a a ica io s
ocume s o o e is i a a ce ey a e ge e a e w e use s o que ies o e ecu e some comma s W e e wi ows c ose ese ocume s o o ge e is I a use a s some comme s o a ocume e ime w e e ies o isi e comme s e
i ua ocume a was a o a e s ou e e-ge e a e Some We sys ems
ege e a e a a ysis sc ee s y s o i g a e e a a ame e s i e i ua ocume s
U (U i o m esou ce oca o u ma y We - ase a o -We ase egacy sys ems a e o suc mec a ism O e We sys ems o o a ow U s wi e ai e
a ame e s o secu i y o o e easo s W e e use ookma ks a e u s o i s
U e sys em e u s e use o e ome age o e i i ia i u age e I
y e me ia sys em mus o i e au oma ic ege e a io wi ou aski g e use o
ee e a ame e s ecause a i ua ocume oes o a e a i e ame a a s eci ic
oca io o s o e e i e co e y amic ege e a io equi es a u ique a e sis e i e i ie o e e e ce eac i ua ocume y amic ege e a io a so equi es a c i e io a oce u e o eci e w e e e e-ge e a e ocume is same as e
e ious y ma ke ocume C a e 3 wi iscuss i e ai e equi eme s o
y amic ege e a io e oce u e o o ege e a io a e i o ma io ee e o ege e a io
1 Relocation and Re-identification. W e a i ua ocume is
ege e a e e i ua ocume s s uc u e a co e cou e c a ge I cou a so
e ossi e a i ua e eme s i e ocume a e c a ge I a use as u some a c o s o e i ua ocume e osi io a co e o e a c o s cou c a ge I is ecessa y o i e oca io o e e e i e a c o s i e i ua ocume a
eci e w e e e co e is same as e e ious y ma ke o e is is ca e e-
oca io a e-i e i ica io Mo eo e w e a a y ica a ica io s ge e a e ew que y esu s e I y e me ia sys em s ou e oca e a e-i e i y e a c o s o k ow e eme s i e o que y esu s e- oca io equi es e i e a e icie mec a isms o eco e oca io a co e o a c o s e-i e i ica io equi es a c i e io o e a i a e e i ua e eme s a some i o ma io a ou e i ua e eme s a e ee e C a e 3 iscusses a e a o e as ec s o e- oca io a e- i e i ica io i e ai 5
1.3 Solution: the Just-in-time Hypermedia Engine
The Just-in-time Hypermedia Engine (JHE) executes as a middleware between an application and its user interface, providing additional hypermedia navigational, structural and annotation functionality, with minimal modification to the application.
JHE should have the following functions to supplement hypermedia functionalities for the "just-in-time" environment:
(1) JHE assigns unique, persistent identifiers for documents, elements and anchors in the documents;
(2) JHE stores links, comments, etc., in an external linkbase;
(3) JHE does the regeneration by intercepting the messages between the user interface and the applications.
(4) JHE relocates and re-identifies the anchors in the documents efficiently.
"Wrappers" need to be written for each application in order to integrate them with the engine architecture.
1.4 Dissertation Outline
Chapter 2 gives a detailed literature review of hypermedia research areas. Chapter 3 discusses the "just-in-time" hypermedia framework. Chapter 4 describes related research areas including: virtual documents; WWW standards; unique identifiers; object identification and addressing mechanisms; and document structure recognition. Chapter
5 proposes the Just-in-time Hypermedia Engine (JHE), in terms of architecture, data formats, and flowcharts. Chapter 6 describes implementation details. Chapter 7 gives test results and evaluations. Chapter 8 discusses contributions of this research. Chapter 9 discusses the main issues and problems of this research, and future research work. CHAPTER
HYPERMEDIA
y e me ia is a co ce a e cou ages au o s o s uc u e i o ma io as a associa i e e wo k o o es a i e e a i g i ks ( ie e 1997 is c a e esc i es
asic co ce s o y e me ia y e me ia e e o me is o y o e y e me ia sys ems a e Wo Wi e We (WWW a y e me ia u c io a i y Sec io 1 gi es a o e iew o y e me ia Sec io 1 1 esc i es e asic co ce s o
y e me ia i c u i g y e me ia i ks a o es Sec io 1 esc i es e
y e me ia e e o me is o y om 19 5 w e us i o uce e i ea o
y e me ia o e s a e o e a e e o me og ess I esc i es e ea ie
y e me ia sys ems i 19 s a 197 s w ic a e mai ame- ase e o y sys ems
u i g 19 s ma y y e me ia sys ems we e ui o wo ks a io s a y e me ia
esea c g ou s s a e o wo k o i e o e a i i y o i e e y e me ia sys ems w ic ea s o e eme ge ce o o e y e me ia sys ems Sec io 1 3 iscusses
e e i s a aw acks o y e me ia sys ems Sec io gi es a o e iew o o e
y e me ia sys ems a e WWW Sec io 1 esc i es co ce s o o e
y e me ia sys ems i s og ess a e O e y e me ia Sys em Wo ki g G ou
(O SWG O S esea c as ma e sig i ica og ess si ce 19 s Si ce ea y 199 s
e Wo Wi e We as e i s u ic y acce e y e me ia sys em c a ge eo e s
i es g ea y a ac i a e muc esea c wo k i WWW e a e ie s ecause o e
aw acks o a i io a WWW sys ems ma y y e me ia sys ems we e ui ase o
e We yi g o e a ce e a i io a WWW sys ems u c io a i y
7
As me io e a o e o es a i ks a e asic com o e s o y e me ia sys ems y e me ia sys ems s ou a e mo e u c io s/ ea u es o e a e use s o iew a ma age ocume s ese ea u es a e ca e y e me ia u c io a i y Sec io 3
iscusses y e me ia u c io a i y Sec io 3 1 gi es o e iew o y e me ia
u c io a i y Sec io 3 3 i o uces asic co ce s o y e me ia u c io a i y suc as o e a c o a o a io a se ec io Amo g em i ks a e e mos im o a
ea u e i ks e ese e a io s i s e wee o es i ks ca e s a ic o y amic; au oma ic o ma ua ; em e e o e e a ; u i i ec io a o mu i i ec io a ; a sema ica y y e Sec io 3 3 iscusses i e e as ec s o i ks os a co s o
i e e a i u es I a so esc i es i e e i k se ice sys ems a e i k i eg i y o em
A us -i - ime y e me ia sys em is a y e me ia sys em a ca su eme
y amica y-ge e a e i ua ocume s wi y e me ia u c io a i ies A I sys em
o i es a We i e ace o a ica io s a i is ui ase o e WWW
ec o ogies i o e y e me ia sys ems a e WWW ca e e u o a I sys em
2.1 Overview is sec io iscusses e asic co ce s o y e me ia a i s e e i s a aw acks
e i ese s a ie o e iew o y e me ia sys em is o y
2.1.1 Basic Concepts of Hypermedia
y e me ia is a co ce a e cou ages au o s o s uc u e i o ma io as a associa i e e wo k o o es a i e e a i g i ks ( ie e 1997 y e me ia
esea c e s iew e e ms h p rt xt a h p r d as sy o ymous a use em 8 i e c a gea y y e me ia omi a y a ies y e e co ce s o mu i e me ia A
y e e sys em is ma e o o es (co ce s a i ks ( e a io s i s A o e usua y
e ese s a si g e co ce o i ea I ca co ai e g a ics a ima io au io i eo images o og ams I mos y e me ia sys ems a o e usua y is a ocume I ca e sema ica y y e (suc as e ai o osi io co ec io summa y o se a io issue
e e y ca yi g sema ic i o ma io ( ao 199 o es a e co ec e o o e o es
y i ks i ks e ese e a io s i s e wee wo o es
2.1.2 Development History
e co ce o y e e i s a ea e i a e a us s a ic e "As we may i k" i
19 5 us e isio e a "meme " mac i e w ic amo g ma y o e i gs cou assis e scie is i e e o i g associa i e i e es o " ai s" oug a co ec io o
ocume s e e e o me o y e e sys ems as e o e oug ma y s ages
e ea ies y e e sys ems aime o o i e s ee y access o i o ma io y c oss- e e e ci g a associa i e i e i g Mos sys ems we e mai ame- ase e o y sys ems o e i g i o ma io ame y ame suc as S/Augme (E ge a
19 ESS ( a am 19 a OG (McC acke 19 S/Augme was e
i s y e e sys em e e o e i 19 s y oug as E ge a s g ou I
S/Augme o es we e o ga i e i o i es e e e ce i ks e e a use o mo e
om o e i e o a o e ESS was e e o e y a am i 19 w ic was a i e
e ie i g a e i i g sys em u i g o a I Μ/3 mai ame OG was a a ge
a a ase co sis e o ames w ic was e e o e a Ca egie-Me o U i e si y i
1975 A ame i OG co sis e o a i e a esc i io a i e wi s a a OG comma s a a se o me u i ems ea i g o o e ames ese sys ems a su o 9 for multiple users sharing the hypermedia information network. Nodes were un-typed, without supporting composites.
In the latter part of the 1980s, workstation and operating system technology had advanced to the stage that it was possible to start conducting research into the ideas originally conceived by Bush, Engelbart and McCracken. Research-oriented systems such as Notecards (Halasz 1988), KMS (Akscyn 1988), Neptune (Desisle 1986), gIBIS
(Conklin 1988) and Intermedia (Yankelovich 1988 and Haan 1992) began to appear.
Notecards (Halasz 1987) is a hypermedia system from the 1980s, aimed at easing the task of idea processing. Idea processing is divided up in three phases: asquisition, analysis and exposition. Notecards has four basic objects: notecards, links, browsers, and fileboxs.
Navigating structure in Notecards can be done in either of two ways. It is possible to follow links from card to card, at each card deciding which link to follow. It is also possible to create an overview browser for some subnetwork, and then traverse the links from the browser to the referenced cards. In (Halasz 1988), experience with Notecards lead to suggestion of seven issues that later became a milestone in hypermedia. KMS
(Knowledge Management System) was developed based on ZOG. Though KMS included a GUI (Graphic User Interface), it still remained a text-based system. It was intended to be a collaborative tool, in that users could modify the contents of a frame and the changes would be immediately visible to others through dynamically updated links. gIBIS is an
Issue Based Information System that is designed to facilitate the capture of early design deliberations. gIBIS offers argumentation support through issue, position and argument objects. The system makes use of an overview picture of the complete structure, with an indicator showing where the user is. These systems are similar in concept to the earlier 0 mai ame- ase sys ems I a i io ey su o e g a ics o es a ey a mo e a a ce use i e aces
eyo ese we -k ow sys ems e e a e ma y o e esea c o ie e
o o y e sys ems some o w ic a e es ecia y we ocume e suc as a e is (S o s
19 9 a E e e ( a a 1991 A so e e a e some y e me ia e e e ce mo e s
e e e Mo e ( a as 199 is a we - ocume e y e me ia e e e ce mo e
o o y e sys ems ike e ise (G ø ak 1997 a M a e ase i e e mo e
y e e A s ac Mac i e ( AM (Cam e 19 7 is a o e ig e e y e me ia mo e
I e a e 19 s e y e me ia esea c commu i y e e o e amo gs o e s wo se a a e esea c ea s o e ocusi g o O e y e me ia Sys ems (O S a o e o A a i e y e me ia (ΑΗ A o o wo k as ee o e i ese a eas si ce
e w ic wi e iscusse i e ai a e I e ea y 199 s e Wo Wi e We
(WWW a ea e as e i s o e a is i u e y e me ia sys em I gai e i s
o u a i y ue o i s sim ici y a ge e a i y Muc e o as ee u i o e WWW
esea c a eas a sig i ica og ess as ee ma e si ce e I wi e iscusse i
Sec io
2. . e e i s a aw acks o y e me ia
y e me ia sys ems e a e use s o a i ks a comme s o ocume s i a way simi a o uma u e s a i g o e am e a ea e usua y ig ig s o u e i es some wo s se e ces o a ag a s i a ook o e im/ e o emem e o u e s a e co e s Α y e me ia sys em ca e use s o a iga e ocume s y usi g gui e ou s (a o e e se o o es o ocume s o o e iews (a o e iew ma 11 of nodes). Hypermedia systems supply tools such as search to help users understand and organize the documents in information systems.
In summary, the benefits of adding hypermedia functionality to information system applications are that hypermedia provides contextual, navigational access for viewing information and that it represents knowledge in a form relatively close to the cognitive organizational structures that people use.
Conklin (1987) identifies two major dangers of free-formed hypermedia access within an associative network: d r nt t n and n t v v rh d. r nt t n occurs when readers lose track of their position within the hypertext web while traversing links. C n t v v rh d occurs when readers feel overwhelmed with too many choices of where to navigate next. While many hypermedia researchers believe that disorientation and cognitive overhead are problems inherent in hypermedia, proper implementations of advanced hypermedia features (such as guided tour or overviews) will alleviate these problems, as well as provide readers with a rich information environment. (Bieber 1997)
2.2 Open Hypermedia Systems and the WWW
Hypermedia research has many fields that address different aspects of hypermedia. It i c u es O e y e me ia Sys ems (O S A a i e y e me ia (ΑΗ s a ia
y e me ia o ec -o ie e y e me ia Wo Wi e We (WWW e c Α " us -i -
ime" ( I y e me ia sys em is a y e me ia sys em a ca a y e me ia
u c io a i ies o y amica y-ge e a e i ua ocume s A so i ca a a We i e ace o a a y ica a ica io s O S a WWW sys ems a e iscusse i is 2 c a e A a i e y e me ia sys ems ge e a e y amic ocume s ase o use mo e s ΑΗ wi e iscusse i C a e
2.2. O e y e me ia Sys ems
2.2. . O e iew. e i s y e me ia sys ems we e om a a c i ec u a
oi o iew mo o i ic sys ems e ec e as a si g e ocess com i i g e use i e ace i ki g mec a ism a i o ma io s o e i o e og am is ma e e
(mai y a iga io a y e me ia aci i ies i e i e si ce i o ce e use s o use e em e e use i e aces
I e a e 19 s O S esea c ecame a im o a a ea i y e me ia
esea c O S esea c a esses e issue o i eg a i g y e me ia u c io a i y i o e is i g a ica io s i e com u i g e i o me A o e y e me ia sys em is
y ica y a mi ewa e com o e i e com u i g e i o me o e i g y e me ia
u c io a i y o a ica io s i e e e o ei s o age a is ay u c io a i y Usi g
e se ices o a O S e is i g a ica io s i e com u i g e i o me ca ecome
" y e me ia e a e " us su o i g i ki g o a om i o ma io ma age y e a ica io wi ou a e i g e i o ma io i se o ecome " y e me ia e a e " a ica io s mus e a e o commu ica e y e me ia eques s o e O S (O SWG
1997
2.2. .2 Ea y Ge e a io O S Sys ems. Ea y ge e a io O S sys ems i c u e Mic ocosm ( a is 199 S 3 (Sc ase 199 C ime a (A e so 199 e c
Mic ocosm uses a " i e " mo e o su o o e y e me ia u c io a i y A c o ac i a io a i k a e sa a e im eme e as messages assi g oug a c ai o
i e ocesses eac o w ic ca ecei e messages a ake a o ia e es o ses (suc 13 as o wa i g o e e i e i c ai Mic ocosm su o s "ge e ic i ks" a c o e o a y occu e ce o a s i g i a ocume s a "com u e i ks" w ic uses e
e ie a ec iques o com u e e i k es i a io y amica y us su o i g ue co e - ase y e i ki g
S 3 uses a ocess- ase mo e is sys em as a e y ge e a mo e i w ic a c o s a i ks a e emse es ocesses a i k o e a io s co es o o commu ica io s e wee ese ocesses a a ici a i g a ica io s A ica io s kee ack o e oca io s o e sis e se ec io s i ei ocume s
2.2.1.3 OHSWG. Si ce i e e O S sys ems use i e e a c i ec u e a a a mo e s ey ack ese a io i e o e a i i y s o age i e o e a i i y a sys em i e o e a i i y I was c ucia o a e commo gui e i e a s a a s o i e o e a io e wee O Ss a a ica io s a eques y e me ia se ices e
O e y e me ia Sys ems Wo ki g G ou (O SWG was o me i 199 o a ess
ee key issues e i i g o e y e me ia sys ems ( e sce a io su g ou e i i g o e i k se ices ( e o oco su g ou a e i i g a O S e e e ce a c i ec u e
( e e e e ce a c i ec u e su g ou
Si ce 199 O S sys ems a s a a s a e ma e g ea og ess i e as ec s o e O e y e me ia o oco ( a is 1997 O S sys em a c i ec u e a O S a a mo e (G ø aek 1997 I 199 a s a a a a mo e (w ic a e ecame O M
(Mi a o o e y e me ia s uc u es was o ose I i c u es e O SWG
a iga io a a a mo e s a ia a a mo e a a o omy a a mo e 4
In the late 1990s, OHS and WWW research became intertwined fields; most OHS systems built their systems to supply rich hypermedia functionality for the WWW, such as WebVise (Grønbaek 1999).
Open hypermedia systems is now a relatively mature area making significant progress in the area of standardization and the support of interoperability between open systems, addressing some earlier concerns regarding the definition of intermediate formats. Difficulties remain in providing common interfaces across the wide range of applications and participating open hypermedia systems (Cunliffs 2000). Recent OHS work includes Web technology (using XLink as syntax to support Web services), hypermedia concepts (such as asynchronous linking) and open hypermedia infrastructure
(security, authentication, etc) (OHS 2002).
A JIT system is a middleware between applications and the viewer. The ideas and methods of OHS systems, such as data models and link services, could be helpful in developing JIT systems.
2.2.2 Wo Wi e We
2.2.2. WWW is o y a aw acks. Tim Berners-Lee proposed the
WWW research project (originally as an information system for the particle physics community) at CERN in Switzerland in 1989. The first Web server and browser were established on December 1990. The W3C consortium (W3C) was established in 1994 to improve WWW development and conclude WWW standards. Marc Andersen developed
Mosaic for NCSA in 1994, which is the first Web browser to capture the public's imagination. In 1995, Digital Corp. made AltaVista (a search engine) available to the public. The World Wide Web (WWW) (Lee 1992) is the largest distributed hypermedia 15 sys em i use I makes use o a a o ma s ( o e am e M a access o oco s
( o e am e w ic a e o e e e si e a s a a WWW is a is i u e
y e me ia sys em com i i g e co ce o y e i ks (associa i e owsi g y
o owi g i ks o e a e i o ma io wi mu ime ia ( e image au io i eo e c
oug i s U (U i e sa esou ce oca o mec a ism WWW ca e ese i ks o a y ocume o a y We Go e o se e wo wi e e CGI (Commo
Ga eway I e ace sc i i e ace a ows WWW se e s o s a a i a y a ica io
og ams o e am e i ki g i o e e a a a ases o im eme i g com e sea c a go i ms
es i e i s o u a i y a su o o g o a is i u io e a i io a WWW sys em as se e a weak esses w e e ami e om wi i e ic co e o
y e me ia sys em (A ews 1995
(1 M uses em e e a o e-way i ks Em e e i ks a e ma y isa a ages a e e a i ks w ic is iscusse i e ai i C a e 3
( S a a y e me ia ea u es suc as gui e ou s a o e iews a e o o i e au oma ica y A o a io was o ce a ea u e i Mosaic u ake away a e
(3 WWW as o a i e sea c aci i ies u e ies o e e a sea c e gi es
( e e i i i y o i e y CGI is ac ie e a g ea cos e u i o mi y o e i e ace isa ea s; i e e WWW se e s e a e i e e y — esu i g i e " a ka isa io " (acco i g o e e so o e We i o i e e e "W3 Em i es"
(5 e We o ay is e y muc " ea -o y" i e se se a i o ma io o i e s e a e a a se s i w ic i o ma io co sume s ca ge e a y o y owse
( A oug i s U mec a ism e ows WWW i e ms o um e o se e s i is o sca a e i e ms o um e o use s W e e e a e oo ma y c ie s co ec i g o o e se e a ic am occu s o e I e e 16
e Wo Wi e We ge s i s o u a i y ue o i s sim ici y e e oug is sim ici y i gs ma y e icie cies Si ce e We oes o a e ic y e me ia
u c io a i y some eo e e e a gue w e e i is a ea y e me ia sys em A o o e o s a e ee ma e o e ic y e me ia u c io a i y o e WWW si ce i s eme ge ce
Web Based Hypermedia Systems. o o e come e aw acks oug u y e ea ie WWW sys ems o e We ase y e me ia sys ems a e ee
e e o e suc as y e -G (A ews 199 ( a e y e Wa e a y e isco (Wii
199
y e -G is a mu i-use mu i- o oco s uc u e y e me ia i o ma io sys em w ic u s as a c ie -se e a ica io o e I e e (A ew 199 o e a e ia e e iso ie a io associa e wi ecomi g " os i y e s ace" y e -G
o i es ee c ose y cou e o ogo a a iga io a mec a isms s uc u i g
y e i ks a sea c e ig cou i g a ows c ie s o co e a e sea c esu s i k ma s a s uc u e o e iews o i i g a owe u a iga io y e -G g ou s
ocume s i o agg ega e co ec io s w ic may emse es e o g o o e co ec io s
a iga io may e e o me ow oug e co ec io ie a c y access ig s assig e o a co ec io - y-co ec io asis a e sco e o sea c es es ic e o a
a icu a se s o co ec io s i ks i y e -G co ec a sou ce a c o wi i o e
ocume o ei e a es i a io a c o wi i a o e ocume a e i e ocume o a co ec io ocume s a co ec io s a e a associa e se o a i u es (au o i e keywo s e c w ic may e sea c e o i c u i g oo ea com i a io s a e m
u ca io u e (co e sea c aci i ies i c u e ec o a u y oo ea que ies
HyperDisco (Wiil 1996) provides an extensible object-oriented hypermedia integration model supporting inter-tool linking, computation, concurrency control, notification control, version control, access control, search and query, and various other features. HyperDisco provides two distinct layers of hypermedia functionality: integration model layer and data model layer. HyperDisco provides an extensible object- oriented data model with a set of general hypermedia object types: anchor, node, link and composites. All instances in HyperDisco have a unique object identifier (OID). The link class supports a very general multiheaded (n-n) links. Links have a direction, but can be traversed in both directions. Links maintain two lists of endpoints (to and from). A link endpoint can be one of three types: static, dynamic (computed) or dangling. HyperDisco supports both content and structure based queries as a supplement to navigational information retrieval (browsing and link traversal). Boolean operators such as NOT,
AND and OR and control structures such as IF, COND, and CASE are used to glue basic search operations together.
A JIT system is a Web-based hypermedia system, trying to provide hypermedia functionality for dynamically generated virtual documents. Hyper-G and HyperDisco provide many hypermedia functionalities for Web systems, technologies or methods from them or other Web-based open hypermedia systems could be helpful to JIT system design.
2.2.2.3 W C a e Sema ic We . In October 1994, Tim Berners-Lee founded the World Wide Web Consortium (W3C) at the Massachusetts Institute of Technology,
Laboratory for Computer Science, in collaboration with CERN, where the Web originated, with support from DARPA and the European Commission. Goals of W3C for 18
e We i c u e omo i g u i e sa access sema ic We a We o us U i e sa access is o make e We accessi e o a y omo i g ec o ogies a ake i o accou e as i e e ces i cu u e a guages e uca io a i i y ma e ia esou ces access e ices a ysica imi a io s o use s o a co i e s e sema ic We is
e e ese a io o e a a wi we - e i e mea i g o e Wo Wi e We e a i g com u e s a eo e o wo k i coo e a io We o us is o gui e e
We s e e o me wi ca e u co si e a io o e o e ega comme cia a socia issues aise y is ec o ogy Si ce 199 e W3C as ma e g ea og ess i
omo i g a e e o i g e isio o e WWW u u e i esig i g We ec o ogies a s a a i i g We ec o ogies
im e e s- ee o ose e "Sema ic We " a e 1999 WWW mee i g
e sema ic We is a We a i c u es ocume s o o io s o ocume s
esc i i g e ici e a io s i s e wee i gs a co ai i g sema ic i o ma io i e e o au oma e ocessi g y com u e s e W3C as o ose a se ies o
a s a ou me a a a s a a s o We suc as M (e e si e Ma ku a guage
( esou ce esc i io amewo k S G (Sca a e ec o G a ics ( e aio o
1 a SMI (Sy c o i e Mu ime ia I eg a io a guage ( osc ka 199
Wi e i o uc io o M a a ew e e o me s suc as Sc ema a AM +OI ( a me e 1 e Sema ic We is a i y aki g s a e
(Osse ugge iscusses cu e Sema ic We i as uc u e w ic is com ose o ocume e ese a io a guage (suc as M S G a SMI k ow e ge
e ese a io a guage (suc as a Sc ema a e u e yi g M
a guage A ica io s a use is i as uc u e i c u e W3C s a o m o I e e 19
Co e Se ec io ( ICS (Mi e 199 a o m o i acy e e e ces o ec ( 3
(C a o a e u i Co e (Wei e 1995
O e o ec i e o I sys ems is o o i e sema ics o a ica io s
ec o ogies i e sema ic We cou e us e e o ΙΤ sys ems o e am e me a a a a e use o e-i e i y i ua ocume s a e eme s
2.3 Hypermedia Functionality
2.3.1 Hypermedia Functionality Overview
y e me ia sys ems i c u e ma y a iga io a o a io a s uc u a ea u es w ic
ake a a age o e o e a i k s uc u e o su o au o s a ea e s ese
ea u es a e ca e y e me ia u c io a i y
ey cou e c assi ie as o ows
Hypermedia Structuring Functionality: y e me ia s uc u i g u c io a i y i c u es g o a a oca o e iews; ai s a gui e ou s; o e i k a a c o y i g; as we as keywo s a o e a i u es o a o ese
Hypermedia Navigational Functionality: a iga io a u c io a i y e com asses access a gi g om i o ma io e ie a o owsi g is i c u es s uc u e- ase que y (co e - ase sea c ; is o y- ase a iga io ; i- i ec io a i ki g; y amic a com u e i ki g; a ocess e ac me o e ecu io oug i k a e sa
Hypermedia Annotation Functionality: A o a io u c io a i y i c u es use - ec a e i ks comme s a ookma ks e c
2.3.2 Basic Concepts of Hypermedia Functionality ( ie e 1997
o e a u i o i o ma io A so k ow as a ame (KMS o ca ( y e ca o eca s
Link Anchor: a a ea wi i e co e o a o e w ic is e sou ce o es i a io o a i k 20
i k Ma ke : e ysica ma ki g a s ows e oca io o a i k a c o w e is aye is is a so ca e a " o s o " o some imes " u o "
i k e e a io s i e wee wo a c o s s o e i e same o i e e a a ase
i k a e sa : e ac i i y o isi i ks
Se ec io a a ea i e sc ee w ic co ai s e a a (suc as s i g image o a a c o
iewe a og am o is ay a ocume o me ia
A o a io : e i ki g o a ew comme a y o e o a e is i g o e
a / ai a o e e se o o es o a c o s
G o a a oca O e iew: O e iew iag ams o i e ic u es o eig o oo o es G o a o e iew iag ams o i e a o e a ic u e a ca a so se e as a c o s o oca o e iew iag ams oca o e iew iag ams o i e a i e-g ai e ic u e o e oca eig o oo o a o e
Gui e ou : A gui e ou is a sys em-co o e a a ca e e e e a e i e a e use s wi
o e y es: o e y es o i e sema ics c a ac e i i g a o e a i s co e
i k y es: A i k y e e ese s e sema ics o e e a io s i e wee e sou ce a e es i a io o a i k (A a 199
A c o y es: e sema ic y es o a a c o
o e i k A c o A i u es: i a i io o y es o e sema ics ca e a ac e o o es/ i ks/a c o s suc as a e s ames keywo s o imes am s ( ie e 1997
Co e ase Que y: sea c a o e o e we (a associa i e e wo k ase o e o e co e y usi g keywo s (i co u c io wi oo ea o e a io o weig i g o wo s ase o ei s a is ica o e ies
S uc u e ase Que y: i e e om a i io a e s i g sea c o o e co e s uc u e- ase que y is ase o o e a i k a i u es
ack acki g: ack acki g isi s e ious y isi e o es ose e g (199 o es ee easo s o ack acki g o e iew e co e o a e ious y isi e o e o eco e om a i k c ose i e o ; a as a o u oi g Co ce ua y owe e ack acki g i e s om undoing i a ack acki g e u s e ea e o a e ious y isi e o e i i s cu e s a e 21
History List: A is o y is is a o e e is o o es a we e e ami e i a a icu a sessio
Bi-directional (Multi-directional) Linking: i ks ca e o owe i ei e (mu i e i ec io y use c oice
Arbitrary Jump: A i a y um s o go os ca e o i e e a i g use s o go o a y o e i e sys em
Landmark: " a ma ks" o omi e o es a e o es a ca a ways e accesse om a yw e e i e sys em a ma ks a e usua y o i e y a au o as o ose o ookma ks w ic a e c ea e y e e use ( ea e
Bookmark: A ookma k is is simi a o a is o y is e ce a a ookma k is ace y e ea e A so a ookma k ca e see as a si g e-e e i k sa e y e ea e e ce a ookma k is is sma e mo e ma agea e a mo e e e a o e use
Embedded Menu: Em e e me us as o ose o e ici me us a ow e use o se ec a i em em e e wi i e e o a o e a ca e se ec e usi g a ouc sc ee cu so keys o mouse oi e
Transclusion: e e so o ose a sc usio s as a mec a ism o a i g e e ac same o ec ( ocume co e i c u e i mu i e aces A a sc usio is o a co y u a e e same e ac i s a ce (o a oi e o a i s a ce
Warm/hot Links: Wa m a o i ks a e e a io s i s a c ea e a c a e e wee e wo e oi s oug w ic a a ows om o e ocume o e o e Wa m a o i ks a e o oi e s u ac ua co ies o e a a w ic ca u a e au oma ica y Wi warm links, use s e ici y ask o u a e e o e co e Wi hot links, co e is e i ie a u a e au oma ica y as soo as e a a a e is aye
3 3 i ks
i ks co ec e a e co ce s o o es ey ca e i- i ec io a us aci i a i g
ackwa a e sa s i ks ca a so e sema ica y y e (suc as s eci ica io i k e a o a io i k mem e s i i k o osi io i k a o e s s eci yi g e a u e o
e a io s i (Co k i 19 7 i ks ca e ei e e e e ia ( o c oss- e e e ci g
u oses o ie a c ica (s owi g a e -c i e a io s i s i ks a e ma y i e e as ec s (suc as s a ic y amic au oma ic a e e a w ic wi e iscusse i e
es o is sec io
2.3.3.1 Static vs. Dynamic Links. S a ic i ks a e i ec e sis e co ec io s
om o e o e o a c o o a o e y amic i ks o e o e a a e com u e eac
ime a a em is ma e o a e se em
e s a ic i ks su e om a a ie y o o ems (May ie 1997 ese i c u e
• a g i g i ks w e a i k oi s o a o e a is su seque y mo e o e e e a i k ecomes s a e; a em s o a e se i wi ai
• I e essi e ess some co e io a sys ems ack i k sema ics i o ma io E e i sys ems a o o i e i k y es i e um e o i k y es is se i a a ce e e i o ma io co e a ca e a ac e o a i k is es ic e o e e i e se
• E e si e co s uc io ma ua y co s uc i g i ks is ime-co sumi g a e e si e
• I e i i i y ma ua i ks a e c ea e o ce a a e e ea e i e ; ey a e u a e o ea a ge emse es o sui e ee s o e mome
• u ica io e sema ic k ow e ge im ici i a a icu a i k o i k y e ca o easi y e euse o ge e a i e
• I e e a ce W e a o e s co e c a ges o o e co i io s c a ge e i k may o o ge a i
y amic i ks a e c ea e a u - ime a e a ei g ge e a e ea ie ( e- com u e i ks O e a oac o y amism i y e e ocuses o com u i g i ks
ase o e a io s i s o simi a i ies e wee e s o assages o e I is a oac
e i k is o e i e as a oi e om o e y e e o e o a o e u a e as a que y a ea s o a i e e o e ( o e 1999 e-com u e i ks ca e co s uc e a a y ime w e eas y amic i ks a e com u e a e mome ey a e
equi e (As ma 1997 A y amic i k ca ake i o accou e s eci ics o e 3 cu e use i e ac io e que y mig e ase o a com i a io o e owsi g
is o y use o i e co e o e cu e ocume e c
Com a e o s a ic i ks y amic i ks a e mo e e i e a s a ic i ks
y amic i ks a e y amica y com u e acco i g o e u e yi g e a io s i s
e wee o es o e eme s Si ce y amic i ks a e com u e a e ime w e use s
eques o o so e e is o ee o u ica e e i ks ma ua y a i is o ime co sumi g O e o e a y amic i ks a so ca su e om e a g i g i k
o ems y amic i k o uc io owe e ca e ec a a g i g i k o em w e i occu s a ca gua a ee a o a g i g i ks a e is aye y amic i ks ca a ow
i ks o e c ea e om a o ma e ia a e i k au o oes o co o y o e ayi g e i k wi i e ocume se o a owse W e a o e s co e c a ges o o e co i io s c a ge y amic i k o uc io as e o e ia o e ec
a e i k is o o ge a i
A a ages o y amic i ks i c u e a sim i ie i e ace o sea c
u c io a i y e uce au o i g e o a g ea e o o u i y o cus omi a io ase o e cu e use s i e ac io is o y o s eci ic ask co e A a i io a e e i is
ec ease cos o mai e a ce owe e isa a ages i c u e com u a io o eac
i k a u - ime (i s ea o usi g s o e e-com u e i ks o e -com e e ess a
o ems wi a se i ks Com u a io i ks a u - ime ca e e e si e i a a ge sys em wi ma y use s (As ma 1997 O e -com e e ess occu s w e e ea e is
ese e wi mo e i ks a e/s e ca com e e ( is ewai e 1997 a se i ks may occu ecause o o ysemy i e mu i e wo s a se e ces a ea e sea c a go i m o i co ec y u ge e simi a i y o e agme s is may ea o u sou
i ks ( is ewai e 1997 i e y e e I sys ems su o o s a ic a y amic
i ks
3 3 Automatic Link Generation. I a i io a y e me ia sys ems i ks a e c ea e ma ua y Ma y o e e is i g i ks i e Wo Wi e We a so a e ma ua y c ea e wo key a a ages a e a au o s ca o i e ca e u y- e i e s eci ic
e a io s i s a a use s o e i o ma io a e a co e i w ic o u e s a i o ma io owe e ese a a ages ca e i icu o ea i e as e si e o e i o ma io s ace g ows (Wi ki so 1999 Some o e o ems a e
• e si e o e co ec io may e sim y oo a ge o a ow o uma assig e e a io s i s
• e co ec io is su icie y y amic a uma mai e a ce cos s a e oo ig ( is ewai e 1997
• Use e e e ce a i e ac io a e u a e o e co si e e i e i ks a e c ea e ma ua y i a a ce
o au oma ica y ge e a e i ks e a io s i s e wee ieces o i o ma io s ou e co si e e S uc u a e a io s i s a sema ic e a io s i s cou e use w e ge e a i g i ks esea c wo k as ee o e i e e a io s i a a ysis a ea
(A a 199 a ie e Au oma ic i ks ca e s a ic o y amic S a ic au oma ic
i ks a e e-com u e i ks ase o simi a i ies e wee a ai s o e a e i o ma io A simi a i y es o is use o c assi y i k y es y amic i ks a e c ea e o e y ossi y aki g i o accou e use e e e ces o use i e ac io s
u y au oma ic i k ge e a io as o ems I a simi a i y es o is use
e e e s o e a e y u e e c ea io o i ks wi uge um e s o i ks o a om some o ec s a o a s o o e s (Wi ki so 1999 I sys ems su o o ma ua a au oma ica y ge e a e i ks 5
2.3.3.3 Embedded vs. External Links. a is (1995( y e me ia sys ems may
e c assi ie y ow ey s o e i k a a c o i o ma io a ow ey is ay i k ma ke s i k i o ma io i c u es i k I ame sou ce a es i a io a c o I (o
ame i k co e (suc as e es i a io i e s U A c o i o ma io i c u es a c o I ame ysica osi io (suc as e y e o se o e se ec e e i e sou ce ocume a co e (suc as e se ec e e o e am e i a use a s a
i k o some e i a M We age e i k ma ke is ig ig e as ue u e i e e e i k i o ma io is associa e wi e se ec io is e i e ue u e i e e is e se ec io e e a e ee a oac es o s o i g is i o ma io
• Embed the entire link and anchor information within node content at the link marker.
Ma y o e ea ie y e e sys ems ake is a oac e Wo Wi e We a so em e s i s i ks (as M ma k-u e a a age is a e ocume a i s i ks o m a se -co ai e o ec w ic may e mo e a e i e wi ou amagi g a y o e i ks e ocume co ai s e isa a ages o em e e i ks a a c o s i c u e
(1 Mo i g (o e e i g a ocume equi es c ecki g a e e e ces o is ocume wi i a o e ocume s
( I is o ossi e o u a e o i se ma k-u i ocume s ow e y a o e use o o a ea -o y me ia suc as C - OM
(3 I co o a i g e same i ks i i e e ocume s equi es o u ica e e a c o a i k i o ma io
• Embed tags to store anchor information in source and destination nodes but store the link information externally.
is a oac was io ee e y e Su i k Se ice ( ea 19 9 a is ake y ma y o e y e me ia sys ems suc as S 3 A i k a a ase o s i o ma io a ou w ic o es a e co ec e y e i ks u e a ica io is es o si e o mai ai i g e a c o i o ma io Wi a i k s uc u e e ce a y o e ca ui oo s w ic a iga e e i ks (suc as owse s as we as oo s o i e i y a g i g i ks 26
• Store both the link and anchor information externally.
Intermedia, Microcosm, Hyper-G and other application take this approach, which has a number of advantages over the other approaches:
(1) Links may be made into and out of read-only material, since the pointers are stored externally.
(2) Anchors are easier to use with non-text materials.
(3) Bi-directional or multidirectional links could be supported.
(4) Users may select in which of a number of alternative webs (link databases) to store a particular link.
(5) Third party applications may be used as link service enabled viewers. Because document content contains no proprietary anchor mark-up (as in the previous approaches), any generally enabled viewer should be able to display it.
(6) A local map (fish-eye view) can be readily computed and visualized using the link database.
A major disadvantage to separating the structure from the data occurs when an editor changes a file, causing links to point to the wrong positions within the node.
How a system stores link anchors affects the media and tasks it can support, as well as the services it can provide. JIT systems store link and anchor information externally, but may embed links in Web pages immediately before display.
2.3.3.4 Semantically Typed Links. A link type (Allan 1996) is the description of the relationship between the source and the destination of a link. It has long been accepted that typed links have the potential to support a wider range of automated and user tasks within a hypertext system. One of the common criticisms of the traditional
WWW is that the semantics of linking is typically highly localized. The types of links that are to be made available are typically tailored towards the specific application, considering the nature of the content, users tasks and so on. Authors have experienced difficulty in defining a manageable small set of link types that is also sufficiently rich to 27 capture link semantics, large sets of link types raise the issue of ambiguity. Systems that provide very few link types include KMS (Akscyn 1988) and HDM (Garzotto 1993).
Systems with a small number of types often allow the source anchor to provide additional information about the link. For example, KMS has only two link types, but allows an anchor to express the semantics of the link to which it is attached. KMS also allows information about a link to be expressed in the mouse cursor that appears when the mouse is moved over an anchor. Other systems provide more link types, such as gIBIS
(Conklin 1987) and TEXTNET (Trigg 1986). Whilst many of these link types are highly application specific, there have been suggestions that it might be possible to define a standard application independent core set of link types. A related issue is whether the set of link types should be defined by the development tool, by the authors of application built using that tool, or by the users themselves.
Allan (1996) presents a technique for automatically linking documents of related subject matter. Moreover, an extension of the technique, inspired by document visualization, allows automatic classification of the links into several types from a pre- specified taxonomy of links. Links can be divided into classes in several ways. Trigg
(1987) provides the major divisions of internal "substance" links and external
"commentary" links. Each of those is then broken down into subclasses, and so on. In all, Trigg lists a set of 80 classes of link types. Parunak develops his own hierarchy of hypertext link types, including 27 types in three broad categories: revision, association and aggregation. 28
In Allan (1996), they present an amalgam of known link types and divide them into three major categories based upon whether or not their identification can be achieved automatically. The three categories are n l, p tt rn t h n nd t t . The approach presented for automatically typing a link between two documents is based upon straightforward statistical analysis of relationships (also statistical) between the sub-parts of the documents. However, statistical information retrieval techniques are imperfect and unable to handle word distinctions in meaning: the same subtleties of language that confuse a retrieval system will cause problems with the typing methods.
JIT systems can provide semantically typed links for users. JIT systems should allow users to manually create link types and also should be able to supply link types automatically based on the underlying relationships between documents and elements.
2.3.3.5 Link Service. A link service system stores links as independent objects in an external linkbase. A link service system has the ability to control the links in many aspects (Carr 1999):
• n n l n: in which way does the link embed with the requested documents.
• n pr nt t n: how are links marked in the display of a node? For example, plain links are usually marked as blue underlined text in HTML documents or black outlined buttons in PDF. Users could specify how the link presentation format would be.
• n pr r t z t n: how important the link is? It could be ranked by the user or the system based on some criteria. Link ranking is an important topic in hypermedia research.
• n nt : what kind of semantic information is associated with the link? 2
The Microcosm system provides open hypermedia services for early WWW browsers. It allows WWW documents to contain generic and computed links that are more flexible than the native HTML links. However, it led to the situation where the browser offered a porthole into the distributed data of the WWW, but the hypertext links were maintained locally on the PC. To make use of the links requires the user to obtain both the Microcosm linking software and the link databases themselves (Carr 1998[1]).
The Distributed Link Service (DLS) (Carr 1995) was developed to work in conjunction with existing WWW resources to support an additional underlying link service. It is composed of the server facilities that were accessed via the WWW and the client interface that worked in conjunction with a WWW browser. The server facilities are implemented as CGI scripts, and are accessed using a standard WWW server. The main scripts are those that allow the creation, following and editing of links which are stored in link databases. The client interface formulates requests for linking functions and dispatches these requests to a DLS link server for processing.
Earlier link service systems include Proxhy (Kacmar 1991), Multicard (Rizk
1992), Sun's Link Service (Pearl 1989), and Chimera (Anderson 1994). Each of these systems expects client information systems to support anchor creation and selection by embedding hypermedia calls and handling minimal hypermedia functionality. They also provide multiple levels of hypermedia navigation and annotation support, based on the degree of hypermedia compliance the client non-hypermedia information system provides, as well as a limited set of support for client systems that are not hypermedia compatible at all. 0
I e a e 199 s i k se ice sys ems ase o o e y e me ia a a a i e
y e me ia we e e e o e CO SE (Ca 1 is a We - ase o e y e me ia i k se ice a ca o e a a ge o i e e i k- o i i g aci i ies i a sca a e a o - i usi e as io e co ce ua o e y e me ia se ices a e i eg a e o o m a co ce ua y e me ia sys em o e a e ocume s o e i ke ia me a a a esc i i g
ei co e s a e ce o im o e e co sis e cy a ea o i ki g o WWW
ocume s a e ie a ime (as ea e s owse e ocume s a au o i g ime (as au o s c ea e e ocume s AA S ( e so a Age i o ma io Acquisi io a
e i e y Sys em ( ai ey is a a a i e y e me ia i k se ice sys em usi g age s e e a e ee ki s o age s i e sys em w ic a e e e so a use age
e k ow e ge ase age a e i k ase age e e so a use age u s a e c ie si e acki g e use ac i i y a accumu a i g i o ma io a ou use i e es s
is i o ma io is s o e i a use mo e a e se o e se e -si e k ow e ge ase age e k ow e ge ase age ac s as a ce a e osi o y o a a accumu a e y
e so a age s a a es que ies a ou e use mo e a a om c ie s e i k ase age mai ai s a i k ase a a ows e use o a o emo e i ks
A I sys em is a i k se ice a s o es i k i o ma io i a e e a a a ase a o i es sema ic i o ma io o i ks
2. . .6 i k I eg i y. y e e i ks a e co ec io s e wee ocume s o
a s o ocume s Ge e a y e e s o i ks a e e ese e y some ki o a
e e e ce o a ocume o a o a ocume W e ocume s a e mo e o c a ge
ese e e e ces may cease o eso e o e co ec aces
W e e o ec a o e e o a i k is o ese o is o e o ec a was i e e y e i k au o e e i k is sai o e oke (I g am 199
i k i eg i y is a im o a o ic Mos o e ea ie y e e sys em
e e o e s assume a i was a o e ask o e y e e sys em o e su e a i k i eg i y was mai ai e a is assum io was em o ie i e e e Mo e ( a as
199 owe e wi e a e o is i u e y e e s i ecame i icu o e sys em o mai ai is i eg i y e Wo Wi e We su e s a icu a y om is
o em as e e i e i k o ma y is em e e (as a U i e sou ce ocume I wou e im ossi e o e emo e si e o i o m a ocume s oi i g o i o e c a ges si ce e e a e o ackwa oi e s; i wou e ecessa y o i e oga e e e y
M ocume o e e y mac i e i e wo o i ou w e e i oi e o is se e W e e i k is oke o e WWW i e mi a es i e i amous e o
( a is 1999 E o s a e ee ma e o e su e i k i eg i y o e WWW suc as e
U sys em (w ic wi e iscusse i C a e
e co e e e e ce o em is a o e as ec o e i k i eg i y o em I occu s w e a ocume is e i e u e e e e ces i o e ocume a e o u a e
is o em oes o a e i WWW M i ks as e a c o s a e em e e i e
e a a e e e o e mo e as e e is e i e owe e mos mo e y e e sys ems o use some so o oi e o e e e ce i k a c o osi io s i ocume s a as e We commu i y s a s o a o e ew oi e ( oi e s a a s e same o em wi eme ge e e 3
i k i eg i y is a im o a issue i I sys ems ecause y amica y- ge e a e i ua ocume s cou a y eque y " a g i g i k" o ems a e mo e eque y a wi s a ic ocume s
3 3 7 Links in JHE System. A a c o i e o ose E sys em is a
se ec io (w ic cou e a o e ocume o e w o e ocume i a y amica y- ge e a e i ua ocume A i k i e E sys em is e co ec io e wee wo
se ec io s o mu i e se ec io s i o e o mo e ocume s E su o s s a ic a
y amic i ks S a ic i ks i E a e ma ua i ks c ea e y use s w ic is simi a o
a i io a sys ems W a E o e s ew a e r l t n a r d nt f t n ocessi g w e e ious y- is aye ocume s a e e is aye (see C a e 3 o e ai s
y amic i ks i E sys em a e com u e ase o e i e e e a io s i s e wee e eme s me a a a s uc u e ocume s uc u e e a io s i s amo g a ica io
s eci ic comma s a a ame e s use g ou e a io s i s e c ese e a io s i s cou e a a y e e o e e y e me ia i e ace is esig e o a e ime a a c o is
se ec e a E e y amica y e e mi es e i ks E ca su o o e y es y a a y i g e y amica y-ge e a e i ua ocume y es oug c assi ica io a
oug ca ego i i g e comma s a a ame e s CHAPTER 3
US ΙΝ ΤΙΜΕ Y E ME IA AMEWO K
This chapter describes the just-in-time hypermedia framework. It first gives differences between dynamically - generated virtual documents and static documents in Section 3.1.
These differences exist in many aspects, including status, storage, reference, generation, regeneration, template, metadata, editable, versioning and anchoring. Table 3.1 shows details. Section 3.2 compares dynamic hypermedia functionality with static hypermedia functionality. The major differences are that just-in-time hypermedia requires dynamic regeneration of virtual documents, re-location and re-identification of anchors in virtual documents. Section 3.3 discusses dynamic regeneration in terms of requirements, revalidation criteria, regeneration procedure and parameters required for regeneration.
Section 3.4 discusses re-location and re-identification of virtual elements, in terms of requirements, procedure, re-identification criteria and parameters required. Static edited documents could have similar problems but could be handled in simpler ways than with virtual documents. Section 3.5 describes the just-in-time hypermedia framework. Section
3.5.1 lists requirements of a just-in-time hypermedia system. Section 3.5.2 describes the conceptual just-in-time hypermedia architecture. Logical components of the JIT architecture are depicted in Figure 3.1 and described in Section 3.5.2.
3.1 Dynamically-Generated Virtual Documents vs. Static Documents
The differences between dynamically-generated virtual documents and static documents are shown in Table 3.1.
33 4
a e . y amica y-ge e a e s S a ic ocume s
Dynamically-Generated Virtual Document Static Document
S a us y amic a i ua oes o e is i a a ce o y e is s S a ic a ea s o e e sis e y i some w e e use isi s e i ua ocume ysica oca io wi a s eci ic i e ame S o age O y s eci ica io s o i ks a o e i o ma io a ou e e e i e co e o e ocume is s o e ocume a e s o e ; equi es muc ess oom e e e ce Cou e e e e ce y a u ique ocume i e i ie o some e e e ce y i e ame oca io o a s eci ica io s a ou e ocume u ique ocume i e i ie Ge e a io (1 y amica y ge e a e y que y sea c sys em (1 O e c ea e ma ua y comma s o use ac io s e e i g o a ame e s s eci ie ( O ce c ea e e a e ime i e si e a y use e ocume co ai s esu s om e a a ase o co e a e co sis e com u a io mo u e; o y amic i o ma io suc as a e o ime ( e c ea io a e a ime i e si e a co e cou c a ge wi eac ge e a io ege e a io ege e a io is equi e e e y ime e use e isi s e o ege e a io is equi e ocume em a e Usua y some ki o ocume em a es com osi io Ca o ow a e e i e o ma o e ee- a go i ms sc i s o ske e o s aci i a e e ocume s o m com osi io o ga i a io a com o e s u i g y amic ege e a io Me a a a Usua y i is o i icu o a a y e e me a a a ecause e Me a a a may e o i e I o e i ocume is e esu o que y sea c o ca cu a io use u o e wi e i icu o i e me a a a s ou e a ai a e o e am e e que y esu s om a a ase a e some e i i e me a a a e use ac io s (comma s + a ame e s a e k ow e y amic i o ma io ( a e ime as c ea mea i gs a e ca cu a io as e i i e me a a a E i a e U ess e i ua ocume ca e sa e as a s a ic ocume Usua y e i a e e a e ime a i e si e e a i i y o e i i is i e e a o e u oses o y amic i o ma io cou e use o i ica e y e me ia u c io a i y i ua ocume s a e o e i a e w e e e i e as ee e i e a o y ca e ge e a e y e u e yi g a ica io e sio i g I o e o e sio e ocume Usua y e o me y a ocume (1 is o y i o ma io a ou e o e sio s ou e ke e sio i g sys em Usua y e o igi a a some imes a mi ima co y o e o e sio is equi e e sio o e ocume is ke e o ( a e a ime i o ma io is o e y use u o i ica e eac e sio e sys em oes a i e a is is a o e e sio com a iso a kee s e i e i e e ces (3 e i e si e cou e use o i ica e a i is a ew (" e as" W e is ayi g e ew e sio e sio o e e e a wo e sio s a e ea e as e same e i e i e e ce is a e o e o e sio ( u e iscussio a e o ec ea e e ew e sio a e ime a ( y e- y- y e com a iso is o ossi e ecause o y a i e si e i o ma io is e y use u o mi ima co y o e ocume is ke ( is a so e e s o e e sio i g u oses wo e sio s a e ea e as e same as iscusse a e
A c o i g o eco e a c o i o ma io i e a ocume As o g as e ocume as o ee e i e e eme s i a a essi g is equi e ossi y usi g e same me o s as e e is o ee o e oca e a e-i e i y ocume wi s a ic ocume s E e y ime a use e isi s e ocume e a c o s owe e i a c o s a e s o e e eme e oca io a e-i e i ica io a e equi e ( e ai s i a e e a ase ey ec ica y ee o wi e iscusse a e e e oca e u is is s aig o wa
a e 3 1 gi es e o owi g co c usio
(1 y amica y-ge e a e ocume s ca e c ea e i ma y e i e ways 35
( I is mo e i icu o e e e ce a e sio i ua ocume s o e e e ce a i ua ocume a u ique ocume i e i ie is equi e a a eso u io sc eme is ee e e " us -i - ime" ( I y e me ia sys em s ou e a e o ge e a e u ique i e i ie s a mai ai em E e y ime a i ua ocume is e e e ce e I y e me ia sys em s ou eso e is I o e s eci ica io s o e i ua ocume o ege e a e
(3 Mai ai i g y e me ia wi i y amica y-ge e a e i ua ocume s ea s o equi eme s a a e i e e om s a ic ocume s i c u i g y amic ege e a io e oca io a e-i e i ica io w ic wi e iscusse a e
3.2 Dynamic vs. Static Hypermedia Functionality
W e e a a y ica a ica io is su eme e wi y e me ia u c io a i y o is
" us -i - ime" e i o me i is ca e y amic y e me ia u c io a i y y e me ia
u c io a i y i c u es s uc u i g (global and local overviews; trails and guided tours; node, link and anchor typing), a iga io a (structure-based query, history-based navigation and bi-directional linking), a a o a io (user-declared links, comments and bookmarks) u c io a i y ( ie e 1997 e y amic u c io a i ies wou a e o o e a e o e i ua ocume s
e y amic y e me ia c ea e i is " us -i - ime" e i o me causes
o ems o ou i s a ic e i o me s Α com a iso o e y amic y e me ia
u c io a i y wi e y e me ia ge e a e i s a ic y e me ia sys em ig ig s a
(1 e es i a io s o use - ec a e i ks comme s a ookma ks o es o e is o y is a o e iews s o s a o g ai s a gui e ou s a a e y amic a i ua W e e use a e ses o em e I y e me ia sys em s ou ege e a e e es i a io s w ic o ma y mea s e-e ecu i g e comma s associa e wi ese es i a io o es y usi g some ege e a io u es
( O ce a o e is ege e a e e I y e me ia sys em mus e oca e e a c o s a use s e ious y a ace wi i is o e a s ou e-i e i y a y e eme s a e a c o s co e as e same o es as e o e 36
(3 W e a a y ica a ica io s ge e a e ew que y esu s e I y e me ia sys em s ou e a e o e oca e a e-i e i y e a c o s o k ow e eme s a ea i g i o e que y esu s o e am e a use a s a comme o a e eme wi g o a access e missio s so a o e use s ca see is comme e e yw e e a e same e eme a ea s I is si ua io e e y que y esu co ai i g a same e eme s ou a e a a c o associa e wi a g o a comme
( O e iews a s uc u e- ase sea c (as we as co e - ase sea c o e s eci ica io i ks mus o e a e o e a y e e we a oes o e is I s ea ese u c io a i ies mus i e e o e ia o o e a i k e is e ce a o e co e ase o a y a ai a e s eci ica io s a ou e o es a i ks is o ica eco is o e oug o use s wi o wa o see o y e o es a a e e ious y ee ge e a e I s ea ey wa o e o e w a ossi y cou e ge e a e y ei a ge a ica io
e mai i e e ces e wee " us -i - ime" y e me ia a s a ic y e me ia is
a " us -i - ime" y e me ia o e a es o i ua ocume s a i ua e eme s wi i
i ua ocume s equi es y amic ege e a io e- oca io a e-i e i ica io ese
ee im o a issues wi e iscusse i mo e e ai
3.3 Dynamic Regeneration
Some We sys ems ege e a e a a ysis sc ee s y s o i g a e e a a ame e s i e
i ua ocume s U u ma y We - ase a o -We ase egacy sys ems a e
o suc mec a ism O e We sys ems o o a ow U s wi e ai e a ame e s o secu i y o o e easo s W e e use ookma ks a e u s o i s U suc sys ems may e u e use o e ome age o e i i ia i u age e I y e me ia sys em mus o i e au oma ic ege e a io wi ou aski g e use o ee e
a ame e s y amic ege e a io as e o owi g equi eme s 37
(1 A u ique a e sis e i e i ie o eac i ua ocume s ou e ge e a e a eco e E e y ime e use a e ses a ookma k o o e i k e o s e s ou e u o e same i ua ocume o e wise ese ookma ks o i ks wi o o ge e a i e I y e me ia sys em cou kee a is o a ica io comma s a a ame e s a i s ge e a e e i ua ocume i a a a ase keye o e i ua ocume i e i ie I a so cou s o e a ocume em a e i a ai a e o e uci e W e e use i s ge e a es e ocume e I y e me ia sys em s ou e e mi e o c ea e a u ique I o is ocume W e e use ies o e isi i e sys em s ou use e same I e ie e e co es o i g comma s a a ame e s om i s a a ase a e-e ecu e e comma s o y amica y ege e a e e i ua ocume
( W e e e e I y e me ia sys em ecei es a ocume o is ay e e s ou e some way o k ow w e e e sys em as is aye i e o e o y amica y-ge e a e ocume s e co e a ocume s uc u e cou e c a ge wi ou a y o ice; e e s ou e some c i e ia o eci e i is is e same ocume as e o e o owi g a e some "same ess" c i e ia o e e mi i g is is e om e y igi o e y e i e
• e i e co e a s uc u e s ou e e ac y e same ( e y igi
• e i e s s uc u e emai s e same u e co e cou e i e e o e am e e eme a ues suc as e cu e a e o cu e s ock ice may i e om e as ime e ocume was ge e a e u ese e eme s wi e i e same e a i e oca io wi i e ocume as e o e
• Some c i ica sec io s o e ocume s ou o c a ge; o e sec io s may
• As o g as e que y is e same o e a ge e a e i e sys em ea s i as e same ocume ( e y e i e
W ic c i e io e a ica io o e use uses e e s o is o e equi eme s I c a e 1 s e am e w e e a a ys i e que y a u some comme s o a sc ee s e e i e es e i a a icu a que y o a a icu a ay so s e wa s e i e ica a a ysis esu s I e ime w e s e e isi s is comme a e ew y-ge e a e ocume is o same e I y e me ia sys em s ou gi e a "i a i ookma k" o "s a e ocume " wa i g a a ow e use o emo e e comme o kee i O e o e a some imes a comme is a i o a y co e ge e a e y e same que y 8
(3 A s a ic ocume a as ee e i e a so as e e-i e i ica io o em Sim e ways e is owe e o i ica e a is ocume as ee e i e I a s a ic ocume is e i e o e am e e e i i g imes am c a ges W i e i a y amica y-ge e a e i ua ocume e e y ime i is ge e a e e a e a ime a ies I is si ua io e e oug e i e si e oes o c a ge e I y e me ia sys em as o e-i e i y w e e is ocume is e same o e as e o e
. . ege e a io oce u e
e ege e a io oce u e as e o owi g s e s
(1 W e a use makes a i k o a i ua ocume (a ma ua i k a ookma k a i k as a s e wi i a gui e ou e c e I y e me ia sys em eco s e i k i o ma io
( W e e use a e ses a i k o e isi e i ua ocume e I y e me ia sys em ooks o e i k i o ma io om e i k i o ma io i i s e ecessa y comma i o ma io (i c u i g a y a ame e i o ma io o e-e ecu e e comma s
(3 e I y e me ia sys em se s e comma i o ma io o e u e yi g a a y ica a ica io
( e u e yi g a ica io e ecu es e comma s a ge e a es a i ua ocume
(5 e I y e me ia sys em ecei es e i ua ocume a e a i a es i e a i a io o a i ua ocume e e s o w ic same ess c i e ia e I y e me ia sys em o e use c ooses w ic a e ee iscusse a o e
( I e ege e a e i ua ocume is e a i a e as e same as a ge e a e e ious y e e ege e a io is success u o e wise e I y e me ia sys em gi es a "s a e ocume " wa i g o e use
e comma s w ic e I y e me ia sys em se s o e a ica io o e wi e e same o es a e use e ecu e w e ge e a i g e ocume e i s ime
A a ime w e e use o e am e issue a se ies o og essi e que ies i u i g a se o a ame e s o eac a ookma ke e i a esu e I y e me ia sys em
recorded the steps and parameters. When regenerating, the system repeats these steps, filling in the parameters that the user originally entered. This occurs in the background, so the user only sees the resulting document (and is not required to reenter any input parameters). For example, suppose the user invoked a wizard that presented a series of dialog screens to gather input values before generating a document. The JIT hypermedia system could invoke the wizard in the background. Instead of displaying each dialog for the user to reenter the input values, the system fills each dialog in with the stored values originally entered and submits it. The user just sees the resulting document generated by the wizard, which (presumably) is the same one as she originally saw. (The JIT hypermedia system will have to use the sameness rules discussed earlier to validate this.)
Alternatively, when integrating an application with the JIT hypermedia engine
(see Chapter 5), the integrator could specify "regeneration rules" for each class of virtual documents. The regeneration rule could provide a shortcut set of commands and parameters that can generate the virtual document more directly. If a regeneration rule is available, the JIT hypermedia system could pass all required parameters. For the wizard example, a regeneration rule might bypass the wizard and issue a single command to generate the document directly, using the parameters that had been stored the first time.
3.3.2 a ame e s o ege e a i g i ua ocume s
In order to regenerate a virtual document, the JIT hypermedia system should record the following information: dynamic link information, virtual document information, document generation information and document revalidation information. They are described in detail as follows: 40
Dynamic Link Information:
y amic i ks a e ose ea i g o a i ua ocume s eci ica io ese i c u e y e me ia se ices o u c io a i ies suc as use - ec a e i ks ookma ks a oca io s wi i a gui e ou
n d nt f r: is s ou e u ique a e sis e
tl : i k ame o a e
r pt n: ie esc i io o is i k
rt l d nt d nt f r: w ic ocume is i k ea s o
U r nf r t n: w o c ea e is i k
t nd t : e a e a ime is i k is c ea e
Virtual Document Information:
rt l d nt d nt f r: is s ou e u ique a e sis e
A b l t : Some g ou s o use s a e a owe o ac i a e e comma s a c ea e e ocume ; o e g ou s o o a e e ig o e am e a sys em a mi is a o s ou a e access o a ki s o i o ma io a ma age ca iew e sa es eco s o is em oyees u as o ig s o see o e g ou s eco s; a sa es e so may a e e y imi e i o ma io accessi i i y A ese access ig s a e ea -o y; ecause ese esu s a e om a ca cu a io o que y ey s ou o e c a ge a e e is o way o w i e ese ocume s ack ecause ey a e ge e a e y amica y a o o ge e is w e e wi ow is c ose (A e e sio o e I y e me ia sys em wou e a owi g use s o sa e s a ic e sio s o i ua ocume s a cou e e i e o e ie i g e is i g s a ic ocume s i w ic case access e missio s mus e e e e o em
r n: i e i e co e o s uc u e c a ges e oug ma k is as a ew e sio
tl : e ame o is i ua ocume s o e as a is ay a e o i s i k
r pt n: ie esc i io o i s s eci ica io (e g e que y o o e comma s a ge e a e i
S z : i e si e
Str t r : e eme is a e oca io s o e e eme s 41
M t d t : e me a a a o e i ua ocume a i ua e eme s wi i i
Revalidation Information:
rt l d nt d nt f r: is is e same i e i ie as i i ua ocume i o ma io a o e
Cr t r : w ic c i e ia e I y e me ia sys em o e use c ooses o i e i y a e ew y- ege e a e i ua ocume is same as e i ua ocume isi e e ious y
C nt nt: some c i ica sec io s o e i e o some e eme a ues mig ee o e ke o e a i a i g e ocume W a ki o co e o kee e e s o w ic c i e ia e I y e me ia sys em o e use c ooses
Generation Information:
rt l d nt d nt f r: is is e same i e i ie as i i ua ocume i o ma io a o e
Appl t n d nt f r: w ic a ica io ge e a es is i ua ocume
C nd: w ic comma s a e use o ge e a e is i ua ocume
r t r : w ic a ame e s a e use o ge e a e is i ua ocume
Sh rt t: w ic e aceme comma s ca ge e a e e i ua ocume mo e i ec y
pl t : w ic ocume em a e is use o aci i a e e ge e a io i a y
3.4 Relocation and Re-identification
e-i e i ica io a e- oca i g o es a a c o s a e e o owi g com ica io s
(1 e I y e me ia sys em mus ecog i e e e-ge e a e o e is e same o e as i o e e e ious y is issue as ee iscusse i e ai a o e
( A e a i ua ocume is ege e a e e I y e me ia sys em s ou e a e o i ose a c o s a we e ma ke i is ocume e ious y is is ca e e oca io
(3 e I y e me ia sys em mus ecog i e a some co e wi i a ew y ge e a e (o ege e a e o e is e same e eme as o e ma ke as a a c o e ious y
( W e e use c ea es a i k s e ee s o eci e w e e i s ou a ea e e y ime e e eme a ea s i a y o e e e y ime i a ea s i si e a a icu a o e o y (e g o y o a a icu a que y o o y o a a icu a i s a ce wi i a a icu a o e o e am e e use may ace a comme o a e so s ame u o y mea i o o e a icu a a ag a i si e a ocume i w ic e ame is me io e se e a imes is is ca e relocation granularity.
(5) As wi a s a ic y e me ia sys em e I y e me ia sys em mus e e mi e w ic a c o s (a o w ic i ks ey ea a e a ai a e o e e-i e i ie a e- oca e e eme s i a ( e -ge e a e o e e u ique i e i ie is c ucia e e
3.4.1 Procedure for Relocation and Re-identification
e e oca io a e-i e i ica io oce u e as e o owi g s e s
(1 e i s ime a use se ec s a ma ks a a c o o e sc ee e I y e me ia sys em eco s e a c o i o ma io i a e e a a c o a a ase
( A e a i ua ocume is ege e a e a e-i e i ie as e same o e e I y e me ia sys em ooks o e a c o i o ma io o is ocume i e e e a a c o a a ase
(3 o eac a c o i si e is ocume e I y e me ia sys em i s e e ac osi io i si e e ocume e y e o se o a e eme cou c a ge i e ocume s co e c a ges e wee ge e a io s o e am e a sim e c a ge i e cu e a e cou s i y e osi io s A e i e a sma i e a ocume -a essi g sc eme suc as A s ou e use o e- oca io u oses
( o e e- oca e a c o e I y e me ia sys em s ou e-i e i y a e ew y-ge e a e e eme is same as a se ec e as a a c o o e i e c i e ia i wou a ow a c o a ue o c a ge o igi c i e ia; i oes o a ow a c o a ue o c a ge
(5 A e e a c o e i ua e eme s a e e oca e a e-i e i ie success u y e I y e me ia sys em ooks o ose y e me ia u c io a i ies associa e wi ese e eme s i e a a ase a associa es em wi a c o s 3
3 Parameters for Relocation and Re-identification o e oca io a e-i e i ica io u oses a c o i o ma io i ua e eme i o ma io a e-i e i ica io c i e io a e ee e
Anchor Information:
An h r d nt f r: is s ou e u ique a e sis e
tl : a c o ame o i e
r pt n: ie esc i io o is a c o
Gr n l r t : is a c o cou a ea a a a icu a oca io i a a icu a ocume o e same e eme a yw e e i a a icu a ocume o cou a ea i a y ocume a as e same e eme
S l t n nt nt: some co e o e e eme o some co e a ou is e eme
t n: i e a a essi g i e ocume
U r nf r t n: w o c ea e is a c o
t nd t : w e is a c o was c ea e
Virtual Element Information:
El nt d nt f r: is s ou e u ique a e sis e
M t d t : w ic me a a a is e eme uses a e I y e me ia sys em s ou use o e a i a e e e eme
r n: i e a ue o a e eme c a ges is cou ossi y e a o e e sio
S z : si e o e e eme
A b l t : w o as access ig s o is e eme
Re-identification Criterion Information:
El nt d nt f r: is s ou e u ique a e sis e 44
Cr t r n: w ic c i e io e I y e me ia sys em o e use uses o e-i e i y e e eme
C nt nt: some a s o e e eme s a ue o me a a a w ic a e use o e- i e i ica io u oses
3 5 JIT Hypermedia Framework
I a se e ce a " us -i - ime" y e me ia sys em is a y e me ia sys em a ca su eme y e me ia u c io a i y o y amica y-ge e a e i ua ocume s e
I y e me ia amewo k is ese e y iscussi g e equi eme s a e ogica com o e s o e I sys em
3.5.1 Requirements
As iscusse i Sec io s 3 1 o 3 e ma o equi eme s a i e e ces e wee e
" us -i - ime" y e me ia a a i io a y e me ia sys ems a e a I y e me ia
equi es r n r t n, r l t n a r d nt f t n. esi es is o e equi eme s i c u e i ua ocume su o ; ocume ge e a io ; u ique i e i ie s o i ua
ocume s a e eme s; i e a ocume a essi g mec a isms o e eme s; a ica io s eci ic me a a a su o ; y e me ia u c io a i y; i eg a io wi iewe s a i eg a io wi i o ma io sys ems ese equi eme s a e iscusse i e ai as
o ows
• i ua ocume su o
a i io a y e me ia sys ems ea wi s a ic ocume s w ic a e e sis e i e ames a oca io s A I sys em s ou e a e o e e e ce a i ua ocume eco i s i o ma io a e a e y e me ia se ices o ese i ua ocume s A so i s ou e a e y e me ia se ices o s a ic ocume s 4
• ocume ge e a io
A I sys em s ou e a e o ge e a e a ocume w e a use asks o i ocume ge e a io may e a e y a i e e e u e yi g i o ma io sys em owe e e I sys em s ou a e e a i i y o co o e ge e a io ocess a sema ic i o ma io a is ay e ocume s o iewe s
• ocume ege e a io
W e a use a e ses o a i k a c o o ookma k a was u o a i ua ocume e I sys em s ou ege e a e e ocume a e e a i a e e ege e a e ocume
• y e me ia u c io a i y su o
y e me ia u c io a i y s ou wo k o e y amica y ge e a e i ua ocume s wi a simi a e ec as o s a ic ocume s
• e- oca io a e-i e i ica io
W e a use a e ses a i k o comme a was u o a i ua e eme i a i ua ocume e I sys em s ou e a e o i e oca io o e a c o o is e eme i e ocume is is ca e e oca io e I sys em a so s ou e a e o e-i e i y e a c o e i ua e eme s i e i ua ocume
• U ique e sis e i e i ie s o i ua ocume s a i ua e eme s
e e e ce o i ua ocume s a i ua e eme s equi es u ique a e sis e i e i ie s ac oss e y e me ia sys em
• I e a ocume a essi g mec a isms
e- oca io a e-i e i ica io o i ua e eme s equi e e i e a e icie i e a ocume a essi g mec a isms
• A ica io s eci ic me a a a
e me a a a o e a ica io s s ou e a a y e a su o e o e e e a i is use w e e I sys em ege e a es a e a i a es e i ua ocume s a e eme s 46
• I eg a io wi iewe s
A y e me ia sys em cou su o mu i e iewe s (e g We owse s a i e aces o o -We a ica io s ecause a ica io -ge e a e ocume s cou e is aye y i e e iewe s is equi es i eg a io wi iewe s I eg a io wi iewe mea s e I sys em as a i e ace (mi ewa e e wee eac iewe w ic cou a s o m e I a a o ma s o a a o ma s a i e e iewe s cou u e s a o is ay
• I eg a io wi i o ma io sys ems
o su eme y e me ia u c io a i y o e u e yi g i e e e i o ma io sys ems i eg a io wi i o ma io sys ems is equi e i e e a ica io s gi e ou i e e sou ce ocume s i i e e o ma s Eac equi es a i e ace o mi ewa e o a s o m i s sou ce ocume s i o e u i e sa ocume s a e I sys em ca u e s a a ocess
. .2 ogica Com o e s
A co ce ua I S a c i ec u e is o ose i igu e 3 1 A ie esc i io o e co ce ua a c i ec u e is as o ows
iewe W a e : i eg a e wi iewe s I is com ose o e Se ec io Ma age ; e ocume ese a io Ma age a e Commu ica io Ma age
e S l t n M n r ge s e se ec io s (co e oca io om e sc ee
e nt r nt t n M n r a es e ayou o e i e a i ua ocume s a a s a es e i ua ocume s o e a a o ma a e iewe ca ecog i e e C n t n M n r ma ages e commu ica io e wee e iewe a e y e me ia e gi e
A ica io W a e : ma ages e commu ica io e wee e a ica io a e y e me ia e gi e I asses e a ica io ou u s o i e i y a y o e ia e eme s w ic E may wis o i e i y as i k a c o s I e a s a es e a ica io s eci ic a a o ma s o a y i e a ocume a a o ma a e y e me ia e gi e equi es
y e me ia E gi e: y e me ia E gi e is com ose o e p r d G t , e n r t n En n , e p r d S rv M d l nd e rt l nt M n r. 47
e p r d G t ea s wi e commu ica io e wee iewe w a e a e y e me ia e gi e a e commu ica io e wee e a ica io w a e a e y e me ia e gi e
e n r t n En n ea s wi i ua ocume ge e a io a e a i a io
e p r d S rv M d l su eme s i ua ocume s wi y e me ia u c io a i y
e rt l nt M n r ma ages u ique e sis e i e i ie s a o e e a e i o ma io o i ua ocume s a i ua e eme s I a so oes e oca io a e- i e i ica io o e ege e a e i ua ocume s a i ua e eme s
Figure 3.1 Α co ce ua I y e me ia a c i ec u e CHAPTER 4
RELATED RESEARCH
This chapter gives a fully detailed literature review on related research works. JIT hypermedia systems are related in following research areas: virtual documents, document structure, adaptive hypermedia, unique identifiers, and object identification and addressing mechanisms. Section 4.1 introduces concepts and lists a number of research issues on virtual documents. Existing research on virtual documents is reviewed in
Section 4.1. Section 4.2 describes three types of document structure, markup languages for documents, document structure standards and document templates. Section 4.3 discusses adaptive hypermedia and reviews several existing adaptive hypermedia systems and research trends. Section 4.4 describes unique identifiers in detail. Unique identifiers are crucial to JIT systems in order to reference virtual documents, regenerate virtual documents, and re-locate and re-identified virtual elements. Some concepts and design requirements on identifiers are given in Section 4.4.1. Section 4.4.2 gives an overview on
URI/URL/URN. The Uniform Resource Identifier (URI) is the most widely used identifier scheme on the Web. URLs (Uniform Resource Locator) and URNs (Uniform
Resource Namespace) are subsets in URIs. The URL syntax is described and some examples are given in Section 4.4.2.2. Because URLs are not persistent, the PURL
(persistent URL) and the URN standards are proposed to solve this problem. Section
4.4.3 describes the Digital Object Identifier (DOI), which is an important system for the publishing industry. Section 4.4.5 compares existing identifier systems and describes the identifiers in JIT systems. To re-locate anchors in documents, a flexible and efficient
48 49 i e a ocume a essi g mec a ism is equi e Sec io 5 esc i es y es o a c o s i e e ways o e ess oca io s i si e a ocume a se e a e is i g sys ems o s a a s s eci yi g oca io s Sec io 5 1 gi es o e iew o a essi g mec a isms Sec io 5 esc i es e y ime s a a w ic as e y e i e a com e ways o s eci y oca io s i si e SGM ocume s Sec io 5 3 esc i es a essi g me o s i Mic ocosm e O e y e me ia o oco (O a e O e
y e me ia I e c a ge o ma (O I Sec io 5 esc i es e a / oi e
a guages w ic a e e y use u o e ess oca io s o M ocume s Some e am es a e gi e o e ai e a guages i e ai Sec io 5 5 iscusses o ec i e i ica io a a essi g mec a isms use i I sys ems
4.1 Virtual Documents A e ec o ic ocume co sis s o o e co e a e i ks associa e wi a
ocume Suc ocume s may e s a ic a e sis e o ey may e ge e a e
y amica y a e i ua A i ua ocume is a ocume o w ic o e sis e s a e e is s a o w ic some o a o eac i s a ce is ge e a e a u ime (Wa e s
1999
A um e o i e es i g esea c issues mus e eso e su ou i g ese
i ua ocume s o e We ese issues i c u e e e e ce ge e a io sea c
e isi i g e sio i g au e ica io a a o a io (Wa e s 1999
Reference: ow o au o s kee ack o i ua ocume s o e sio s o i ua ocume s? I is esea c a u ique I is ge e a e a mai ai e o eac i ua ocume o eac e sio o e i ua ocume e I y e me ia sys em mai ai s i o ma io a ou e i ua ocume s W e e i ua ocume is ee e e I y e me ia sys em uses e u ique I o ook o e i ua ocume i o ma io a 50 ge s e comma s a a ame e s o ec ea e e i ua ocume i ege e a io is ecessa y
Generation: A w a oi i ime is a i ua ocume e i e ? A i ua ocume ca e e i e y a au o oug e use o em a es a i ks o i ca e e i e as e esu o a sea c o a ica io a we a C am es ( a we 1999 e i e i ua ocume s as a o -o ga i e co ec io o I o ma io icks (ΙΒ associa e wi me o s a owi g e ge e a io o a i is e seque ce Me o s a mus ake i o accou i c u e e e i e i ks e wee I s i a y a y a ame e s su ie use ac io s a a s eci ic ge e a io s a egy I is esea c i ua ocume s o ma y a e c ea e y a a ica io as e esu o a use sea c o que y
Revisiting: Use s a e a e ec a io a ocume s ou o ce wi e a ai a e o a su seque sea c e o io o a ookma k oes o a y o i ua ocume s i i s o ma sim is ic way ookma ks ee e oug i o ma io o ec ea e e ocume as i was e y amic ege e a io i is esea c as a simi a u ose
Versioning: e sio co o as o g ee a co ce o i o ma io e ie a esea c a is ow a ce a issue o ma agi g i ua ocume s Use s may wa o e u o a o e sio o a i ua ocume a o a iga e o wa a ackwa i ime oug c a ges o a i ua ocume ookma ks usua y ake use s o e cu e e sio is o y i o ma io ee s o e eco e i o e o isi i e e e sio s o i ua ocume s
Search: ow o you sea c o i ua ocume s? e co e o ma y is o a ai a e o a co e - ase sea c i I sys ems W a is e omai i w ic o e o m e sea c ? W e wi e ocume e is o e use o e ie e i ?
Authentication: W o is es o si e o e qua i y o e co e s o a i ua ocume w e e com o e s may come om a a ie y o sou ces a /o ocesses?
Annotation: e o es o i o ma io use a i o ma io su ie a e me gi g ea e s e ec o e a e o a a a suc as comme s a o a io s a s a i ks w i e ey a e ea i g
Some esea c as ee co uc e o ese issues Ma i a Ek u (Ma i
1999 a Cauma s (Cauma s 1999 ea wi e c ea io o y amic ocume s y
e e i e em a es o k ow e ge Iksa a Ga a i (Iksa 1 esc i e a a a i e
We a ica io sys em w ic ge e a es a a i e i ua ocume s y mea s o a sema ic com osi io e gi e ase o use mo e s A i ua ocume is ge e a e y com u i g com o e s a a yi g a e e i e em a e o e isi i g u oses 51
is o y i o ma io is s o e a e i ua ocume is ookma ke Me a a a i o ma io a ou ocume agme s is s o e o e sio i g u oses e I
esea c i e s om (Iksa 1 i a e i ua ocume s a e c ea e y a a y ica a ica io s; e I sys em se s e use eques s o a ica io s aski g o ocume ge e a io a e ege e a io a so e e s o e a a y ica a ica io s W a is
esea c is a icu a y i e es e i is ow o y amica y ege e a e e i ua
ocume s a ow o eci e a e ege e a e o e is e same o e as e o e
i ua ocume s i I sys ems a e ge e a e o ema i es o se o use i u s e y e me ia i e ace ge s use i u s a e se s comma s a
a ame e s o a ica io s U e yi g a ica io s ge e a e sou ce ocume s e
y e me ia i e ace i e ce s e sou ce ocume s a e-i e i ies e e-ge e a e
ocume s As iscusse i C a e 3 r n r t n, r l t n a r d nt f t n a e equi e i I sys ems I sys ems a e simi a o ems e cou e e o i ua
ocume s esea c issues esc i e i e a o e sec io s E is i g me o s i i ua
ocume s esea c cou e a ie o I esea c O e o e a ow I sys ems
ea wi i ua ocume s wi o i e a i io a i sig s co ce i g e a o e
esea c issues i i ua ocume s
Document Structure
is sec io esc i es e y es o ocume s uc u e ocume em a es a s a a s o ocume s uc u e 5
4.2.1 Document Structure Overview
A ge e ic ocume mo e esc i es e s uc u i g u es o a ocume c ass I e i es i a ge e ic way ow s eci ic ocume s a e s uc u e I is i guis es ee y es o ge e ic s uc u es sema ic s uc u e ogica s uc u e a ayou s uc u e (Iksa 1
Semantic Structure: e sema ic s uc u e co eys e o ga i a io o e mea i g o e co e o a ocume
Logical Structure: e ogica s uc u e e ec s e sy ac ic o ga i a io o a ocume A ocume ca e oke ow i o com o e s (c a e s a i es a su com o e s (sec io s a ag a s
Layout Structure: e ayou s uc u e e ec s ow e ocume s ou e is aye suc as co o a o si e
HTML, SGML and XML
M SGM a M a e ma ku a guages o ocume s A com a iso o ese
ee a guages is as o ows
M ( y e e Ma ku a guage as a wi e y su o e ocume o ma i
e Wo Wi e We ca e c a ac e i e as ei g c ea sim e a i e e o ge e a use y a a ge au ie ce; u oo imi e o mo e a a ce y e me ia a ica io s M em e s y e i ks i e ocume s; i su o s o e ogica a
ayou s uc u e i e same M i e e way M ocume s ee o e ese e was i i ia y a -co e i o a We - owse ; a e is as ee c a ge y e i o uc io o CSS (Casca i g S y e S ee s
SGM (S a a Ge e a i e Ma ku a guage is mo e cus omi a e ( us
e i e a mo e " owe u " a e e e se o ei g mo e e e si e o im eme A
SGM ( ocume y e e i i io e i es e sema ic s uc u e SGM e i es
e ogica s uc u e a SSS ( ocume S y e Sema ics a S eci ica io 53
a guage [ SSS ] e i es ow ogica ocume s a e is aye e u ose o a
ocume y e e i i io ( is o e i e e ega ui i g ocks o a SGM
ocume I e i es e ocume s uc u e wi a is o ega e eme s W i e SGM
oes a e some u i e sa u es o i e e i g ocume s suc as ow a ocume y e
e i i io is s eci ie i as o i ui u es o ow o i e e ac o o is ay
y e e i ks — a is u o e i i i ua a ica io s a ei u e yi g ma ku
a guage o s eci y
M (E e si e Ma ku a guage was e e o e o i ge is ga e wee
M a SGM i k oi e a S ( e E e si e S y es ee a guage a e
o e a guages c ose y e a e o M i k a oi e e i e commo i k a
a essi g s uc u es w ic ca e use i M ocume s a S e i es a s y e
a guage o e i i g ow M ocume s s ou e ese e o e use M
e i es e ogica s uc u e a a a co e o e ocume A o M Sc ema
e i es e sema ic s uc u e o a M ocume M as ee wi e y acce e ue
o i s sim ici y o e ess s a a i e A Is o ma i u a e M ocume s (suc as
a si g a su o o a a ase
3 DOM
4.2.3.1 Overview. e ocume O ec Mo e ( OM is a a ica io
og ammi g i e ace (A I o a i M a we - o me M ocume s I
e i es e ogica s uc u e o ocume s a e way a ocume is accesse a
ma i u a e Wi OM og amme s ca ui ocume s a iga e ei s uc u e 54 a a mo i y o e e e e eme s a co e A y i g ou i a M o M
ocume ca e accesse c a ge e e e o a e usi g OM
e OM co e A I a ows so wa e e e o e s a We sc i au o s o access a ma i u a e a se M a M co e i si e co o mi g o uc s e OM
Co e A I a so a ows c ea io a o u a io o a ocume o ec usi g o y OM A I ca s; oa i g a ocume a sa i g i e sis e y is e o e o uc a im eme s
e OM A I
3 The DOM Structure Model. e OM ese s ocume s as a
ie a c y o o e o ec s a a so im eme o e mo e s ecia i e i e aces Some
y es o o es may a e c i o es o a ious y es a o e s a e ea o es a ca o a e a y i g e ow em i e ocume s uc u e o M a M
Acco i g o e OM a ocume is a ie a c ica s uc u e o o es o es a e o se e a y es u e e a e ee y es a a e ge e a y use e eme o es a i u e
o es a e o es e o es a e o ame u ca y e a i u e o es a e o a ame a ca y e a e eme o es a e a ame E eme o es may a e c i e ; a i u es a e o es a e e mi a I a i io e OM s eci ies ow o
eac e c i e o a e eme o e (suc as e a om e a e o a c i e a e eme c i e a e e i w a is esse ia y a a ay e i e i e a ay ei g
e e mi e y e o e o e su -e eme s i e ocume A i u e c i e a e e i a ic io a y e ame o e a i u e w ic mus e u ique wi i a e eme is use as e i e 55
4.2.4 Document Templates
ocume em a es a e e i e as se s o e- i ke ocume s a ca e u ica e
(Ca i 1991 A o e e i i io o a y e me ia em a e s a es a i is a a ia y- c ea e o e y o ma e co ec io o ocume ske e o s a ca e i e i y e use ( ao 199
em a es au oma e e ocess o c ea i g y e me ia co ec io s y c ea i g
e "ske e o s" o ocume s a i ki g em ey aci i a e e esig o ga i a io a ese a io o a co ec io o k ow e ge i e o m o y e e
e em a e ca e co si e e as a com osi e o ec com ise o o e o ec s suc as o es a i ks e usage o a em a e wi s ee u e ocess o a a e age use s u e s a i g o e u e yi g y e e mo e o e me a o Wi ou a
em a e a y e e au o wi a e o s a co s uc i g e y e e co ec io o i eas om e egi i g Ma y a ica io s suc as co a o a i e w i i g eac i g ai s e c a e some commo asis a ca e a s o me i o a y e e em a e
ocume em a es a e use o y amica y ge e a e i ua ocume s is i c u es
em a es o sema ic ogica s uc u e a ayou s uc u e Some a ica io s mi
ogica a ayou co e i o e em a e some uses em se a a e y ocume
em a es a e a so im o a i A a i e y e me ia ecause ΑΗ ge e a es y amic
ocume s ase o use mo e s e y e me ia em a es is e y use u o e ge e a io u ose 56
4.2.5 Document Structure in JIT Systems
In JIT systems, the document template is for regeneration purposes. This includes templates for content and layout. The content template is for transforming the source documents, which are generated by the underlying application, into an XML document.
The layout template is supplied to display the XML document on the Web browser. The semantic information is represented by a DTD or XML Schema file.
4.3 Adaptive Hypermedia
Adaptation/personalization is one of the main issues for Web applications since the late
0s. e a a i e y e me ia (ΑΗ commu i y a ose a y om e e e si e wo k that had already been conducted into artificial intelligence (Al) and partly from
I e ige u o i g Sys ems (I S . ΑΗ esea c e s a e ima i y co ce e wi usi g pre-existing methods and techniques found in the fields of Al, ITS and user modeling, and extending, combining and merging these ideas to create systems that understand and aid the user in knowledge acquisition (Bailey 2002).
ITS promoted the development of educational server-side adaptive Web-based systems such as MANIC, INTERBOOK (Brusilovsky 1998) and AHA (Paul de Bra
1998). Other such server-side systems index Web sites or provide personalized interfaces to large hypermedia systems. MANIC is an open-source, cross-platform system to create and deliver courses over the WWW. MANIC allows instructors to create courses and deliver them to students as HTML slides shown in synchrony with the voice of the instructor in an audio system. AHA is a generic adaptive hypermedia system, which consists of an engine which maintains a user-model based on knowledge about concepts.
ΑΗ as a so see e e e o me o c ie -si e a a i e sys ems a o ow users as they browse the WWW. Examples of these systems include WebMate (Chen
1997), Letizia and LiveInfo (Maglio 2000). WebMate keeps track of user interests in different domains (concepts) and these domains are automatically learned by WebMate.
WebMate automatically extract keywords for refining document search. During search, the user can provide multiple pages as similarity/relevance guidance for the search.
WebMate extracts and combines relevant keywords from these relevant pages and uses them for keyword refinement. Using these techniques, WebMate provides effective browsing and searching help and also compiles and sends to users personal newspaper by automatically spiting news sources. Letizia is a user interface agent that assists a user browsing the World Wide Web. As the user operates a conventional Web browser such as Netscape, the agent tracks user behavior and attempts to anticipate items of interest by doing concurrent, autonomous exploration of links from the user's current position. The agent automates a browsing strategy consisting of a best-first search augmented by heuristics inferring user interest from browsing behavior.
Brusilovsky (2000) divides adaptive hypermedia into two distinct areas: adaptive presentation and adaptive navigation support. Adaptive presentation systems rely on information chunks (or fragments) that can be processed and rendered in a variety of ways depending on user preferences. Adaptive navigation support includes direct guidance, adaptive link sorting, adaptive link hiding, adaptive link annotation, adaptive link generation, and map adaptation. 58
A a i e sys ems a e y ica y ocuse o e a a i e ese a io o co e a i ks ase o use mo e s (Cu i e Use mo e i g e ca u e o i o ma io a ou e use suc as ei k ow e ge asks a i u es a i e es s cou
e i eg a e i o a a i e y e me ia sys ems o im o e use e icie cy ( ai ey 1
(Iksa 1 ge e a es a a i e i ua ocume s o au o -o ie e We a ica io s
o i i g se e a ea i g s a egies o ea e s A a a i e i ua ocume ca e com u e o e y y mea s o a sema ic com osi io e gi e usi g a o e a
ocume s uc u e; a i e ige sea c e gi e sema ic me a a a; a e use mo e
( ai ey 1 ese s a ec ique o c oss- omai a a i e a iga io a su o y com i i g i k augme a io wi a mo e o e use s s a ia co e (Ca a a o 1
ese s a g a - ase aye e mo e o esc i i g e ogica s uc u e o e
y e me ia I a so ese s M - ase mo e s o esc i i g me a a a a ou asic i o ma io agme s a " eu a " ages o e a a e is a a i e y e me ia sys em is mo e e wi es ec o ee i e e ime sio s esc i i g use s e a io ec o ogy a e e a e i o me
A a i e y e me ia sys ems y amica y ge e a e ocume s ase o use mo e s A oug ey a e o ea i g wi y amic ege e a io ec iques a ou
ocume em a e esig a ocume s uc u e ecog i io i ese sys ems cou e a ie o y amic ege e a io i " us -i - ime" y e me ia esea c
4.4 U ique I e i ie s
4.4. O e iew
Unique identifiers are essential for digital objects and intellectual property. Brian Green and Mark Bide (Green 1997) give an overview of why the publishing industry needs identifiers and describe some existing standards of unique identifiers.
Unique identifiers are also crucial for object identification in hypermedia systems.
As discussed in Chapter 3, unique identifiers are necessary for virtual documents and virtual elements in JIT systems. Section 4.4.1 describes some definitions about unique identifiers, requirements for designing identifiers. Section 4.4.2 and Section 4.4.3 describe existing unique identifier systems, such as URI and OI. Section 4.4.4 compares comparisons among these identifiers and introduces unique identifiers in JIT systems.
4.4. . Some Co ce s. Some basic concepts about identifiers are described as follows:
I e i ie : a character or group of characters constituting a value which is used to distinguish one entity from another. (CCS S 2000)
ames ace: a set of unique values which serves as identifiers for a corresponding set of entities. (CCS S 2000)
U ique: unambiguous in a given namespace. An identifier must specify one and only one object in that space (Paskin 1999).
e sis e : identifiers must have an unlimited lifespan even though the objects they identify may not (Paskin 1999).
G a u a i y: to what level of detail does the content be identified (Green 1997).
ea a i i y: identifier syntax in a way to aid interpretation by human inspection in an application (Paskin 1999). 60
Dumb (unintelligent) identifier: a purely random number which can only be interpreted by reference to a central database. The number itself does not contain any meaning or information about the object which it identifies (Green 1997).
Intelligent identifier: an identifier string which serves both as a unique label and also has some meaning or information related to the object itself (Paskin 1999).
Resolution: a process in which a unique identifier is the input (a request) to a system to specify some specific output (such as the resource location) (Paskin 1999).
4.4.1.2 Some Issues and Design Requirements. Several issues about designing unique identifiers are discussed in (Powell 1997), which are listed as follows:
Granularity: What level of granularity is required? For example, traditional publishers have worked at the book or journal level using the International Standard Book Number (ISBN) and International Standard Serial Number (ISSN) as identifiers, while the Digital Object Identifier (DOI) system provides identifiers for fragments of documents.
Dumb or intelligent identifier: What degree of intelligence does the identifier provide? Some software systems use dumb identifiers and users can not get related information about objects from identifiers. For example, the Microsoft Windows operating system creates unique identifiers for IDL (Interface Definition Language) projects. Each identifier is a combination of alphabets and numbers that carrying no meaning. However, most identifier systems have some degree of intelligence.
Identification and location: An identifier is a label while location is the physical position of the object. A true identifier must remain the same regardless of the location. The URL (Uniform Resource Locator) in this sense is not a real identifier.
Persistent: How long should an identifier need to last? Internet identifiers need to outlast current Internet technology and computer systems.
Besides these issues, Paskin (1999) discusses design requirements for unique identifiers such as uniqueness, international, neutral, persistent, ease of use in automated systems, granularity. Neutral means identifiers should not be tied to a specific application and should be able to function as a common identifier for a range of applications. Ease of use in automated systems requires identifiers to have a prescribed syntax to be able to be parsed by computers. These requirements should be used to evaluate existing identifier systems and to design unique identifiers in JIT systems. 61
URI (Uniform Resource Identifier)
4.4.2.1 URI Overview. U i o m esou ce I e i ie s (U I a e s o s i gs a i e i y esou ces i e We ocume s images ow oa a e i es se ices e ec o ic mai o es a o e esou ces U Is make esou ces a ai a e u e a a ie y o ami g sc emes a access me o s suc as a I e e mai a essa e i e same sim e way
A U I is a com ac s i g o c a ac e s o i e i yi g a s ac o ysica
esou ces U Is a e c a ac e i e y e o owi g e i i io s
Uniform: U i o mi y o i es se e a e e i s i a ows i e e y es o esou ce i e i ie s o e use i e same co e e e w e e mec a isms use o access ose esou ces may i e ; i a ows u i o m sema ic i e e a io o commo sy ac ic co e io s ac oss i e e y es o esou ce i e i ie s; i a ows i o uc io o ew y es o esou ce i e i ie s wi ou i e e i g wi e way a e is i g i e i ie s a e use ; a i a ows e i e i ie s o e euse i ma y i e e co e s us e mi i g ew a ica io s o o oco s o e e age a e-e is i g a ge a wi e y-use se o esou ce i e i ie s
Resource: A esou ce ca e a y i g a as i e i y ami ia e am es i c u e a e ec o ic ocume a image a se ice (e g " o ay s wea e e o o os A ge es" a a co ec io o o e esou ces o a esou ces a e e wo k " e ie a e"; e g uma ei gs co o a io s a ou ooks i a i a y ca a so e co si e e esou ces e esou ce is e co ce ua ma i g o a e i y o se o e i ies o ecessa i y e e i y w ic co es o s o a ma i g a a y a icu a i s a ce i ime us a esou ce ca emai co s a e e w e i s co e --- e e i ies o w ic i cu e y co es o s---c a ges o e ime o i e a e co ce ua ma i g is o c a ge i e ocess
Identifier: A i e i ie is a o ec a ca ac as a e e e ce o some i g a as i e i y I e case o U I e o ec is a seque ce o c a ac e s wi a es ic e sy a a i g i e i ie a esou ce a sys em may e o m a a ie y o o e a io s o e esou ce suc as "access " "u a e " " e ace " o " i a i u es " 62
A U I ca e c assi ie as a oca o a ame o o e U (U ique esou ce
oca o e e s o e su se o U Is a i e i y esou ces ia a e ese a io o ei
ima y access mec a ism (e g ei e wo k " oca io " a e a i e i yi g e
esou ce y ame o y some o e a i u es o a esou ce
e U (U ique esou ce ames ace e e s o e su se o U I a a e
equi e o emai g o a y u ique a e sis e e e w e e esou ce ceases o e is o ecome u a ai a e
4.4.2.2 URL (Uniform Resource Locator). U s a e e mos wi e y use i e i ie s i I e e I e o owi g e U I sy a a e am es a e e ami e o s ow ow U s mee e i e i ie esig equi eme s
• URL Syntax
e U sy a is e e e u o a sc eme I ge e a a so u e U s a e w i e as o ows sc eme sc eme-s eci ic- a Mos o e U s s a e a commo sy a o e ese i g ie a c ica e a io s i s wi i e ames ace is "ge e ic U " sy a co sis s o a seque ce o ou mai com o e s sc eme // au o i y a ? que y Eac o w ic e ce sc eme may e a se om a a icu a U
• Specific Schemes
e U I s eci ica io co e s e o owi g sc emes i e a s e o oco y e e a s e o oco go e e Go e o oco mai o E ec o ic mai a ess ews USE E ews USE E ews usi g access e e e e e ce o i e ac i e sessio s wais Wi e A ea I o ma io Se e s i e os -s eci ic i e ames os e o os e o i ec o y Se ice 63
• Example URL ftp://ftp.is.co.za/rfc/rfcl χ ftp scheme for File Transfer Protocol services. "ftp:" is the schema name, the other part after "II" is the schema-specific part. gopher://spinaltap.micro.umn. edu/00/Weather/California/Los %20Angels gopher scheme for Hypertext Transfer and Gopher+ Protocol services. "gopher:" is the schema name, the other part after "//" is the schema-specific part.
From above syntax and examples, it can be conclude that URLs are intelligent, international, neutral, unique, easy to use in automated systems and have fine granularity.
Α U is i e ige ecause i co ai s mea i g u i o ma io a ou e o ec I e first example, the object is a text file, which exists in the server "ftp.is.co.za" and the user should use ftp protocol to access the file. URLs are international and neutral because they incorporate many different schemas and they are used widely all over the world. URIs are unique, there is one-to-one relationship between the URI and the object. URIs are easy to use in an automated system such as the WWW. URIs use file system concepts like hierarchy to achieve granularity at the document level. However, URLs are not persistent, which causes the "dangling link" problem on Web. This leads the URN and
PURL efforts to achieve persistence.
4.4.2.3 URN (Uniform Resource Namespace). URNs are intended to serve as persistent, location-independent, resource identifiers.
• Syntax
• Example urn:isbn: 2 4 6 8 Χ urn:telecom:61733654310 The first URN shows support for the existing ISBN scheme used by the publishing industry. The second URN shows an (hypothetical) example of an international telecommunications carrier and a particular individual's telephone number.
• URN Resolution Service
The URN resolution service provides the functionality that allows clients who have a URN to locate the resource it refers to, or to find the associated URC (Uniform Resource Characteristics) (Iannella 1996). A URC is a set of attribute pairs describing a resource. The client contacts the resolver service, asking it to resolve the URN. The resolver finds the URC corresponding to the URN and returns that information to the client. The information in the URC may include the location of the resource itself, which the client can use to retrieve the resource.
URNs are intelligent, international, neutral, unique, persistent, easy to use in automated systems and have fine granularity. The URN system has incorporates some application systems but is still under development and not widely used.
4.4.2.4 PURL (Persistent Uniform Resource Locator). The Persistent Uniform
Resource Locator (PURL) was developed and implemented by the Online Computer
Library Center Inc. (OCLC) as a naming and resolution service for general Internet resources. It is intended as an interim system to be used until the URN framework is well established. A PURL looks just like a URL, except that it points to a resolution service instead of the actual location of the digital resource. Below is a PURL example:
http://purl.ocic.org/OCLC/PURL/FAQ
"http" is the protocol, "purl.ocic.org " is the resolver address, "OCLC/PURL/FAQ" is the resource name. The client sends the PURL address to the PURL server, and the PURL server sends the real URL back to the client. Then the client can complete the URL transaction in the normal fashion. 65
3 DOI (Digital Object Identifier)
4.4.3.1 Overview of DOI 2001. e igi a O ec I e i ie ( OI o igi a e i 199 is a sys em o
• I e i yi g a e c a gi g i e ec ua o e y i a i e o e a e igi a e i o me ;
• o i i g a e e si e amewo k o ma agi g i e ec ua co e i a y o m a a y e e o g a u a i y a i ki g cus ome s wi co e su ie s;
• aci i a i g e ec o ic comme ce a ;
• E a i g au oma e co y ig ma ageme o a y es o me ia
e OI o i es a s a e e sis e i k e wee co e a a i ec o y o e
I e e o w ic e co e ow e wis es e OI o oi As a e sis e i e i ie
e OI as a a ages o e a o - e sis e U i o m esou ce oca o (U U ike a U w ic oi s o a iece o co e ase o i s oca io o a com u e co ec e
o e I e e e OI i e i ies a iece o co e y a e ma e um e a is i e e e a a e e c a ges o ce i is assig e o e co e e OI oi s o a ce a i ec o y o e I e e w ic i u e i ec s e use s owse o e cu e oca io o e s eci ie co e I is a so ossi e o a OI o e e e ce co e
a oes o e is i s a ic o m i e oes o e is as a s eci ic i e o a I e e se e I a i io o i s c a ac e is ics o e sis e ce e OI as a sy a a o e y
e Ame ica a io a S a a s I s i u e a ca aci i a e e c ea io o a u ique u am iguous I o eac e eme i a wo k a a y e e o g a u a i y o e am e e
OI ca i e i y a e i e ook o maga i e i i i ua c a e s o sec io s i us a io s o a es 66
e OI o i es is e sis e i k y o i i g a eso u io -a - ou i g sys em simi a i co ce o e I e e s omai ame Sys em ( S A S sys em mai ai s a a e eco i g e I (I e e o oco a ess (w ic is usi g u ique 3
igi s a e 1 i s i I a omai ame Usua y a omai ame is e ese e y a U A use uses e omai ame o isi e We si e e S eso es omai
ames o u ique I a esses e e S akes e use o e ig oca io (I a ess A omai s oca io cou c a ge o e am e a com a y may use a i e e se e (w ic as a u ique a ess o os e We i o ma io u use s s i ca
isi e same com a y s ome age oug e S eso u io oce u e
3 e S uc u e o OI. e OI sys em as wo a s — e " OI age cy" a e " OI c ie " e OI age cy assig s u is e I s issues gui e i es o OI usage a wo ks wi e e e a s a a s o ies o mai ai e i eg i y o e sys em as a w o e e OI c ie s o m a is i u e sys em a eso es a y OI o i s associa e U
e OI sys em is ase o e o osa a u is e s s ou u i o m y a o
o ma o s a a um e i g sc emes o ei o i e o uc s; e cu e ee i g is
a e is i g egacy sys ems suc as e IS ISS o ISWC (I e a io a S a a
Wo k Co e s ou e use as a asis o is um e i g Suc um e e o uc s a
ei o i e a esses wi e egis e e i a o i e i ec o y o a a ase w ic wi au oma ica y ou e que ies a ou a o uc o e co ec oca io o a o uc w e e
u is e s es o se sc ee s wi au oma ica y o e e e qui e a a ie y o comme cia
a sac io o io s suc as iewi g u c asi g ice si g o u e ou i g o e am e om a a ic e a s ac o u a ic e co e s 6
The DOI number will be embedded in the product itself, and becomes the chief retrieval mechanism for that object, by means of clicking on a " DOI button" in a publisher's list, in a bibliographical reference, in the DOI directory itself, or in a library if the library has purchased or licensed access to the document. The product can be as large as an encyclopedia or as small as an abstract or a graph in an illustrated scientific research article, since the publisher may choose to trade on any level of document granularity, and may therefore number as many works and 'fragments' of works as desired. Any change in the location of a registered online product or object must be forwarded by the copyright owner of the object to the online DOI directory database so that it may be updated. Enquiries will be routed seamlessly by the directory to the latest online address of an object by this method of indirect resolution. The underlying technology for this central DOI directory is called the Handle system (Handle 1997).
When it receives a DOI request from a user's browser, it translates or "resolves" that DOI to the specific location which the publisher has specified for it, and then automatically re- routes the user's browser to that location.
4.4. . OI um e i g (Maree 1998). The DOI numbering system leans heavily on current print numbering schemes, with added digits indicating the registration agency and the copyright owner.
The DOI has two components, known as the prefix (publisher ID) and the suffix
(content ID). These are separated by a forward slash. A typical DOI number may read as follows: 68
0. 2 4 [IS ]0 4 6 8 Χ
is cou i ica e e o igi a OI egis a io age cy (1 e o igi a co y ig ow e o egis a (1 3 e um e i g sys em a was use [IS ] a
e o uc i se ( -333- 5 7 -Χ
A e a i g OI um e i g s i g o a i e a y e i ase o e ISWC a oac cou ea as o ows
10.540/142756081/[IS W C] -L-054.000.015.4
is wou i ica e e OI issui g au o i y (1 e e i assig e y e
OI age cy o e ig s o e (5 e CAE um e (1 75 1 (w ic is a
au o s um e e um e i g sys em co e (ISWC a a ISWC um e o a i e a y
e (- - 5 15
4.4.4 Unique Identifiers in JIT Systems
Acco i g o ( aski 1999 asic equi eme s o i e i ie s a e u ique ess
e sis e ce i e ige ce i e g a u a i y g o a sco e e c (see Sec io 1 U s
a e u ique o e sis e i e ige u a e i e g a u a i y a g o a sco e U s
a e e sis e owe e U s i eg a e e eso e s a ess wi e U is
a ows o y o e eso e o e sys em U s o y se e as a i e me ia e oo w e
U s a e s i i e amewo k ocess U s a OIs a e u ique e sis e
i e ige a a e i e g a u a i y a g o a sco e
I e i ie s i I sys ems s ou e u ique e sis e i e ige a easy o use
i au oma e sys ems a a e i e g a u a i y i ua o s a ic ocume s a e eme s
i ocume s s ou a e u ique e sis e i e i ie s o e e e ce u oses
y e me ia o ec s (suc as a c o s i ks ookma ks a o a io s a so s ou a e 69 unique, persistent identifiers. Because hypermedia objects are stored in an external database, identifiers are necessary for reference purposes. JIT systems integrate multiple applications; therefore each application could be treated as a namespace. The JIT hypermedia engine assigns a unique ID for each application. This is similar to URN and
DOI systems; the URN system assigns a NID for each namespace; the DOI system assigns a publisher ID (prefix) for each publishing organization. In a URN, the
JIT systems, IDs for documents, elements, and hypermedia objects are all assigned by the hypermedia engine; not by applications. IDs in JIT systems should have fine granularity because elements and hypermedia objects are based on documents, and elements could be any part of the document. Intelligence and ease of use are important because this makes it easier and efficient to create and maintain IDs in JIT systems.
4.5 Object Identification and Addressing Mechanisms
4.5.1 Overview
Object identification is for locating the predefined anchors and identifying the displayed contents as the same one as one previously encountered. An anchor is a selected element
(words, a sentence, a paragraph or anything else) in a document, including the entire document itself. An anchor could have three different degrees of scope: specific, local
and generic (Davis 1995[1 ] ).
Specific: only applies to that particular instance of the element in that particular document.
Local: applies to any instance of that particular element in that particular document. 0
Ge e ic: a ies o a e i s a ces o e same e eme s i a ocume s
Usua y e a c o i o ma io co ai s a u ique i e i ie (o ame a a
oca io s eci ie e oca io s eci ie i ica es e osi io a co e o e se ec e a ea i e o e o e am e i a e i e i a use se ec s a s i g om y e o se 1
o y e 11 e co e is e 11 c a ac e s om y e o se 1 o y e o se 11 e
oca io is 1 i e sys em uses y e o se o eco oca io s is a c o cou a e
ame assig e y e use
ow a y e me ia sys em assig s e a c o i o ma io a w e e is i o ma io is s o e a ies amo g i e e sys ems M ocume s i e
a i io a WWW sys em em e a c o i o ma io A c o s s eci yi g ou goi g i ks
o ma y o o a e i e i ie s o ames; e co e is su ou e y ags a e e ac
ace o e se ec io e e o e e e is o ee o eco e co e a oca io i o ma io I mos y e me ia sys ems suc as M (G ø aek 199 a Mu iCa
( i k 199 a c o i o ma io is s o e i a e e a a a ase; w e a use a e ses a
i k e a c o i o ma io ee s o e eso e e y e me ia sys em mai ai s a
a e o I s a oca io s eci ie s (co e a oca io W e e e is a eques o
eso e e a c o i o ma io e y e me ia sys em uses e a c o I a sea c es
e co es o i g oca io s eci ie i o ma io o a a c o
e e a e se e a ways o e ess oca io s i si e a e i e ese i c u e
• ami g -- e g a e eme ame o i ;
• Cou i g - e g e 3 y e i is i e o e i em i is is ;
• Que yi g - e g e i s i em wi a y e a i u e w ose a ue is 1
There are many standards and protocols using different methods to record locations. In the following sections, several addressing schemes in detail are described, such as HyTime, OHP and XPath.
4. .2 y ime
e Ηy e me ia/ ime- ase S uc u i g a guage ( y ime o i es aci i ies o representing static and dynamic information that is processed and interchanged by hypertext and multimedia applications. HyTime is an application of the SGML (Standard
Generalized Markup Language). HyTime provides standardized mechanisms for specifying interconnections (hyperlinks) within and between documents and other information objects, and for scheduling multimedia information in time and space.
The HyTime location address module allows the identification of objects that cannot be addressed by SGML unique identifiers, and objects that are in external documents. Three basic types of address may be supported: name, semantic location and coordinate location. Addressing of multiple locations (a list of locations) is also possible.
The syntax and semantics of these addressing mechanisms are independent of the data content notations of the data being addressed.
4. .2. oca io s i y ime (Reich 1997). HyTime distinguishes the following types of location addressing: name space locations, coordinate locations, and semantic locations.
• ame S ace oca io s
Name space locations in HyTime can either be done by a) referencing a local element by its ID using IDREF (a tag in SGML to indicate that this is the unique ID in a SGML file), or b) by referencing a named object. For the latter the element-type nameloc is used. Instead of a single name, a name list can be used. Thus, multiple end points are possible. 72
• Coordinate Locations
Coordinate locations are used for addressing one or more sequences of data by a relative position. HyTime supplies for the following architectural forms (basic building blocks which can be re-used by different document type definitions):
1) Bit combinations, being addressed by d t l , for example, representing characters in a character string.
2) Tokens, such as words, names, numbers, within a token list using d t l .
3) Nodes in a tree structure, being addressed either by a tr l or a p thl .
• Semantic Locations
HyTime distinguishes the semantic locations as three types: pr p rt location address, n t t n p f location address and b bl r ph location address. r p rt locations can be used for addressing the value of a named property of an object. Νοt t n p f addressing is done by issuing a query in a specific (not HyTime defined) notation. Lastly, b bl r ph addressing means addressing objects that the system cannot access automatically, for example, a printed book on a shelf.
• Querying
A dynamic method of addressing is through queries, where the exact location is not known but resolved through matching against properties in real time. HyTime defines a query language (HyQ) which has since been superseded by the DSSL query language (SDQL).
The HyTime standard was introduced as a general format to cover hypermedia structures as well as synchronization mechanisms for time based content. However, due to its complexity, these formats have not been put into widespread use.
4.5.3 Microcosm, OHP and OHIF
4.5.3.1 Microcosm. Microcosm (Davis 1995 [ 1 ]) is an open hypermedia system which can generate "computed links" in the early 1990s. Microcosm defines the difference between an n h r (a hypertext object which describes one end of a link) and a p r t nt l t n (that object within the node data which is the physical manifestation o e i k a c o suc as a co o e e s i g Wi e i es Mic ocosm s mai a oac o a essi g a a c o is usi g y e o se ( a is 199511] is ca ea o
e i e-e i i g o em w ic causes ossi e i k i co sis e cy W e a s a ic i e is e i e i ks associa e wi is i e cou ecome i a i Mic ocosm uses a e a
ime s am s o i ica e a e i e co e as ee c a ge a wa s use s a ou e
ossi e i k i co sis e cy o e oca e e a c o s e o wa o se a e e se o se o e a c o a e use Some co e (usua y 1 c a ac e s su ou i g e a c o is s o e W e e a c o ca o e ou i e e ious oca io Mic ocosm sea c es
e i e o a occu e ces o e co e I o y o e occu e ce is ou Mic ocosm assumes i is e same a c o a e i k is e oca e o is ew oca io
5 3 O (O e y e me ia o oco ( a is 199 e O e y e me ia
o oco (O is a o oco o commu ica io s e wee a ica io s a y e me ia
i k se ices I e i es e o ma o a c o s commu ica io o oco s a messages
om a o i e e a ica io s A a c o is esc i e as a i i g e wee a com o e i e i ie a a l t n p f r ( ocS ec A ocS ec co ai s e e ai s w ic esc i e a e sis e se ec io a e sema ics o ese e ai s a e eci e y
e a ica io a e ime a e a c o is c ea e a eso e usi g e same a go i m w e e a c o is oa e agai a a a e ime
e i icu y i e i i g a s a a ocS ec is a i i is o e su icie y
e i e o mee a ossi e ways o e essi g osi io s i a ocume as i e e y
e y ime s a a (see Sec io 5 e i wi e i icu o a se a us u s co si e a e o us o e a ica io O e i es a ocS ec as o ows 4
ocS ec = { Co e y e Mime y e Co e Mime e co e e s i g Cou [Comma se a a e is o um e s] e e seCou [Comma se a a e is o um e s] ame [Mime e co e e s i g] Sc i [ iewe E ecu a e Sc i ]
e im o a i g o ea i e a ou e ocS ec is a a oug e i k se ice may e equi e o s o e is i o ma io i is o usua y equi e o i e e e i o ma io i a y way e sema ics o e a ious ie s wi i e ocS ec a e
eci e y e iewe a e ime a i c ea es e ocS ec a e s o e i e i k se ice o a e e ie a a i e e a io y e same iewe us i e e iewe s a e o equi e o kee o a y a icu a co e io o e ese i g ese ie s
ocS ec is o o io a e o oco equi es a e ocS ec co ai s a eas o e me o o e iewe o s o e i o ma io a ou e osi io o a a c o
e comma se a a e is o um e s use i e cou a e e se cou wi
e e o e me o use y e iewe o e ese osi io s i ocume s e g 3 ,
3 mig e use y a s uc u e ocume o mea e 3 c a ac e i e 5
a ag a o Sec io 3 A e a i e y i mig e ese e o e a o om ig co- o i a es o a ec a g e i a i ma
e e e se o se a ows us o e ese a osi io y cou i g om e e o a
ocume is o e oa i g ca e use u w e yi g o i ocS ecs a a e ecome
oke ue o ocume e i i g e sc i e i es a e ecu a e comma i e e e
y e iewe i o e o oca e a o io o e co e s e ame may e a y o ec u e s oo y e iewe w ic is u ique o e cu e ocume suc as a ookma k
ame o a awi g o ec
4. . . O I (O e y e me ia I e c a ge o ma . (Grønbaek 2000) introduces an approach to utilize open hypermedia structures such as links, annotations, collections and guided tours as metadata for Web resources. This XML based data format is called the OHIF (Open Hypermedia Interchange Format), for such hypermedia structures. OHIF stores anchor information externally in an XML file based on the OHP addressing structure.
Eac O I i e e ese s a "co e " o ec o e a a mo e Α co e is a
(indexed) collection of other hypermedia objects. OHIF represents nodes, links, anchors, endpoints and other hypermedia objects by XML format. Each object has attributes of
"id", "type" and "name". The identifier is unique.
OHIF links are general many-to-many relationships as supported first in the
Dexter model and HyTime. For multidirectional links, the OHIF link carries a collection of endpoints. OHIF endpoints are responsible for addressing the anchor which is responsible for keeping the LocSpec for a specific location inside a node's content.
Endpoints also hold a direction attribute, with information about whether the endpoint is considered as a source, a destination or both.
4. .4 a a oi e
4. .4. a . XPath is the result of an effort to provide a common syntax and semantics for functionality shared between XSL Transformations (XSLT) and XPointer.
XSL is the stylesheet language to specify the display layout of a XML document. XSLT is the language to transform one XML document to different layout according to different
XSL file. The primary purpose of XPath is to address parts of an XML document. In support of this primary purpose, it also provides basic facilities for manipulating strings, 76
um e s a oo ea s a uses a com ac o - M sy a o aci i a e use o a wi i U Is a M a i u e a ues a o e a es o e a s ac ogica s uc u e o a M ocume a e a i s su ace sy a
a mo e s a M ocume as a ee o o es e e a e i e e y es o
o es i c u i g element o es attribute o es a text o es a e i es a way o com u e a s i g- a ue o eac y e o o e Some y es o o es a so a e ames
a u y su o s M ames aces (a e i e se o M e eme s us e ame o a o e is mo e e as a ai co sis i g o a oca a a a ossi y u ames ace
U I is is ca e a e a e - ame
• Examples
e asic a sy a is simi a o i e sys em a essi g I e a s a s wi / e i e ese s a a so u e a o e equi e e eme Simi a o y ime a as ami g cou i g a que yi g me o s o s eci y e e eme s i a M i e
e ocume e ow ( igu e 1 A mi m e ese s a use w o as a use i a a asswo Mo eo e a use ca a e mu i e o es i is case wo Domain Administrator a Help Desk Administrator:
Figure 4.1 A mi m
e o owi g a e some a e essio s a s eci y i ems i si e a mi m e e si e is e a e essio e ig si e is e e a a io o e e essio 77
/user/userid/text() select `someone' /user/roles/role select all `role' elements //role select all `role' elements //role [ @ id=' admin' ]/text() select `Domain Administrator' /user/roles/role[ 1 ] select the first role element, i.e., `Domain Administrator' /user/roles/role[lastO] select the last role element, i.e., `Help Desk Administrator'
4.5.4.2 XPointer. XPointer is the language to be used as the basis for a fragment identifier for any URI reference that locates an XML resource. It is based on the XML
Path Language (XPath), and supports addressing into the internal structures of XML documents. It allows for examination of a hierarchical document structure and choice of its internal parts based on various properties, such as element types, attribute values, character content, and relative position.
• Examples
XPointer uses some commands such as id, range-to, and string-range to specify arbitrary strings or characters in an XML file. The following are some examples of XPointer expressions and the explanations.
XPointer(id("chapl ")/range-to(id("chap2 "))):
- locates the range from the start-point for the element with ID "chap 1" to the endpoint for the element with ID "chap2".
- selects the fifth exclamation mark in any text node in the document and the character immediately following it.
4.5.5 Object Identification in JIT Systems
HyTime is a complex and flexible addressing mechanism based on SGML. While SGML has not been widely accepted due to its complexity, HyTime has the similar situation.
OHP is a pretty simple addressing mechanism. It uses the forward and backward offsets in the file to record the location. But it cannot reflect the document structure information. 78
OHIF uses an XML format to describe the hypermedia composites based on the OHS data model. The advantage is it gives meta-information about different hypermedia composites and it can address to non-XML file. However, the disadvantage is that it uses the absolute offset to record the anchor position in the file. Then if the editing problem occurs, or if the document content changes, this will become a dangling link.
In "just-in-time" environments, the virtual documents are the objects being dealt with, in which the re-location and re-identification problems are solved based on the document structure. For example, if an element's value changes, it could still be treated as the same element based on the revalidation criterion discussed in Section 3.4.2. In this case, semantic information about documents and elements in documents is needed. The
XPath/XPointer supplies a flexible addressing mechanism for XML documents based on the document semantic structure. Also it is possible to address non-XML documents by this standard. Thus the author considers the XPath/XPointer standard to be the appropriate addressing mechanism for "just-in-time" hypermedia systems. CHAPTER 5
THE JUST-IN-TIME HYPERMEDIA ENGINE
o im eme a e a ua e e us -i - ime y e me ia amewo k e I y e me ia e gi e ( E is esig e ase o e y amic y e me ia E gi e ( E A
y e me ia e gi e is a y e me ia i e ace a ca su eme a ica io s wi
y e me ia se ices Sec io 5 1 esc i es se e a y e me ia e gi e sys ems i c u i g
Mic ocosm eck es - a iga o We ise S a I i i e Sec io 5 esc i es
e y amic y e me ia E gi e ( E i e ms o i s a c i ec u e a com o e
u c io a i y E is a y e me ia sys em a ca su y y e me ia se ices o a a y ica a ica io s y i e ce i g ocume s e wee a ica io com u a io a
e use i e ace E ca au oma ica y ge e a e i ks ase o e a ica io s u e yi g e a io s i s E is a e e sio o E o su y y e me ia u c io a i y
o i ua ocume s Sec io 5 3 esc i es e I y e me ia E gi e i e ms o i ea a c i ec u e i o ma io ow a im eme a io e ai s Sec io 5 3 1 esc i es e
E a c i ec u e w ic is e e e sio o e E a c i ec u e ew com o e s a e a e o e E a c i ec u e o su o y amic ege e a io e- oca io a e- i e i ica io ese com o e s a e e i e i Sec io 5 3 (a im eme a io e ai s gi e i Sec io Sec io 5 3 3 uses a owc a o e ic e i o ma io ow o
i e e si ua io s Sec io 5 esc i es im eme a io e ai s o eac ew mo u e i
E
79 80
5.1 Hypermedia Engine Overview
To supplement applications with hypermedia functionality, a hypermedia engine is needed to model and maintain application-specific hypermedia structures. Hypermedia engines execute independently of an application, and provide the application's users with hypermedia support. Notable projects include Microcosm's Universal Viewer (Davis
1994), Freckles (Kacmar 1995), the 00-Navigator (Garrido 1996), WebVise (Gr^cnbaek
1999), SFX (Van de Sompel 1999) and InfiniTe (Anderson 2001). Details about these hypermedia engines and evaluations for them will be described in Chapter 7.
5.2 Dynamic Hypermedia Engine (DHE)
5.2.1 Analytical Applications
Analytical or computational applications logically can be split into two parts: the computational part that performs calculations and generates screens and documents for display; and the user interface — the users' viewer or browser that displays the screen or document (Bieber 1995). Microcosm's Universal Viewer and Freckles seamlessly integrate with applications but provide only manual linking. 00-Navigator provides a seamless hypermedia support for computational systems that execute within a single
Smalltalk environment. The Dynamic Hypermedia Engine (DHE) (Galnares 2001) supplies dynamic linking that applies to any Web-based service (including, but not exclusively, "Web services"). The Just-in-time Hypermedia Engine (JHE) extends the concepts in DHE for just-in-time hypermedia and fully supports hypermedia for virtual documents. 81
5 DHE Architecture
o su eme a a y ica a ica io s wi y e me ia u c io a i y e y amic
y e me ia E gi e ( E (Ga a es 1 i e ce s ocume s a sc ee s as ey a e a ou o e is aye o e owse a i g i k a c o s y amica y o e e eme s i ca ecog i e W e e use se ec s o e o ese su eme a a c o s E ge e a es a se o e e a i ks C oosi g o e o ese i ks om s E o se a comma
(e g a que y o e a ge a a y ica a ica io a wi cause i o ge e a e a i ua
ocume co ai i g e ca cu a io esu s e a ge a ica io ca e e same o e
a ge e a e e o igi a is ay o a i e e o e E ca o e o i e is su eme a y e me ia u c io a i y wi mi ima o o c a ges o e a a y ica a ica io s oug e use o a ica io w a e s (Ga a es a aumik 1
A w a e is a i e ace e wee e y e me ia e gi e a e a ica io w ic me ia es e wee em W a e s a e esc i e i mo e e ai a e
E o i es e o owi g ea u es i a y amic e i o me
• A We i e ace o egacy sys ems
• Au oma ica y ge e a e me a-i o ma io a y e me ia u c io a i y
• Su o o i ua ocume s i ua ocume s i E a e sou ce ocume s om a a y ica a ica io s e a ica io w a e as e a i i y o a se e eme s i e sou ce ocume s a y amica y ge e a es i ks ase o u e yi g e a io s i s owe e E oes o o i e ic y e me ia u c io a i y o e eme s a oes o su o y amic ege e a io e oca io a e-i e i ica io
• Ma i g u es o e ese a a ica io s i e a s uc u e Ma i g u es o i e a mec a ism o a comma s o a i k W e a use se ec s a i k om e is o i ks ge e a e i s ma i g u e e i es e comma s o a i k a e a ica io w a e wi se ose comma s o e a ica io o e ecu e
• W a e s o i eg a e a ica io s wi mi ima c a ges
e cu e E a c i ec u e co sis s o se e a we - e i e a se a a e
ocesses eac ossi y u i g o i e e a o ms I is s ow i igu e 5 1
igu e . E a c i ec u e
5 3 Com o e u c io a i y
Com o e u c io a i y is esc i e as o ows
• Use I e ace (UI is usua y u s o e use s com u e (We owse
• Use I e ace W a e (UIW : is se es ee im o a u c io s i s i a s a es e is aya e o io o e i e a messages om E s s a a o ma o a o ma e UI ca ocess a ice e sa; seco i a es e 83
commu ica io e wee e UIW a e UI; a i i im eme s a y u c io a i y e E equi es o e UI w ic e UI ca o o i e i se
• Gateway (GW is e a es e commu ica io amo g e E mo u es a wo ks as e ou e o a e E i e a messages A E messages ass oug e GW w ic e e i ec s em o e a o ia e mo u e
• Bridge Law Element Wrapper (BLEM): is ma s e a ica io a a a e a io s i s o y e e o ec s a u - ime i ge aws a e a o e ame o ma i g u es ( ie e 199 EM ma s e e eme i s a ces i e i ua ocume o e g o a e eme y es a i s e i ks o em
• Dynamically Mapped Information System (DMIS): is is a a ica io sys em a y amica y ge e a es e a a eques e y e use
• Dynamically Mapped Information System Wrapper (DMISW): is ma ages e commu ica io e wee e MIS a e a ica io sys em a s a es e use eques s om e E i e a o ma o e a ica io A I ecei es e ou u om e MIS a co e s i o e E o ma e MISW a so i e i ies a ma ks e e eme s wi i e MIS ou u o w ic y e me ia com o e s a e ma e
5.3 The Just-in-time Hypermedia Engine (JHE)
W i e E y amica y ge e a es i k a c o s a i ks o i ua ocume s i cu e y oes o su o e-i e i ica io e oca io o ege e a io e " us -i -
ime y e me ia E gi e" ( E is a e e sio o E I ca su eme a a y ica a ica io s wi y e me ia u c io a i y i is " us -i - ime" e i o me E s a c i ec u e is s ow i igu e 5 e o owi g sec io s esc i e i e i ie s e a c i ec u a com o e s a e i o ma io ow wi i E 84
5.3.1 JHE Architecture
e E a c i ec u e is s ow i igu e 5
igu e 5 E a c i ec u e 85
5 3 Component Functionality
E s a c i ec u e om igu e 5 uses ma y o e same com o e mo u es as E
U e i e com o e s a e e i e y ew o E a su o e-i e i ica io e oca io a y amic ege e a io
User Interface (UI): is usua y u s o e use s com u e (e g a We owse o i i g a We i e ace o e u e yi g a a y ica sys em E is ays i ua ocume s a c o ma ke s a is s o comme s a i ks o e UI
Document Translator (DT): is a s a es a age i E s i e a M o ma o a M age o is ay i equi e acco i g o e s y es ee em a e i e ow i ua ocume s is ay a ies o i e e We owse s Some We owse s ee s y es ee em a es o y; o e s may o y e a e o is ay M ages I e a e case a ocume a s a o is ee e
StyleSheet Templates: A s y es ee em a e is su ie o a i ua ocume o a se o i ua ocume s o is ay o e We owse
Selection Manager (SM W e e use se ec s a s a o co e o e UI i o e o c ea e a a c o e SM ge s e se ec io a ge e a es e a c o oca io i o ma io
Hypermedia Service Module (HSM): is ecei es e y e me ia co s uc i o ma io om e use e s o es y e me ia co s uc i o ma io i o e a a ase W e use isi s e y e me ia co s uc SM e ie es y e me ia co s uc i o ma io i o e a a ase a se s ack o e use
User Interface Wrapper (UIW): is se es ee im o a u c io s i s i a s a es e is aya e o io o e i e a messages om e E s s a a o ma o a o ma e UI ca ocess a ice e sa; seco i a es e commu ica io e wee e UIW a e UI; a i i im eme s e y e me ia u c io a i y o a ow use s a y e me ia co s uc s (comme s i ks ookma ks
Application: A com u e a ica io e e a o e y e me ia sys em is esea c ocuses o a a y ica a ica io s a y amica y ge e a e i ua ocume s as e esu o use que ies ese may e a y ki o use eques s o o y a a ase que ies
Application Wrapper (AW is ma ages e commu ica io e wee E a e a ica io sys em a s a es e use eques s om e E i e a o ma i o e o oco s e a ica io equi es a ecei es ocume s a sc ee s o is ay om e a ica io a co e s eac o a M ocume a em e s i i a i e a E message 86
Document Schema Database (DSS): A ica io s eci ic me a a a o i ua ocume s a i ua e eme s a e ge e a e a mai ai e y e A ica io W a e a s o e i o e ocume Sc ema a a ase
Regeneration Engine (RE): is se es ee im o a u c io s i s e E ge s e ecessa y comma s a a ame e s om e E a a ase acco i g o e i ua ocume I Seco o ege e a e ocume s i se s comma s o e a o ia e AW o e ecu io a ge s ack esu i g i ua ocume s om e AW i M age o ma i i com a es e ew y-ge e a e i ua ocume wi e is o y i o ma io s o e i E a a ase o e a i a e i
Document Manager (DM): is ooks o e y e me ia com o e s ( i ks comme s e c associa e wi a e-ge e a e i ua ocume a i ua e eme s wi i i ma ks e e-e is i g a c o s as e eme s a ge e a es a a e o e y e me ia com o e s o e i ua ocume e oca es a e-i e i ies e i ua e eme s o eci e i ey a e e same as e ious y ma ke o es
Virtual Document Identifier Manager (VDIM): is ge e a es a mai ai s a a e o i e i ie s o i ua ocume s i ua e eme s a y e me ia com o e s (suc as a c o s i ks a comme s
Ga eway (GW is e a es e commu ica io e wee e E mo u es a wo ks as e ou e o E i e a messages
5.3.3 Information Flow
I o ma io ows oug e a c i ec u e a e s ow as owc a s i igu e 5 3 a
igu e 5 igu e 5 3 s ows ow o isi a i ua ocume igu e 5 s ows ow o a o is ay a y e me ia co s uc e ai s a e esc i e as o ows
5.3.3.1 Visit a Virtual Document. e e a e wo ways o isi a i ua
ocume ei e y c ea i g a ew ocume o e isi i g a ookma k I e i s case
e use s ou e e a ame e s o e a ica io s ome age (w ic is a ea y i eg a e i o E a e su mi s i o UIW I e a e case e c ooses e
ookma k om e ookma k is is aye o e UI me u a su mi s i o UIW UIW ge s e use comma s om e UI a s a es e ecessa y i o ma io i o a i e a
E message a asses is message o e Ga eway e Ga eway o wa s i o e 87
AW w ic asses e comma s o i s a ica io o e ecu io e a ica io
e o ms e eques a se s e esu i g sc ee o ocume o e AW o is ay
W e e AW ecei es e esu i g ocume i a s a es e sou ce ocume i o a M ocume I i is a ege e a e ocume e ege e a io E gi e
e a i a es e ocume y a yi g e c i e ia i o ma io eco e i a a ase I i is a ew ocume (i e e e is o ookma k i o ma io a ou is ocume e
ocume Ma age ge e a es a u ique i e i ie o e i ua ocume a eco s e
i ua ocume i o ma io ( ocume i e i ie a ica io comma a ame e s e c i o a a ase e e ocume Ma age ooks o e y e me ia o ec s associa e wi is i ua ocume om e a a ase e ocume Ma age a so
e oca es a e-i e i ies i ua e eme s i is i ua ocume s e is i ua ocume is se ack o e owse o is ay
e ai s a ou ege e a i g i ua ocume s e oca io a e-i e i ica io wi
e esc i e i C a e o a ew i ua ocume i s i ee s o o e oca io a
e-i e i ica io ecause "g o a " a c o s a e a i o a ocume s ose y e me ia o ec s a a e "g o a " g a u a i y s ou e associa e wi e ew i ua ocume
A e e i ua ocume is ge e a e a is aye o e sc ee use s ca a
ew y e me ia co s uc s o is ocume Use s a so ca owse e y e me ia co s uc i o ma io o owi g e ai s ow o a o is ay a y e me ia co s uc igu e 5 s ows e i o ma io ow 88
5.3.3.2 Add and Display Hypermedia Constructs. W e a use a s a
y e me ia co s uc e c ooses a u c io ("a ookma k" "a comme " "a
i k" e c om e UI me u is o a a comme o a i k e ee s o se ec some
e s om e sc ee e Se ec io Ma age ge e a es a c o oca io i o ma io o
e se ec e e s e e use e e s o e a c o i o ma io suc as ame g a u a i y a e-i e i ica io c i e ia o e sc ee e UIW acks e comma s i o a message a se s em o Ga eway o a a ookma k e use oes o ee o se ec some e s om e sc ee e us e e s e ookma k i o ma io suc as ame a e a i a io c i e ia e UIW acks e comma s i o messages a se s em
o Ga eway Ga eway ecei es e message a ca s e y e me ia Se ice Mo u e
( SM o ocess e comma s o a ookma k SM s o es ookma k i o ma io i o a a ase o a a comme o a i k SM s o es e a c o i o ma io i o
a a ase a e i s o es comme o i k i o ma io i o a a ase A e a e i o ma io as ee s o e i o a a ase success u y Ga eway se s a message o
UIW i a y UIW e es es e ocume a i se s sig s a e si e o e ew y c ea e a c o s o UI o is ay
W e a ocume is ge e a e i is is aye wi a c o s Eac a c o as a sma ico i se e a i s si e W e e use c icks o e ico E o s a ew wi ow
o is ay a is o comme a i k i es o e sc ee is is ca e " is ay
y e me ia co s uc s" i igu e 5 I is case SM e ie es a comme a i k i o ma io o e a c o om a a ase W e e use c icks o e comme o a i k
i e o e sc ee SM e ie es e comme a i k i o ma io om a a ase o a comme UI is ays comme i e a co e o e sc ee o a i k i e i k 89
es i a io is a a c o o a ookma k Ga eway ca s AW a E o o ege e a io a UI is ays e es i a io i ua ocume I e i k es i a io is a U UI
is ays e age co e o e U
o a ookma k i is s ow i e UI me u W e E s a s u Ga eway
e ie es a ookma k i o ma io a a ookma k i es a e is e i e UI me u 0
igu e . Visit a document.
igu e 5 A a is ay y e me ia co s uc s CHAPTER 6
IMPLEMENTATION
is c a e esc i es e E im eme a io e ai s Sec io 1 esc i es e a ica io i eg a e i e E sys em i c u i g e a a ysis o e a ica io mo u e a i s ou u Sec io esc i es im eme a io e ai s o eac mo u e i e E a c i ec u e
6.1 Application
Cu e y ASA s SS C ( a io a S ace Scie ce a a Ce e We sys em is use as
e es e e SS C sys em o i es s ace scie ce a a a ma y scie i ic mo e s
o ca cu a e a esc i e s ace a a Sec io 1 1 esc i es e SS C sys em Sec io
1 i o uces e ea s mag e ic i e mo e s Sec io 1 3 gi es esc i io o e
9 mo e as a e am e o e mag e ic ie mo e s I a so iscusses e i u
a ame e s a ou u ocume s o e 9 mo e e 9 a ica io o uces ca cu a io esu s ase o use i u a ame e s e ocume s a e ge e a e
y amica y w ic a ie y i e e i u a ame e s is is a goo es mo u e o
E
6.1.1 NSSDC
e a io a S ace Scie ce a a Ce e se es as e e ma e a c i e o ASA s ace scie ce missio a a "S ace scie ce" mea s as o omy a as o ysics so a a s ace asma ysics a a e a y a u a scie ce As e ma e a c i e SS C
92
eams wi ASA s isci i e-s eci ic s ace scie ce "ac i e a c i es" w ic o i e access o a a o esea c e s a i some cases o e ge e a u ic
SS C o i es o i e i o ma io ases a ou ASA a o - ASA a a as we as s acec a a e e ime s a ge e a e ASA s ace scie ce a a SS C a so
o i es i o ma io a su o e a i e o a a ma ageme s a a s a
ec o ogies e we si e is // ss c gs c asa go /
6. .2 Mag e os e e ie Mo e s
e Ea s mag e os e e is a e y y amic sys em I s co igu a io e e s o i e a a e e a ac o s e i s ac o is e o ie a io o e Ea s mag e ic a is wi es ec o e Su -Ea i e w ic a ies wi ime ecause o o e Ea s
iu a o a io a i s yea y o i a mo io a ou e Su A o e im o a ac o is
e s a e o e so a wi i a icu a e o ie a io a s e g o e i e a e a y mag e ic ie "ca ie " o e Ea s o i om Su owi g o e ig e ec ica co uc i i y o e so a wi asma
Mo e i g o e g o a geomag e ic ie as a u ique ace i e Su -Ea co ec io s u ies si ce a ie u e ies a ocesses i e ea -Ea s ace e i o me
• I i ks e i e a e a y me ium wi e u e a mos e e a io os e e;
• Gui es e e ge ic c a ge a ic es;
• C a e s ow- eque cy e ec omag e ic wa es;
• Co i es e a ia io e s a co o s e au o a asma;
• i ec s e ec ic cu e s; 4
• S o es uge amou s o e e gy i e mi e y issi a e i e cou se o mag e os e ic su s o ms
Mag e ic ie s e e mi e key o e ies o e geos ace asma i a icu a i s a iso o y w ic makes i ossi e o com a e o se a io s ma e i i e e egio s o s ace y ma i g em a o g e mag e ic ie i es
e e a e ma y mag e ic ie ca cu a io mo e s suc as Τ9 mo e
IG / G mo e a IGS mo e Sec io 1 3 esc i es Τ9 mo e w ic is i eg a e i e E sys em as a es a ica io
6. . 6 Mo e
e 9 mo e co e ca cu a es i o e a Co ec e GeoMag e ic (CGM coo i a es a se e a o e geomag e ic ie a ame e s o geog a ica y s eci ie oi s a e
Ea s su ace ( 371 km o i ea -Ea s ace
igu e 1 s ows e ome age ( // ss c gs c asa go /s ace/cgm/ 9 m1 o e Τ9 mo e I as a que y a e w ic a ows use s o e e a ame e s a e gi es ou e ca cu a io esu igu e 1 s ows e equi e i u a ame e s esc i e as o ows
• Yea e wee 19 5 a 5 (i o e yea i c eme s ;
• ay o e yea ( om 1 o 3 ou mi u e a seco i U ;
• Geoce ic a i u e a o gi u e o a gi e oi ;
• A i u e o e oi a o e e Ea s su ace ( km is a u e imi ;
• So a wi a ame e s e si y ( /cm 3 e oci y (km/sec IM y ( a ( com o e s i e GSM coo i a es a e s -i e
igu e 6. Τ9 mo e que y a e
igu e s ows a e am e o ca cu a io esu e ou u as wo a s i u
a ame e s a com u e ou u a ame e s o a gi e oi e ou u a ame e s a e
• i o e a CGM coo i a es;
• G /IG mag e ic ie com o e a ues ( ( eg ( Y ( a (πΤ ;
• E e a sou ces geomag e ic ie com o e a ues ( Y ( a ( a e gi e oi ;
• A e o e mag e ic ie i e a co es o i g -mi ie a ue w ic esu e om e i e a a e e a sou ces;
• Geoce ic coo i a es o e -mi oi a ia y o ec e o e Ea s su ace; 96
• Geoce ic coo i a es o e ea is ic mag e ica y co uga e oi a i s i o e a CGM coo i a es as we as e i e a a e e a geomag e ic ie com o e a ues a is oi
igu e Ca cu a io esu
e sou ce ocume is a M i e W e a use e e s i i e e
a ame e s e ca cu a io esu s a e i e e owe e i simi a o ma igu e 3 s ows a o e ca cu a io esu I s ows a ma y e eme s a e i e e a ues suc as "mo " " ay" "mi u e" e c e a so u e oca io o eac e eme as c a ge
om e o igi a o e I is case eco i g y e o se o eac e eme is o a goo way o eco a a c o
igu e 6. A o e e am e o Τ9 mo e ca cu a io esu
W e a use e e s some a ame e s i o e Τ9 a e a c ick "su mi que y"
e SS C se e wi ge e que y a ame e s a ca cu a e e Τ9 mag e ic ie mo e e se s i o e owse e su ose e use ookma ks e ca cu a io
esu e e ime e use e isi s e ookma k i s ou gi e e ookma ke esu
o e use owe e e We owse gi es ou e e o message s ow i igu e
U ike ma y we si es w ose que y a ame e s a e a e a e e U is Τ9 mo e we si e i es que y a ame e s i ackg ou eques s I is case ge e a ookma ks y cu e We owse s ca o o y amic ege e a io 8
igu e 6.4 9 e o
Im eme a io e ai s is sec io esc i es im eme a io e ai s o mo u es E is a We se e a ca i eg a e ma y e e a a ica io s a su y y e me ia u c io a i y o em E uses A ac e omca We se e ( // aka a a ac e o g/ omca / a a a a guage o
o og ammi g Mos E mo u es a e og amme i a a o u oge e wi e
A ac e ackage E uses a aSc i a guage o og am o use i e ace esig w ic is a o e Use I e ace Mo u e e Se ec io Ma age a so uses some
a aSc i u c io s o ge se ec io s om wi ow
e A ica io W a e (AW y e me ia Se ice Mo u e ( SM a e
ege e a io E gi e ( E ea wi ege e a io e AW i e ce s e a ica io
ocume a a ses e ocume i o a M ocume Sec io esc i es e
AW e SM s o es a e ie es ookma k i o ma io Sec io 3 esc i es e
SM e E e a i a es e ocume Sec io 5 esc i es e E
e ocume Ma age ( M a e Se ec io Ma ge (SM ea wi
e oca io a e-i e i ica io e SM ge e a es a c o i o ma io Sec io
esc i es e SM e M i s a a c o s e a e o a i ua ocume a i e e ac osi io s o e a c o s a e-i e i y e a c o co e Sec io 7 esc i es
e M
e Use I e ace W a e (UIW co ai s se e a Use I e ace (UI me us o a ow use s o a ookma ks comme s a i ks o a i ua ocume e SM s o es a e ie es ookma k comme a i k i o ma io i o a a ase Sec io 7
esc i es e UIW
U ique i e i ie s a e c ucia o i ua ocume s a c o s comme s a
i ks Sec io 1 esc i es i e i ie s E as a a a ase sys em o s o e a a a a i o ma io o i ua ocume s a y e me ia co s uc s Sec io esc i es e
E a a ase sys em a a a ase esc i io s o y e me ia co s uc s
6.2. I e i ie s
e u ique i e i ie s i e E sys em i c u e ocume a c o a y e me ia o ec i e i ie s ey a e u ique um e s ge e a e y e E sys em e ge e a io a go i m uses e sys em ime s am I a a a guage e comma is
o g i = Sys em cu e imeMi is( ;
e i ua ocume i e i ie is e a so u e a ue o e sys em ime s am
e a c o i e i ie is a a e "A" us e sys em ime s am o owi g s ows some i e i ie s e am es
ocume i e i ie 11 117 37 5 A c o i e i ie A 1 117 Comme i e i ie C 11 15 93 171 00
Link identifier: Li 101176948060
All identifiers are generated by the Identifier Generator Module and stored in a database.
6.2.2 E a a ase
The JHE database stores information about virtual document, bookmark, comment, link and application commands. The Java language has the JDBC interface for the developers to store and retrieve information in database. The JDBC interface needs a bridge driver and a data warehouse depending on different operating systems. The bridge driver is a middleware between the native database driver and the JDBC driver. A data warehouse is an application that allows users to create table and store records in some database file.
For example, in the Microsoft Windows system, the native database driver is ODBC, the data warehouse could be Access, Excel, dBase or Visual Fox Pro. Currently JHE is running on Windows XP and it is using the Access database system. The data is stored in some .mdb file. The ODBC driver can use the Access database system, but JDBC can not use the Access database system directly, thus an ODBC/JDBC bridge driver needs to be installed. JHE uses the RmiJDBC (http://rmijdbc.objectweb.org) bridge driver.
Implementing the JHE database module has following steps:
(1) Download the RmiJDBC driver from: http://rmijdbc.objectweb.org/download.html.
(2) Compile the source codes and install the RmiJDBC driver.
(3) Use the Access application to create an empty Access database file called jhe.mdb.
(4) Setup the ODBC datasource to use jhe.mdb according to the following web page: http://rmijdbc.objectweb.org/Access/access.html. 0
(5 Use e Access a ica io o c ea e o mo i y a a ase a es E as "A c o " " ookma k" "Comme " " i k" a o e a es
( C ea e a E a a ase a a c ass o use e C i e ace is a a c ass ca use e C i e i e ace o s o e a e ie e i o ma io i o e a a ase I uses e SQ (S a a Que y a guage o s o e a e ie e a a
6.2. y e me ia Se ice Mo u e ( SM
e SM is a a a c ass a s o es a e ie es y e me ia co s uc i o ma io i o
e E a a ase e e a e ee y e me ia u c io a i y me us is aye o e UI
ey a e e ookma k Me u Comme Me u a i k Me u ese Me us a e a s o e UIW ey a e M ages a a ow use s o e e a ame e s a su mi e i o ma io o e Ga eway e Ga eway o wa s e y e me ia u c io a i y comma a a ame e s o e SM SM a ses e comma a s o es e
y e me ia co s uc i o ma io i o e E a a ase W e e use c icks e
y e me ia co s uc ico s o e sc ee e SM ecei es e y e me ia u c io a i y comma a a ame e s om e Ga eway e SM e ie es e y e me ia co s uc i o ma io om e E a a ase a e se s i o e Ga eway e UIW
ecei es e i o ma io om Ga eway a is ays e i o ma io o e UI Sec io
3 1 esc i es e ookma k comme a i k e i i io s i e a a ase a gi es e am e eco s i e a a ase Sec io 3 e ai s ow o s o e a e ie e e
y e me ia co s uc i o ma io om a a ase
6.2. . y e me ia Co s uc I o ma io i e E a a ase. E su o s a c o ookma k comme a i k 02
• A c o I o ma io
e e is e a a ase a e o e a c o A c o = (A c o I , Que y ocI , oca io , G a u a i y, Se ec io , C i e ia "A c o I " is e u ique i e i ie o is a c o "Que y ocI " is e i ua ocume i e i ie o e ocume co ai i g e a c o " oca io " is e oi e e essio o e a c o "G a u a i y" is e a c o s sco e i e sys em w ic as ee o io a a ues g o a oca a s eci ic See e ai e a a io s i Sec io 3 3 "Se ec io " is e se ec e e om e sc ee "C i e ia" is e e-i e i ica io u e o e a c o See e ai i Sec io 3 3
o owi g is a e am e o a c o i o ma io ( A1 3795 53 1 379 959 99 oi e (s a - oi (s i g a ge( / m [ 1 ]/ o y[ 1 ]/ca cu a io esu [ 1 ]/i u a ams [ 1 ]/mi u e[ 1 ]/ ame[ 1], " 1 1 / a ge- o(e - oi (s i g- a ge( / m [ 1 ]/ o y[ 1 ]/ca cu a io esu [ 1 ]/i u a ams[ 1 ]/mi u e[ 1 ]/ a ue[ 1 ] " 1 1 G o a Mi = 9 c a ge ;
• ookma k I o ma io
o owi g is e a a ase esc i io o ookma k a o e e am e o e eco ookma k = (Que y ocI , ame, C i e ia, Co e ( 1 773 a e a e u "Que y ocI " is e u ique i e i ie o e i ua ocume w ic is a so e i e i ie o e ookma k i s "1 773 " i e a o e e am e " ame" is e use ec a e ookma k ame i s "a e a e " i e a o e e am e "C i e ia" is e e a i a io c i e ia see e ai s i Sec io 3 3 e a ue is " " i e a o e e am e w ic i ica es a e a e que y a acce a e o ege e a io "Co e " is e eco e ocume co e o e a i a io u ose e a ue is " u " i e a o e e am e
• Comme I o ma io
o owi g is e a a ase esc i io o comme a o e e am e o e eco Comme = (comme I , A c o I , ame, Co e "comme I " is e u ique i e i ie o a comme "A c o I " is e u ique i e i ie o e se ec e a c o " ame" is e use ec a e comme i e "Co e " is e comme co e
o owi g is a e am e o e comme i o ma io ( C1 379 113173 A1 379 1 131 yea is is yea ; 103
• i k I o ma io
o owi g is e esc i io o a i k a e i e a a ase a a e am e o i k i o ma io Link = (linkID, Name, Type, srcAnchorID, dstAnchorID); "linkID" is e u ique i e i ie o a i k "Name" is e use gi e i k ame "Type" s eci ies e es i a io y es a c o ookma k U "srcAnchorID" is e u ique i e i ie o e sou ce a c o "dstAnchorID" is e u ique i e i ie o e es i a io I e es i a io is a a c o e i s a a c o I ; i e es i a io is a i ua ocume e i s a ocume I ; i e es i a io is a e e a U e i s a U
o owi g s ows some e am es o i k i o ma io 11 591 71 9 es i k a c o A11 591 71 5 A11 591 1913 ( 11 599 7 7 1 i ua oc i k ookma k A11 599 7 7359 11 5919 3 ( 11 5999515 71 e e a i k U A11 5999515 5 www asa go
e i s e am e s ows e es i a io is a a c o i a ocume us e es i a io y e is "a c o " e es i a io I is a a c o I e seco e am e s ows e es i a io is a i ua ocume si ce e es i a io y e is " ookma k" e e o e e es i a io I is a i ua ocume I e i e am e s ows e es i a io is a e e a U us e es i a io y e is "U " e es i a io I is a U
6.2.3.2 Store and Retrieve the Hypermedia Construct Information. SM ecei es messages om e Ga eway a e a ses e comma a a ame e s i e eques
I E e message is a a a a am a e c ass w ic s o es ai s o key a a ues i e
a am a e a a s uc u e igu e 5 s ows e sou ce co es o a se a ocess a
y e me ia u c io a i y eques om UIW o e am e UIW se s a eques o a a
i k e a am a e co ai s e key "a i k" e key " i kI " wi e a ue o e
i k i e i ie a c o i o ma io a a so o e i k i o ma io s o e as key a ue
ai s SM ca s e u c io a i k o( a e I e u c io a i k o( a e
SM ge s a c o a i k i o ma io om a e e ca s e a a c ass
E a a ase o i se a c o a i k i o ma io i o a a ase 04
a am a e a e = eques ge a am a e( ;
i ( a e co ai sKey("a Comme "
{ a Comme o( a e ;
} e se i ( a e co ai sKey("a i k"
{ a i k o( a e ;
} e se i ( a e co ai sKey("a ookma k"
{ a ookma k o( a e ;
} e se i ( a e co ai sKey(" y e Co s uc "
{ o ec I = a e ge a amAsS i g(" y e Co s uc " ; y e Si e = ge y e Co s uc s(o ec ;
} e se i ( a e co ai sKey("comme "
{ comme = a e ge a amAsS i g("comme " ; A ay is comme o = ew A ay is ( ; ge Comme o(comme comme o ;
} e se i ( a e co ai sKey(" i k"
{ i k I = a e ge a amAsS i g(" i k" ; A ay is i k o = ew A ay is ( ; ge i k o( i k i k o ;
}
igu e 6. S o e o e ie e y e me ia co s uc i o ma io
6.2.4 A ica io W a e Mo u e
e A ica io W a e (AW is a a a c ass a i e ce s e a ica io comma s a ca c es e sou ce ocume s om a ica io s e i a ses e sou ce ocume a a s a es i i o a we -s uc u e M ocume e AW e o ms o owi g s e s 105
(a) Catch the underlying parameters
e a ica io s comma a a ame e s a e a a y e I mos cases i ca e i e e
om e que y a e a e We si e su ies Usua y e M " o m" e i y as e i o ma io a ou e a ame e s a e a ica io comma s o e am e i e 9 mo e que y a e ( igu e 1 e M i e as a " o m" s ow i igu e e
M ocume i igu e s ows e a ica io es i a io is http://lewes.gsfc.nasa.gov, e comma is "cgi- i /mo e s/ 9 _m" e e is a is o
a ame e s ee s o e i e i suc as "yea " " ay" a "a i u e" Use s ca e e
a ame e s i o e e o es o e sc ee e c icks "su mi " u o o e sc ee
e We owse wi se e comma "cgi- i /mo e s/ 9 _m" a a ame e s
("yea " " ay" "a i u e" e c o e es i a io "http://lewes.gsfc.nasa.gov".
E i e ce s e eques y e aci g e a ica io es i a io wi E s mo u e ame a e comma wi E s comma igu e 7 s ows e i e ce e que y o m e e e es i a io a ica io i e i s i e is c a ge o " e" a e comma o "sc" u a ame e s a e same as e o igi a o es e e eques wi go
oug e E Ga eway 06
igu e 6.6 Original HTML "form". 0
igu e 6. Intercepted HTML "form". 08
( Ca e a ica io o e ecu e
W e a use c icks e u o e UIW wi se e comma "/ e/sc" oge e wi
e a ame e s o e E Ga eway i s e e Ga eway o wa s i o e es i a io
A ica io W a e (AW e AW a ses e que y esu ma s e E es i a io a comma o e ea a ica io es i a io a comma o e am e " e" ma s
o "http://lewes.gsfc.nasa.gov", "sc" ma s o "cgi- i /mo e s/ 9 _m" e e AW se s a eques o e es i a io a ica io wi a ame e s ( e ea U o
e a ica io e ea a ica io ( e " ewes g c asa go " We se e e ecu es
e comma ( e CGI comma o e We se e a a ame e s ( e o g a ame e
is e e ea a ica io se s ack e ocume o e AW
(c a se e sou ce ocume
e AW a ses sou ce ocume acco i g o e ocume s uc u e e a s a es e e eme s i o M e eme s a o ms a M ocume is is i e e o eac a ica io Eac a ica io as a ocume em a e o e am e i e sou ce
ocume s s ow i igu e a igu e 3 ey a e a commo ocume s uc u e
us a e i e e e eme a ues a si g is ocume is o i icu o e am e o e eme "yea = " i ca e a s a e as a e eme "YEA " i s ame is "yea "
a ue is " " e " AY" e eme i igu e as a a ue o "1" w i e i igu e 3 i s a ue is "1 "
( a s a e e a se ocume i o a M ocume
A e e AW a ses e sou ce ocume a ge s e eme s a ues e ocume is
es uc u e a a s a e i o a M ocume ase o e ocume s uc u e
W i e e cu e i s a ia io o a ocume is a se au oma ica y usua y e 0
ocume s uc u e is a a y e ma ua y i a a ce e ocume s uc u e is esc i e as a M Sc ema igu e s ows e ocume sc ema o 9 mo e
igu e 6.8 A ocume sc ema o 9 mo e
6.2. ege e a io E gi e ( E
e ege e a io E gi e is a a a c ass a e o ms e o owi g s e s o ege e a e a
i ua ocume
(1 Ge que y comma a a ame e s om a a ase y e u ique ocume i e i ie ;
( Se a eques o e AW a e ge ocume ack;
(3 a i a e e i ua ocume y i e e c i e ia
E ecei es e sou ce ocume e e a i a es o i e e c i e ia 0
C i e ia E ac co y is mea s i ee s o o y e com a iso e wee e ew ocume a e s o e ocume
C i e ia 1 a ues ca c a ge is mea s i ee s o com a e e ocume s uc u e
C i e ia A e a e que ies is mea s o o ee o com a e wi is o y i o ma io
W e e use c ea es a ookma k i e "C i e ia" is " " e e ocume wi
e s o e i e E se e e "co e " a ue i e ookma k eco is e i e ame
e i e is s o e i e same i ec o y a e E se e oca es I igu e 9 e
a ia e " ocume " i e u c io is e ege e a e ocume I e "C i e ia" is " "
E ca s e u c io com a e oc I e u c io "com a e oc" i e ie es e i e
ame om a a ase a ea s e o igi a ocume om e s eci ic i ec o y a s o es ocume s e i com a es e o igi a ocume wi e ew ocume y e
y y e
I e "C i e ia" is "1" E ca s e u c io " a se oc" I e u c io
" a se oc" E ca s e AW o a ses e ege e a e ocume acco i g o a s o e
ocume em a e o e am e i e 9 ca cu a io esu e wo "yea = 5" i ica es is is a "yea " e eme w ic as e a ue " 5" is ocume o ows a s eci ic ocume em a e w ic e i es e ames a o e s o e keywo s a
ei a ues o e am e e " ay" keywo o ows e "yea " keywo wi some
a ues e o e is im o a i i c a ges is mea s e ocume s uc u e c a ges
e a si g ocess wi ai I e "C i e ia" is " " e E oes o com a e a y i g
u ic oo ea a i a e oc( ocume ocume S i g Que y ocI S i g c i e ia
{ i (c i e ia equa sIg o eCase(" " // e ac y same
{ e u (com a e oc( ocume Que y ocI ;
} e se i (c i e ia equa sIg o eCase(" 1" II a ue ca c a ge
{ e u ( a se oc( ocume Que y ocI ;
} e se // o o com a e a y i g
{ e u ue;
} e u ue;
igu e 6. e a i a io oce u e
I e a i a io is success u e e ocume Ma age wi o e oca io a
e-i e i ica io o a e a e a c o s o e i ua ocume s o e wise i wi gi e wa i g messages o use s
6.2.6 Se ec io Ma age
W e a use se ec s some e s om sc ee e c icks a u o e Se ec io Ma age wi ge e a e a oi e e essio a e se s i o e Ga eway e Se ec io
Ma age is o a a a c ass esi es E use s ee o i s a e Mo i a
(http://mozilla.org) owse a a ce i ica e i o e o use e Se ec io Ma age e im eme a io as o owi g s e s
(a E a e oi e i se ice
e Se ec io Ma age is im eme e y Mo i a s oi e i
(http://xpointerlib.mozdev.org/). oi e i is o e o Mo i a s COM
(http://www.mozilla.org/projects/xpcom/) i a ies oi e i ge e a es oi e e essio s w e use s se ec some e s om e sc ee o e a e oi e i s 2 se ice e E e e o e ee s o ow oa a i s a e oi e i ackage i s
e i s a a io as o owi g s e s
(1 O e Mo i a we owse
( Go o http://xpointerlib.mozdev.org/installation.htrnl.
(3 C ick "i s a a io " u o o e a o e we age
( I s a e Com iewe om http://www.hacksrus.com/-ginda/cview/.
(5 C ick Mo i a s me u " oo s" - "We e e o me " - "Com o e iewe "
( I e oi e i se ice is s ow i e e co um o e iewe e e oi e i is i s a e co ec y igu e 1 s ows e Com Com o e iewe
igu e 6. 0 Com com o e iewe 113
(b) Add a function to get XPointer expression from the desired HTML page
e e E e e o e a s e o owi g a asc i u c io o a M i e w e e
E wa s o se ec some e s a ge s oi e e essio s
u c io ge (
{ e sca e secu i y i i egeMa age e a e i i ege("U i e sa Co ec " ; a Se ice = Com o e s c asses[" mo i a o g/ oi e -se ice; "] ge Se iceO; Se ice = Se ice Que y e ace(Com o e s i e aces sI oi e Se ice ; a S i g = Se ice c ea e oi e omSe ec io (wi ow _co e ge Se ec io ( wi ow _co e ocume ; e u S i g;
}
e UIW au oma ica y a s e a o e a asc i u c io o e e y ocume
is aye o e sc ee
(c) Install the Mozilla certificate
E use s s ou i s a a Mo i a ce i ica e o e Mo i a owse E use s ca o use o e We owse s suc as I e e E o e o Sa a i o access E ecause E uses Mo i a s oi e i se ice w ic is o a ai a e i o e owse s e ce i ica e is a au o i y i e om e We se e o a ow use s o use some u c io s
a i su o s e E e e o e o e We a mi is a o c ea es a ce i ica e e
E use s i s a i o ei ow com u e s w ic a e e Mo i a owse is ce i ica e is o a o e E mo u e us i s o a a a c ass o some a asc i
u c io s I is a i e a co ai s igi a sig a u es a e c io i o ma io
C ea i g a ce i ica e as o owi g s e s
(1 ow oa a i s a SS ( e sca e Secu i y Se ice 3 7 om http://ftp2.de.freebsd.org/pub/misc2/mozilla/security/nss/releases/NSS 3 7 8 R M 114
( C ea e a is i u e a ce i ica e see http://books.mozdev.org/html mozilla-chp- 12-sect-5.html o e ai s Ac ua y e e a e wo ce i ica es e oo ce i ica e a e is i u e ce i ica e e E a mi is a o c ea es ese wo ce i ica es e i s a s e oo ce i ica e o e E se e e a so se s e is i u e ce i ica e o E use s e e e y E use i s a s e is i u e ce i ica e o is Mo i a owse
(3) If a use o e a mi is a o wa s o c eck w e e e Mo i a owse as e ce i ica e om JHE, e o e s e Mo i a owse a se ec s Mo i a owse s me u "E i " - " e e e ces" - " i acy Secu i y" - "Ce i ica es" c icks "Ma age Ce i ica e" e e "Ce i ica e Ma age " wi ow s ows a ew ce i ica e is i s a e igu e 11 s ows e E Mo i a ce i ica e ( e ig ig e i e is i s a e ow e JHE e gi e ca use e oi e i se ice
(d) Send XPointer expressions to JHE gateway
is is o e y usi g M s o m ca a i i y W e a use c icks e "su mi " u o
e owse wi se a HTTP "POST" eques oge e wi some a ame e s (suc as se ec e e co e oca io e essio s a e i ua ocume ID) o e es i a io mo u e — e Ga eway
Figure 6.11 Mo i a ce i ica e ma age 115
6.2.7 Document Manager
e ocume Ma age is a a a c ass a ge s a e a e a c o s om e E
a a ase e e oca es a e-i e i ies a c o s acco i g o i e e c i e ia e
ocume Ma age e o ms e o owi g s e s (see igu e 1
(1 Ge a a c o is om a a ase is i c u es a g o a a c o s a o e oca o s eci ic a c o s a as e same ocume i e i ie wi is i ua ocume
( E a ua e eac o ese a c o s acco i g o e c i e ia i s e ocume Ma age i s e a c o oca io acco i g o ocume s uc u e e i com a es e e eme a ue wi e is o y i o ma io i e c i e io oes o a ow e eme a ue o c a ge; i oes o com a e e e eme a ue i e c i e io a ows e eme a ue o c a ge e ocume Ma age uses A ac e s a oo (w ic is a a a c ass ackage a e a ua es a e essio s i a OM ocume o i e a c o oca io s e ig ig e co es i igu e 13 s ow ow e oi e e essio is e a ua e a e e eme a ue is e ie e om e ocume e e u c io com a es e o igi a a ue wi e ew a ue
(3 e ocume Ma age i s a e a e y e me ia co s uc s o eac a c o (comme i ks e c e i a ac y e me ia o ec s o is ocume y n t nσ i c t thρ f . o ». ι m me
Figure 6.12 owc a o a c o e oca io a e-i e i ica io 116
}
Figure 6.13 E a ua e a oi e e essio
6.2.8 User Interface Module (UIW)
A e a use ogge i E i wi ake im o e use i e ace (s ow as igu e 1
e use i e ace is com ose o ou a s a ica io is mai wi ow me u is a me u wi ow e u e e sc ee s ows e a ica io is a E su o s
Cu e y E o y su o s e SS C a ica io u wi su o mo e a ica io s i e u u e e u e ig sc ee s ows e i ua ocume om a ica io s e
owe e sc ee s ows e y e me ia u c io a i y a E su o s is i c u e
ookma k is a ew ookma k a ew comme a a ew i k me u e owe
ig sc ee s ows e me u co e w ic a ows use s o e e some i o ma io o se ec some i o ma io om me u e e is o me u co e i igu e 1 ecause e use oes o se ec a y me u a e e oges i E igu e 15 s ows e ookma k
Se ice Me u co e a e owe ig co e o e wi ow e UIW co ai s
ookma k Se ice Me u i k Se ice Me u a Comme Se ice Me u Eac se ice me u is a M age co ai i g some i u a ame e s a a aSc i u c io s
igu e 6. 4 E mai me u
• ookma k Se ice Me u
W e a use wa s o a a ookma k e c icks e "a ookma k" u o o e sc ee e e ookma k se ice me u wi a ea a e ig co e o e wi ow s ow as igu e 15 e ookma k Se ice Me u is a M age wi some
a aSc i u c io s e M age as a " o m" o a ow use s o i u a ame e s
om sc ee suc as e ookma k ame a e a i a io c i e ia 8
i e E i iew Go ookma ks oo s W ow e :...... 4 : ηoca os :8080 e gi e ome Τi iρme Βα cma ke e Mo i a O ga ma a io 4 Ιa es ui s
Ci CC We come o e us i ime y e me ia E gi e
is is e ookma k is : o you wa o eco is esu ?
a ue c a ge Ci O y is esu e ac co y ? aίues ca c a ge A e a e esu s
i·-Su mi
A ookma k3 ame A Comme Γ k
E: :0
igu e 6. ookma k se ice me u
• i k Se ice Me u
W e a use wa s o a a i k e c icks e "a i k" u o o e sc ee e e
i k se ice me u wi a ea a e ig co e o e wi ow s ow as igu e 1
e i k Se ice Me u is a M age wi some a aSc i u c io s e M
age as a " o m" o a ow use s o i u a ame e s om sc ee suc as e i k ame a i k es i a io W e e use c icks e "su mi " u o UIW acks e i o ma io a se s i o Ga eway Α i k es i a io cou e a U e e e y e use a a c o o a ookma k W e UIW com oses e i k Se ice Me u i e ie es a a c o s a ookma ks a is s em i e me u I a use wa s o a a i k o a 119
ookma k o a a c o a as o e is e e s ou c ea e i i s a e makes a i k
o i
• Comment Service Menu
W e a use wa s o a a comme e c icks e "a comme " u o o e sc ee a e e comme se ice me u wi a ea a e ig co e o e wi ow s ow as igu e 17 e Comme Se ice Me u is a M age wi some a aSc i
u c io s e M age as a " o m" o a ow use s o i u a ame e s om sc ee suc as e comme ame a co e 20
igu e 6. Comme se ice me u
6.2. ocume a s a o
e ocume a s a o a s o ms e M ocume i o a is aya e M
o ma I E e M i e a so i c u es is aya e a s (sou ce ocume om a ica io a o - is aya e a s e o - is aya e a s i c u e sys em a a
(e g ocume i e i ie s a ookma k i o ma io is a sc i u c io s e sc i u c io s im eme some o use i e ace u c io s e ocume a s a o is a a a c ass u i g o e E se e 121
6.2.10 Tools Used In The JHE Project
The JHE project is a Web based project which uses the following tools:
(1) Java and Javascript: (http://java.sun.comf). Java is a platform independent language, which is widely used in Web applications. Java is usually programmed to run on server side. Javascript is a script language running on client side.
(2) JDOM.(http://www.jdom.org/docs/apidocs/) . JDOM is a Java API that can access, manipulate, and output XML data.
(3) Mozilla and related utilities (http://www.mozilla.org ). Mozilla is an omen source Internet client suite designed for standards compliance, speed and portability. Mozilla is not only a Web browser, but also provides much functionality for Web applications.
(4) Apache Tomcat Web server (http://jakarta.apache.org/tomcat/) . Apache Tomcat is an open source Web server, which supports Java Servlet (http://java.sun.com/products/servletlindexjsp) and Java ServerPage (http://java.sun.com/products/jsp/) technologies. The Java Servlet and JavaServer Pages specifications are developed by Sun under the Java Community Process (http://java.sun.com/aboutJava/communityprocess/). CHAPTER 7
RESULTS AND EVALUATIONS
is c a e gi es some es esu s a e oes e a ua io ase o e us -i - ime
y e me ia amewo k esc i e i C a e 3 Sec io 7 1 esc i es y amic
ege e a io esu s a e a ua io Sec io 7 esc i es y amic y e me ia
u c io a i y esu s a e a ua io Sec io 7 3 esc i es y amic e oca io a e- i e i ica io esu s a e a ua io Sec io 7 com a es E wi o e simi a sys ems Sec io 7 5 iscusses sys em e e si i i y i a y Sec io 7 esc i es WWW s a a s use i E
7.1 Dynamic Regeneration
E i eg a es a ica io mo u es i o e y e me ia sys em a e ge s e use comma s om UI I se s e use eques s o e es i a io a ica io o e ecu io a ecei es e sou ce ocume s W e a use e isi s a ookma k E wi e a i a e
e ge e a io esu s acco i g o i e e c i e ia Sec io 7 1 1 gi es some es esu s o y amic ege e a io Sec io 7 1 e a ua es e es esu s
7.1.1 JHE Regeneration Results
o ge a ege e a io esu e use c ea es a ookma k e e isi s i a e
7.1.1.1 Create a Bookmark. igu e 7 1 s ows e 9 a ica io mo u e is i eg a e i o E W e use se ec s e " 9 Mo e " comma (w ic is ea om
e sys em se i g i e w e E s a s u om e UI me u i gi es use s e 9
ome age w ic as e que y a e is a ows use s o e e i a ame e s e o e e
1 2 use c ea es a ew ookma k e ee s o e e a su mi a ame e s o E o c ea e a
ew ca cu a io esu A e e a s a ew ookma k o e esu e wi o ee o e e a ame e s agai e e ime E wi o ege e a io au oma ica y
igu e 7 s ows e ca cu a io esu a e e use e e s some a ame e s
W e e use se ec s e "a ookma k" comma om e me u a e ig co e o
e wi ow e ookma k Se ice Me u wi om e use o e e i ookma k i o ma io suc as ame ("e ac co y" i e e am e a c i e ia ("O y is que y
esu " e a e e use c icks "su mi " a ew ookma k ame "e ac co y" is a e i o a a ase
igu e . 9 ome age i eg a e i o E 1
igu e 7 A a ookma k o a ca cu a io esu
igu e 7 3 ege e a e ocume wi c i e io Ο 125
7.1.1.2 Revisit the bookmark and get the regenerated result. e ime w e e use e isi s e ookma k e ca se ec e ookma k om e is (i e co e o e wi ow e E wou e ege e a e e esu wi ou aski g e use
o ee e a ame e s igu e 7 3 s ows e ege e a e ocume a e message s ows e ege e a io is success u
7.1.1.3 Revalidate Virtual Documents with Different Criteria. Acco i g o
C a e 3 e e a e ee i e e e e s o e a i a io c i e ia e e equi es e
ege e a e ocume o e e ac y same as e o igi a o e igu e 7 s ows e o igi a i ua ocume igu e 7 3 s ows e ege e a e i ua ocume Com a i g
ese wo ocume s ey wou e ou o e e ac y e same e e 1 a ows e e eme s a ues o c a ge igu e 7 s ows e o igi a i ua ocume igu e 7 5 s ows e ege e a e i ua ocume e e a e some a ues c a ge suc as e e eme "yea " I s o igi a a ue is " " u e cu e a ue is " 5" Acco i g
o e e 1 c i e io i is s i a a i ege e a io e e is e y e i e; i a ows mos e eme s a ues o c a ge A so i a ows e ocume s uc u e o c a ge igu es 7
o 7 7 s ow e o igi a i ua ocume a e ege e a e i ua ocume Ma y e eme s a ues a e c a ge u i s s i a i ege e a io C i e io a ows e
ocume s uc u e o c a ge; i gi es mo e e i i i y a c i e io 1 26
igu e .4 Α ookma k wi c i e io 1
igu e . ege e a e i ua ocume wi c i e io 1 2
igu e .6 A ookma k wi c i e io
igu e 7 7 ege e a e i ua ocume wi c i e io 28
. .2 E ege e a io E a ua io
W e E oes y amic ege e a io E ca s AW o ge e a e e i ua ocume a e E oes e a i a io is sec io e a ua es e ge e a io a e e a i a io
igu e .8 9 ome age
(1 Com a e e E ge e a e i ua ocume s wi e o igi a i ua ocume s ge e a e y e a ica io E i eg a es a ica io s i o e y e me ia sys em a i i e ce s e sou ce ocume s om a ica io s Si ce e o igi a i ua ocume is a s a e i o a we -s uc u e ocume i is im o a a a a om a ica io e e same as e o igi a o e am e e ca cu a io esu s ou e e ac y e same as e o igi a a oug e o ma may e a i e i e e A so use s a e e ec i g o ge a simi a ayou ocume suc as o si e i e wi a ackg ou E a s a es e o igi a ocume i o a M ocume a e ge e a es some s y e i e o is ocume o a e a simi a ayou as e o igi a igu e 7 1 s ows e 9 mo e ome age a as ee i eg a e i o E igu e 7 s ows e o igi a 9 mo e ome age Com a i g e wo igu es ey a e e same
2
e i eg a io oes o a ec e a ica io s ou ook a oug e "su mi e " que y wi go o E ga eway i s a e e i ec e o e es i a io a ica io igu e 7 3 s ows e ege e a e i ua ocume igu e 7 9 s ows e ca cu a io esu a e a ica io Com a i g ese wo ocume s e co e s a e e ac y same owe e e ayou s a e some sma i e e ces ese a e ue o e imi a io s o cu e s y es ee a guages W e a s o mi g e wee i e e s y es ey o o wo k e ec y
E e a ( 6_0 a I e a Geomag e ic ie Mo e a ame e s S
{ esu s o MO E ca cu a io s έ
Υ 2005 ay = ou = Mi = Sec = 20 A = 0 ]a
E = 0 e = 400 0 S = - 0 Y = 00 2= -6 00 έ : „ 4 S a i g ai : Geog a ic i o e Co geamag a a g a a g a o g }} 4 00 2 0 00 4 62 0 6 40 } I e a G ie Com M ( Τ = 6 62 8 0(0 g _ -2 046 ( Τ = 4 6 Χ ςηΤ = 6 2 Y ςηΤ _ - 8 6 2 ςηΤ = 4 6 E e a 0 ie Com Χ ( Τ _ - 6 Υ ςηΤ _ - 2 ς Τ = 2
S a i g oi ma s oπ e GSM Χ-Υ a e a is a ce o 2 e: OG E = 2 2 YGSM = -2 6
A e (ma is a ce i e a mi o e ea geomag e ic ie i e (i : ΧGSM = 2 20 YGSM = -2 GSM = -0 2 = 24 O = 6 0
Geog a ic coo s o e O oi a ia y o ec e o e Ea s su ace: } a _ - 0 o g = 268 6 -
{ Co uga e oi : Geog a ic i o e Co geomag e o g e o g e o g -66 2 244 - 8 0 28 - 6 0 88
I e a Geom ie Com M ( = 2 2 ( eg = 4 8 ( =- 02 2 Χ ( ( = 4 02 6 Υ ( = 6 2 ( =- 02 2 o e ί I e e
igu e . 9 ca cu a io esu
( W e oi g ege e a io e e is a ques io w e e e e-ge e a e ocume is e same as e o igi a e e i g o e y amics o e a ica io sys ems a i ua ocume cou c a ge eque y o a e y e e a i a io ocess gi es use s some i o ma io a ou e com a iso s e wee e ew y ge e a e ocume a e o igi a e ee e e s o e a i a io gi e use s e i i i y o e o m y e me ia u c io a i y o a i ua ocume I e e a i a io is o success u is oes o mea e i ua ocume is w o g I us gi es some wa i g message o e use a e ew y-ge e a e i ua ocume as c a ge acco i g o e use s c i e io I may emi e use a e a a is ou -o - a e a e may ee some c a ges U ike a a i io a ookma k w ic us emem e s e a ess o e ocume i oes o a e a y is o y 130
i o ma io a ou i y oi g is ki o e a i a io i ca e e use o com a e e ege e a e i ua ocume wi e o igi a a emi im o o some c a ges w ic is ea y e e a a i io a ookma k
7 Dynamic Hypermedia Functionality
E o i es ookma k use ec a e comme a use ec a e i k u c io a i ies o
e i ua ocume s Add bookmark u c io a i y is esc i e i Sec io 7 1 Sec io
7 1 esc i es user declared comment a Sec io 7 esc i es manual link.
7.2.1 User Declared Comment
(1 A a Use ec a e Comme
C ea i g a use ec a e comme as o owi g s e s • C ick e "a comme " u o • Se ec some e s om sc ee • S eci y g a u a i y • E i comme co e • E i comme i e • C ick "su mi " u o
igu e 7 1 s ows ow o c ea e a comme om UI
( Comme esu s
A e e use c icks "su mi " u o E s o es comme i o ma io i o a a ase e ime w e e use e isi s e i ua ocume E i s ma ke a c o s i e ocume a e-i e i ies e a c o s acco i g o i e e c i e ia a e i se s a ico a e si e o e e eme s ow i igu e 7 11 I igu e 7 11 e a c o "yea = 5" is e oca e a e-i e i ie a e ege e a io W e e use c icks o e ( ico i o s u a wi ow s ows a is o y e me ia co s uc s suc as comme s a i ks s ow i igu e 7 1 ( e e a e wo comme s a o e i k W e e use c icks o e comme i e i igu e 7 1 e wi ow wi is ay co es o i g comme co e s s ow i igu e 7 13 131
Figure 7.10 C ea e a comme
Figure 7.11 ege e a e i ua ocume wi y e me ia co s uc s a ac e 2
igu e . 2 is o comme s a i ks
igu e . is ayi g e comme co e s 133
(3 E a ua io
igu es 7 11 o 7 13 s ow a a i g a ew use ec a e comme is qui e easy o use s o use e E sys em ca s o e a ge e comme i o ma io om a a ase A so e use i e ace o a comme a is ay comme i o ma io is qui e goo
7 Manual Link
A use se ec s some e s om sc ee e e e s a ame e s i e i k Se ice Me u a su mi s e eques o E E a s a i k i o a a ase e ime e use c icks
e i k i e i e y e me ia co s uc s wi ow o a e se a i k
7 1 Add a Manual Link. C ea i g a ma ua i k as o owi g s e s
• C ick e "a i k" u o ;
• Se ec some e s om sc ee ;
• Se ec es i a io ;
• S eci y g a u a i y;
• E i i k i e;
• C ick "su mi " u o
I e y e is "U " e e e s U i e me u; i e y e is a a c o e se ec s a a c o om e a c o is ; i e y e is a ookma k e se ec s a ookma k
om e ookma k is e a c o s a ookma ks a e ee is e e o e e use makes a i k o em I e a c o o e ookma k oes o e is e e use s ou c ea e i
e o e a i g a i k o i igu e 7 1 s ows ow o c ea e a i k om UI
7 Link Results. igu es 7 1 o 7 1 s ow e i k esu s w ose es i a io is a e e a U igu es 7 17 o 7 19 s ow e i k esu s w ose es i a io is a a c o i si e a i ua ocume igu es 7 o 7 s ow e i k esu s w ose
es i a io is a i ua ocume e e a e ee y es o i k es i a io s a U a 134 anchor, and a virtual document in JHE. An anchor is a selected anchor in a JHE supported virtual document. A virtual document is a JHE supported virtual document that can be generated by JHE integrated applications. Depending on different types of link destination, the link traversal is different. For a link that has a specific URL, clicking on the link will take the user to another Web page. For an anchor, clicking on the link will take the user to the virtual document which JHE regenerates, and the destination anchor is highlighted. For a virtual document, clicking on the link will take the user to the virtual document which requires JHE to do regeneration. Also, for the destination document, hypermedia objects are attached on it.
Figure 7.14 Add a new link whose destination is a URL.
igu e . is o i k i o ma io
igu e . 6 a e se o e i k es i a io U 136
Figure 7.17 A a i k w ose es i a io is a a c o
Figure 7.18 is o i k i o ma io
igu e . Traverse to link destination (to the anchor highlighted in red).
igu e .20 Add a link whose destination is a bookmark. 8
igu e .2 is o i k i o ma io
igu e 7 a e se e i k o a i ua ocume 139
7.2.2.3 Evaluation. igu es 7 1 o 7 s ow a a i g a ew ma ua i k is qui e easy o use s o use e E sys em ca s o e a ge e i k i o ma io om
a a ase A so e use i e ace o a comme a is ay i k i o ma io is qui e goo e e a e ee y es o i k es i a io s w ic i c u e a U a se ec e a c o a a ookma ke i ua ocume is a ows use s o i k o ei e esou ce ou si e
E o esou ce i si e JHE, w ic is qui e e i e oug cu e y E o y su o s ma ua i k i wou e o oo i icu o au oma ica y c ea e ese i ks o a c o s i
i ua ocume s as DHE su o s
7.3 Relocation and Re-identification
is sec io gi es es esu s o e oca io a e-i e i ica io e oca io mea s o
i e oca io o e a c o w e e y e o se o e a c o as c a ge is a so
e a es o a c o g a u a i y ecause it e i es e sco e o e a c o Sec io 7 3 1 gi es es esu s a e a ua io s o e oca io e-i e i ica io is o i e i y w e e
e oca e a c o s a e same as e o e is e e s o e e-i e i ica io c i e ia a
e use wa s o use Sec io 7 3 gi es es esu s o e-i e i ica io a a so oes e a ua io s o e-i e i ica io
7.3.1 Anchor Granularity and Relocation
e e is o i e e e me u o c ea i g a a c o e a c o me u is a o e
Comme Se ice Me u (w e e use a s a comme o e i k Se ice Me u
(w e e use a s a i k e a c o me u a ows use s o s eci y a c o g a u a i y a e-i e i ica io c i e ia e oca io is ase o e a c o oca io a e g a u a i y is sec io iscusses e oca io es esu s a e a ua io s 40
. . . es esu s. e e a e ee y es o a c o g a u a i y g o a oca a s eci ic "G o a " mea s e a c o ca a ea i a y ocume a as e same e eme " oca " mea s e a c o ca a ea i e same e eme a yw e e i a
a icu a ocume "S eci ic" mea s e a c o ca o y a ea a a a icu a oca io i a a icu a ocume
igu e 7 3 s ows ow o c ea e a " oca " a c o o e se ec io " eg ee" i e
ocume e i e " a ue c a ge" w e e use a s a comme o e a c o e
" eg ee" e eme is a su e eme u e e eme "I e a Geom ie " I a ea s wice i is ocume igu e 7 s ows e isi i g e ocume e i e " a ue c a ge" y c icki g o e " a ue c a ge" ookma k Si ce i is a " oca " a c o a " eg ee" e eme s i is ocume a e a ac e wi y e me ia co s uc s y c icki g o e ico s esi es same e eme s use s ca see e same comme co e
igu e 7 5 s ows ow o c ea e a "s eci ic" a c o " o i o a " e
" o i o a " e eme is a su -e eme o e eme "I e a Geom ie " w ic a ea s
wice i is ocume igu e 7 s ows e isi i g e ocume e i e " a ue c a ge" Si ce " o i o a " is a "s eci ic" e eme e a ac e comme o y a ea s a e o igi a oca io o e e eme
igu e 7 7 s ows ow o c ea e a "g o a " a c o "yea " e "yea " e eme o y a ea s o ce i is ocume igu e 7 s ows e isi i g e ocume e i e
" a ue c a ge" e "yea " e eme is a ac e wi a ico igu e 7 9 s ows
e isi i g ocume "e ac co y" e "yea " e eme is a ac e wi a ico Si ce i s a "g o a " a c o i a ea s i a ocume s a a e e same e eme u e o e a c o s " eg ee" a " o i o a " o y a ea s a e ocume " a ue c a ge" 4
ecause ey a e o "g o a " ey s ou o y a ea a e ocume a as same i e i ie w e ey a e c ea e
igu e .2 C ea e a " oca " a c o
igu e .24 e oca e " oca " a c o s 42
igu e .2 Create a "specific" anchor.
igu e .26 Relocate a "specific" anchor. 1 3
igu e 7 7 C ea e a "g o a " a c o
igu e 7 e isi e same ocume 1
igu e 7 9 e isi a o e ocume
7 3 1 E a ua io e a o e es esu s o e a E ca success u y i
e a c o s oca io s e es esu s o e a E gi es use s a i i y o s eci y a c o g a u a i y w ic o i es e i i i y o use s o e am e i a use a s a comme o a a c o a wa s e comme o a ea i a e e a e i ua
ocume s e ca s eci y e g a u a i y as "g o a " e oes o ee o a e a c o
o a e o e i ua ocume s o mu i e imes I a use wa s o a a comme
a o y e a es ο a e y a icu a oca io e e ca s eci y e y e "s eci ic" I e wa s ο a comme o ce wi ou e y i g e same i o ma io o e same e eme a ea s a i e e oca io s e e ca gi e e y e " oca " 4
7 3 e i e i ica io
. .2. es esu s. A e i i g e a c o s oca io E ee s o i e i y
a e e oca e a c o is e same o e as e o igi a y ma ke o e e e a e wo c i e ia o e-i e i ica io e eme s a ue ca c a ge; e eme s a ue ca o c a ge
om igu es 7 3 o 7 9 a e eme s a ues a e a owe o c a ge
igu e 7 3 s ows a a c o s e-i e i ica io c i e ia is " a ue ca o c a ge"
igu e 7 31 s ows e isi i g e ocume Si ce e o igi a a ue is " " e ew a ue is " " ey a e o same E gi es a wa i g message y a i g a i k ico a e si e o e e eme o ose a i e eme s e ico s a ac e a e ue
igu e . 0 A a " o a ue c a ge" a c o 46
igu e . e a i a e a c o s
7 3 E a ua io . e a o e es esu s o e a E ca e-i e i y e-
oca e a c o s success u y E gi es use s a i i y o s eci y a c o e-i e i ica io c i e ia I use s equi e e a c o a ue o e o c a gea e e E com a es e
ew a ue wi e o igi a a ue I ey a e o same E gi es a wa i g message o use s u s i a ac es y e me ia co s uc s o e e eme s is gi es e use
e i i i y o eci e w e e e s ou emo e e ou -o - a e a c o o us ea e i
e e 147
7.4 Comparisons with Other Similar Systems
To supplement applications with hypermedia functionality, a hypermedia engine is needed to model and maintain application-specific hypermedia structures. Hypermedia engines execute independently of an application with minimal modifications to it, and provide the application's users with hypermedia support. Notable projects include
Mic ocosm s U i e sa iewe ( a is 199 eck es (Kacma 1995 e ΟΟ-
a iga o (Ga i o 199 We ise (G Ο ak 1999 S ( a e Som e 1999
InfiniTe (Anderson 2001).
7.4.1 Microcosm
Microcosm is an open hypermedia system developed in University of Southampton which can support generic links and computed links. Microcosm supports viewers with different levels of awareness of the full set of Microcosm protocols. The fully aware viewers are applications adapted at the source code level. These fully aware viewers can participate in the full range of protocols. The semi-aware viewers are applications adapted in some way to participate in some subset of the full communication protocol.
Typically this is achieved using the application's own macro language. Some application programs that one might wish to use offer no access to source code and have no macro programming language. Such applications can be hypermedia-enabled by using the
Universal Viewer which sits on top of unaware program, and handles the communications with Microcosm.
The Microcosm Universal Viewer handles all communications with Microcosm for a list of applications without any modifications for the applications. The Universal
Viewer maintains a list of applications and monitors Microcosm events in order to 148 i e i y w e a og am o is is is au c e W e i i e i ies suc a e e i a ac es a sma Mic ocosm ico o e a ica io s i e a C icki g o is ico
o uces a me u i e ica o e ac io me u o a y o e iewe e U i e sa iewe is a " o y" w ic is es o si e o a commu ica io s wi Mic ocosm a a i g a y commu ica io s a a e ossi e wi e a ica io e a ica io commu ica es wi e U i e sa iewe oug wi ows E ( y amic a a
E c a ge c i oa o a ame swa i e
7 eck es
" eck es" uses a au o omous ocess a is com e e y e e a o e a ica io e
aci i y mo i o s a ica io ac i i y a o i es y e me ia se ices o a ica io s
u i g o a use s is ay
ese a oac es ca mi imi e e i e ac io s e wee e a ica io com o e a y e me ia e gi e us e uci g e e e o mo i ica io ecessa y o
e o i a e is i g a ica io wi y e me ia se ices o i e y ei e gi es is a so a ows ese aci i ies o su o a ica io s a ca o o o o ee o e e e si e y mo i ie o o i e some e e o y e me ia ac i i y
eck es ese s a mo e ase o a ocess mo e o y e me ia a o e
emise a a e y "s a se" se o messages ass e wee e a ica io a
y e me ia com o e s I ca e accom is e wi o mo i ica io o a i ia mo i ica io o e a ica io com o e ; i equi es o mo i ica io o e a ica io s acke o a a s o e 149
The hypermedia facility monitors the activities in windows on the user's workstation. Whenever a window is opened, closed or moved, the hypermedia facility is notified of the event by the window manager. The window manager is an operating system specific process that can monitor window events (such as an XWindow mouse movement or activity). The hypermedia facility must interact with the window manager in order to obtain information about the existence of windows, specifically the title of a window, and the location of each window on the display. The window title serves as the identifier for the window's contents, allowing the hypermedia facility to create and maintain links based on the value of the title string. Links, anchors and navigation requests are maintained by the hypermedia facility. Link markers are determined and displayed by the hypermedia facility. The link destination is delivered to the application through the window manager or a file.
7.4.3 00-Navigator
00-Navigator is an object-oriented implementation of a domain-specific architecture for hypermedia. This framework comprises a set of class hierarchies representing well- known hypertext concepts: nodes, links, access structures and a collaboration model implemented in abstract classes that allows an object-oriented application to be extended with hypertext functionality. 00-Navigator views applications as having three layers: the objects layer, the hypermedia layer and the interface layer. The objects layer contains the application data and behavior, the hypermedia layer implements navigation, and the i e ace aye ese s o es a i ks Α commu ica io mo e is e i e o i e ac between the objects layer with hypermedia layer, and between hypermedia layer with interface layer. The 00-Navigator is implemented in SmallTalk environment. 0
.4.4 We ise
We ise is a o e y e me ia sys em o o i e s uc u es suc as co e s i ks a o a io a gui e ou s s o e i y e me ia a a ases e e a o e We ages
is i c u es e a i i y o use s co a o a i e y o c ea e i ks om a s o M
We ages ey o o ow a su o o c ea i g i ks o a s o We ages wi ou w i i g M a ge ags
e y e me ia s uc u es a e s o e i a y e me ia a a ase e e o e om
e e ise y e me ia amewo k a e se ice is a ai a e o e We ia a o i a y U e We ise sys em is com ose o We ise c ie s a s uc u e se e s A s uc u e se e mai ai s i o ma io a ou y e me ia s uc u es (suc as
o es i ks a gui e ou s
e We ise c ie e a es e e use o ake a a age o o e y e me ia se ices w e wo ki g wi a i a y a ica io s I oes so y ei g a ki o
"mi ewa e" e wee a ious a ica io s u i g o e use s wo ks a io a o e o mo e s uc u e se e s
e commu ica io e wee e We ise c ie a e s uc u e se e s is com ia o e O e y e me ia o oco — a iga io a I e ace (O - a o eac a ica io a is e e e wi o e y e me ia se ices e We ise C ie im eme s a co es o i g a ica io w a e A a ica io w a e a es e commu ica io wi i s co es o i g a ica io is i c u es au c i g e a ica io a eques i g e a ica io o o e a is ay a ocume 151
7.4.5 SFX
S is a ge e ic i k se ice i a y i i a y e i o me a ca ge e a e y amic
i ks S is a i k se ice sys em ui i G e U i e si y i y i i a y e i o me
S o i es y amic a o e i ks o use s; s a ic i ks a e o co si e e
S a ici a es o e ia i ks o use s i ks a e ese e o use s o y u o use
eques o e uce i k ge e a io e ays A S u o is i se e i o eac eco i
e i a y
o eac i k-sou ce a i e i ie is i e e i a S - u o is i e i ie
o s e o owi g i o ma io
• I o e se e om w ic e i k-sou ce o igi a es
• a a ase I o e a a ase w e e e i k-sou ce o igi a es
• u ique eco I o e i k-sou ce wi i a a a ase
• e S se e ocess a is e ecu e y c icki g is u o
A use mus e ici y eques i ks o a i k-sou ce y c icki g e S - u o
C icki g a s e s e i e i ie o e oca a ge a uses i o u e i k-sou ce i o i s e i o me e e ocume is a se i o a ge e ic o ma a esse ia
a ame e s a e e ac e e e se e oes co ce ua e i ica io o o e ia i ks
om e Co i (a co ec io o a ici a e co ce ua i ks I o e o e e i e e a
i ks om ei g ese e o e use e S - ase is i o uce e S - ase
esc i es e e a io s i e wee e co ce ua i ks om e Co i a e a ame e
a ues o i k-sou ces o w ic e co ce ua i ks a e a i Ma c i g a ame e s o a
i k-sou ce wi e S - ase i e s ou i e e a i ks 2
.4.6 I i i e
I i i e is a o e y e me ia sys em a ca s o e a mai ai e a io s i s o so wa e a i ac s I i i e is esig e o e i eg a e wi e e is i g o e y e me ia sys em C ime a (A e so 199 suc a e a io s i s c ea e i I i i e ca e
iewe a a e se o e e o igi a so wa e a i ac s wi a e gi ee s a o i e se o o e y e me ia awa e oo s I i i e im o s e ocume s i o e I i i e e i o me u i g i eg a o s o ge e a e keywo a i e i o ma io I i i e uses is i o ma io o ge e a e a c o s a i ks A c o s a i ks i o ma io a e im o e o e C ime a o e y e me ia sys em o is ay o e o igi a e
ocume
I i i e uses e oi e s a a o s eci y oca io s i ocume s A ma i g mus e is e wee oi e s i I i i e a ocS ecs i a o e y e me ia sys em
a e e o e o igi a ocume e I i i e i eg a o a s a es e ocume s i o
I i i e e o ms a keywo sea c a e e o s e a io s i s as i ks o C ime a sys em e e C ime a sys em iews e a io s i s om I i i e -a y e a io s i s a e su o e y usi g i ks
7 7 Com a iso s
A o e y e me ia e gi e sys em is e y amic y e me ia E gi e ( E E is a
y e me ia sys em a ca o i e y e me ia u c io a i y o a a y ica a ica io s
y i e ce i g ocume s o messages e wee e a ica io s com u a io a a use i e ace e ai s a e esc i e i Sec io 5 153
y e me ia e gi es i e i ow a ica io s i eg a e wi y e me ia
sys ems; w a ki o y e me ia u c io a i y e y e me ia e gi e ca su y a
ow a ica io s commu ica e wi e y e me ia e gi e o e am e Mic ocosm s
U i e sa iewe a es a commu ica io s wi ou mo i ica io o a ica io s
sou ce co es; We ise a E use a ica io w a e s o i eg a e wi y e me ia
sys ems Ea y y e me ia e gi es (Mic ocosm a eck es o y su o i s -
ge e a io y e me ia u c io a i y (suc as i ks a o es ; w i e We ise a
I i i e su o s mo e y e me ia u c io a i y a a e We - ase Ma y y e me ia
e gi es commu ica e wi a ica io s y message assi g usi g e is i g o oco s (e g
We ise uses O ; some use o e a i g sys em s eci ic oo s o a e commu ica io s
(suc as eck es uses wi ow e e ma age
e a o e y e me ia e gi es a e e a ua e y usi g e I y e me ia
amewo k esc i e i C a e 3 a e 7 1 s ows e a ua io s o e is i g y e me ia
e gi es ese y e me ia e gi es a e ma y c a ac e is ics i commo suc as
i eg a io wi iewe s i eg a io wi i o ma io sys ems su o o i e i ie s o
o ec s i e a ocume a essi g a y e me ia u c io a i y o e o em
su o s i ua ocume s e ce E a S E a S ca a a y e e
u e yi g e a io s i s ase o e a ica io i o ma io e a se e sou ce
ocume s a i se i ks o ese ocume s i ks a e y amic a au oma ica y
ge e a e owe e ey o o su o ege e a io e oca io a e-i e i ica io 154
Table 7.1 E a ua io s o y e me ia E gi es
Sys em equi eme s Mic ocosm eck es We ise E - a iga o S I i e I eg a io wi iewe Yes Yes Yes Yes Yes Yes Yes I eg a io wi IS o o o Yes o Yes o i ua oc su o o o o Yes o Yes o ocume ge e a io o o o Yes o o o ocume ege e a io o o o o o o o e oca io Yes o Yes o o o o e i e i ica io Yes o Yes o o o o U ique I s o o ec s Yes Yes Yes Yes Yes Yes Yes I e a ocume Yes Yes Yes Yes Yes Yes Yes a essi g mec a isms A ica io s eci ic o o o Yes o Yes o me a a a y e me ia Yes Yes Yes Yes Yes Yes Yes u c io a i y
7.5 System Extensibility
A o e e am e o ASA s mo e is Τ 9C Τ 9C is simi a o 9 mo e e
i e e ce is a Τ 9C oes o use so a wi as o e o e a ame e s ee e igu e
7 3 s ows e ome age (http://nssdc.gsfc.nasa.gov/space/cgm/t89.html) o Τ 9C mo e igu e 7 33 s ows e Τ 9C ca cu a io esu
A i g a ew mo u e i o is o ec as o owi g s e s (1 A a y e ocume
s uc u e; ( Ma ku ocume ; a (3 A Τ 9C as a ew mo u e o E Ac ua y
a i g a ew a ica io o E oes o equi e oo muc wo k o o Mos com o e s
(Se ec io Ma age UIW ege e a io E gi e Se ice Mo u e a ocume
Ma age o o ee o c a ge A ew ocume a s a o a A ica io W a e
o e ew a ica io ee o e a e is o es E as goo sys em e e si i i y
igu e 7 3 9C mo e que y a e
igu e . 9C ca cu a io esu 6
.6 S a a s Use I E
JHE uses XML, XML Schema, XPointer, XPath and HTML standards. JHE translates the
source documents into XML documents and represents the document structure with XML
Schema. JHE generates XPointer expressions to represent anchor location information
and uses XPath tools to relocate anchors in the documents. JHE uses HTML to display
the source documents and implement some User Interface functions.
7.7 e ec io s o e Im eme a io
Due to the current technologies, there are some limitations of the current JHE system.
(1) Currently the document structure is inferred and created manually by the JHE developer. If JHE can automatically infer the document structure, it will make application integration into JHE more efficient.
(2) Current JDOM tools cannot handle very big and complicated document well. Many existing Web sites generate documents that contain multimedia objects and script functions, which are difficult to parse.
(3) The Document Translator currently is using manually created stylesheet files to form the display Web pages. Due to the limitation of the current stylesheet language, it is difficult to mimic the appearance of the translated documents to be exactly sane as the source documents from the application.
(4) If the element's value is changed, JHE gives users warning messages by inserting a pink icon at the side of the element. Currently JHE does not allow users delete the invalid anchor or comment. It is not difficult to extend for the future system.
JHE does not specify user access rights. Users can view comments from other persons. In the future JHE should have access right control functionality.
JHE does not identify whether a newly created document looks similar to some document that the user has created previously.
The sameness criteria that allows parts of the document's content to change is not implemented due to the complexity of storing and identifying parts of the document structure. However, it should not be very difficult to implement in the future JHE system. CHAPTER 8
CONTRIBUTIONS
This research makes the following contributions:
(1) It gives clear descriptions for differences between virtual and static documents from many aspects. The comparisons provide considerations for designing a JIT hypermedia system framework and developing a JHE system as a conceptual proof of the framework.
(2) It introduces the concept of dynamic hypermedia functionality, which provides traditional hypermedia functionality for dynamically-generated virtual documents. The JHE system implements several forms of dynamic hypermedia functionality: dynamic bookmarks, manual links and user-declared comments. Each works for virtual documents and elements within them that can change between generations.
(3) It introduces the concept of dynamic regeneration of virtual documents, which is a requirement for providing virtual documents with dynamic hypermedia functionality. It discusses the requirements, information needed in a JIT system, and the procedure to do dynamic regeneration. This information serves as guidelines to solve the dynamic regeneration problem and helps the developer to build a practical software implementation. JHE facilitates analytical applications to regenerate documents pointed to by users' bookmarks and links. JHE re- validates the regenerated documents according to the sameness criteria, which gives the user some flexibility to manipulate hypermedia functionality.
(4) It introduces the concept of element relocation and re-identification for virtual documents. It discusses requirements, information needed in a JIT system, and the procedure to do relocation and re-identifying for virtual elements. This information helps the developer to choose appropriate methods to solve the relocation and re-identification problem. SHE relocates and re-identifies previously identified objects within (re)generated virtual documents using the document's structure and based on flexible criteria for revalidation.
(5) It designs a framework for JIT hypermedia systems. The framework explores the challenges in JIT hypermedia systems, analyzes the system requirements and proposes a comprehensive overview. It could help one build and evaluate a JIT hypermedia system.
(6) It designs the JHE system in terms of identifiers, implementation architecture, and information flow. The JHE system provides practical solutions to solve problems encountered in the JIT research area and meets all the requirements of the JIT hypermedia system framework.
157 CHAPTER 9
DISSERTATION BOUNDARIES AND FUTURE WORK
This section presents some boundaries of this dissertation, reviews the deliverables and describes future research.
9.1 Dissertation Boundaries
This research does not deal with: (1) For binary and multimedia formats, addressing into objects has more complex ways than text-only documents, and selections from objects require tighter integration with the viewer. Therefore, JHE will only handle the textual content of documents. (2) In some applets and highly interactive systems, some computation is coded directly into the screen and executed directly on the client viewer.
In these cases, a hypermedia engine may need to be more tightly integrated into the interface computation, in order to parse the contents of displays as they are created on the client. The current JHE will not address this situation. The JHE implementation has many limitations due to current technologies' limitations (see Section 7.7). Several future extensions are also envisioned (see Section 9.3).
9.2 Deliverables
This project has several procedural and technical results. All are well-documented and available free of charge.
• The JHE infrastructure.
• Full documentation for JHE and integrating applications (how to analyze application metadata, how to write application wrappers).
158 159
• The hypermedia services (add bookmarks, comments, links, etc.) JHE created to prove the infrastructure works.
• Java and Javascript source codes to implement JHE modules.
• Documentation for JHE system settings and configurations.
9.3 Potential Future Work
Future work includes:
• Implementing more hypermedia functionality for the JHE system, such as automatic linking and guided tours. Since DHE already supports automatic linking, it is not difficult to add an automatic linking hypermedia service. To build a guided tour, the JHE developer should have a through understanding of the node relationships inside the application. For example, which document is the root, and which documents are the leaves or subsections.
• Integrate more applications to JHE. Adding a new application into JHE requires the JHE developer to analyze the document structure in the application and to build a new Application Wrapper for the application.
• Improving and extending the JIT hypermedia framework. The JIT hypermedia system can support more functionality for users. For example, it can add access permission modules based on user groups.
• Support virtual documents with binary formats. JHE needs a new Selection Manager to get selections from binary objects (such as an image in the Web page) and a different format to express locations in a binary object.
• Investigating more granularities for determining when documents and elements are same. These could include: same "context"; same/related "semantic meaning" from a thesaurus or some concept on the same ontology tree; same document structure/template; same document cluster; from the same application.
• Using different methods to generate unique identifiers instead of the system timestamp in current implementation to make identifiers more intelligent.
• Add more functionality to allow users edit or delete user declared bookmarks, comments or links.
• Improve JHE's implementation by applying more efficient and intelligent tools. REFERENCES
Akscy McC acke a E Yo e 19 "KMS A is i u e y e e o S a i g K ow e ge i O ga i a io s " Communication of ACM. o 31(7 - 35 A a 199 "Au oma ic y e e i k y i g " Proceedings of the 7th ACM Conference on Hypertext: -5 A e so K M M ay o a E W i e ea 199 "C ime a y e e o e e oge eous So wa e E i o me s " Proceedings of the ACM Conference on hypertext: 9 -1 7
A e so K S S e a a W e ie " owa s a ge-sca e I o ma io I eg a io " Proceedings of the 24th International Conference on Software Engineering.
A ews K Ka e a A Mau e 1995 " e y e -G e wo k I o ma io Sys em " Journal of Universal Computer Science. o 1( -
As ma a e y a 1993 " y amic a E e a i e i ki g equi eme s o a ge-Sca e y e me ia Ma ageme Sys ems " Hypertext '93 Workshop on Hyperbase Systems.
ai ey C a W a "A Age - ase A oac o A a i e y e me ia Usi g a i k Se ice " Proceedings on Adaptive Hypermedia and Adaptive Web- Based Systems International Conference: - 3 ai ey C S E - e agy a W a 1 " i k Augme a io A Co e - ase A oac o Su o A a i e y e me ia " 12th ACM Conference on Hypertext and Hypermedia.
ai ey C W a Mi a a Μ Wea " owa s o e A a i e y e me ia " Proceedings of the 2nd International Conference on Adaptive Hypermedia and Adaptive Web-Based Systems.
e e s- ee Cai iau G o a o e ma 199 "Wo Wi e We e I o ma io U i e se " Electronic Networking: Research, Applications and Policy. o (1 5 -5 e e s- ee ie i g a Masi e 199 "U i o m esou ce I e i ie s (U I Ge e ic Sy a " http://www.ietf.org/rfc/rfc2396.txt, e ie e o A i
160 6
aumik A i i Ga a es M aga akis M ai is M ie e O ia Α K is a Q u A a a a a g 1 " owa s y e me ia Su o o a a ase Sys ems " Proceedings of the 34th Hawaii International Conference on System Sciences.
ie e Μ 199 "Au oma i g y e me ia o ecisio Su o " Hypermedia. o ( 3-11
ie e Μ i a i As ma a asu ama ia a Oi as-Kukko e 1997 " ou Ge e a io y e me ia Some Missi g i ks o e Wo Wi e We " Int. J. Human-Computer Studies, World Wide Web Usability Special Issue. o 7(1 31- 5
ake Μ "Im eme a io o e O e U a e S A c i ec u e i e o uc io E i o me o a igi a i a y " http://lib- www.lanl.gov/lww/articles/OpenURL vala.pdf, e ie e o May
o e a M C ig e 1999 " y amic y e e Que yi g a i ki g " ACM Computing Survey. o 31(
usi o sky 199 "A a i e a iga io Su o i E uca io a y e me ia A E a ua io o e ISIS- u o " Journal of Computing and Information Technology. o 7-3
us 19 5 "As We May i k " The Atlantic Monthly. o 17 (1 1 1-1 Ca a a o Μ a A ug iese 1 " A M a M - ase A a i e y e me ia Mo e a i s Im eme a io " Third Workshop on Adaptive Hypertext and Hypermedia, 12th ACM Conference on Hypertext and Hypermedia.
Ca ou e W a a G i 1995 " e is i u e i k Se ice A oo o u is e s Au o s a ea e s " The Web Journal. o 1(1 5 7- 5 Ca A W a a S i c cock 199 " i k Se ices o i k Age s?" Proceedings of Ninth ACM Conference on Hypertext.
Ca A ou e W a a G i 1999 "Im eme i g a O e i k Se ice o e Wo -Wi e We " ACM Computing Surveys. o 31( Ca A S ec o e C Go e a W a 1 "Co ce ua i ki g O o ogy- ase O e y e me ia" Proceedings of Tenth World Wide Web Conference.
Cauma s J. 1999 "A Mo u a amewo k o e C ea io o y amic ocume s " Workshop on Virtual Documents, Hypertext Functionality and the Web at the 8th International World Wide Web Conference. 162
C e a K Syca a 199 "We Ma e A e so a Age o owsi g a Sea c i g " Proceedings of the 2nd International Conference on Autonomous Agents.
Co k i 19 7 " y e e A I o uc io a Su ey " IEEE Computer. o (9 17- 1
Co k i a M egema 19 "gI IS A y e e oo o E o a o y o icy iscussio " ACM TOIS: 1 -15
C a o M a g ei ic M Ma c io i M es e -Ma s a a eag e " a o m o i acy e e e ces o ec 1 (Ρ3 1 S eci ica io " http://www.w3.org/TR/REC20001215, e ie e o Ma c C oss e http://www.crossref.org, e ie e o May 3
Cu i e " ai a i g e s i y e me ia " The New Review of Hypermedia and Multimedia. o 1 19-
a is W a I ea G i a Wi ki s 199 "Mic ocosm a O e y e me ia E i o me o I o ma io I eg a io " University of Southampton CSTR: 9 -15 a is C S K ig a W a 199 " ig y e me ia i k Se ices A S u y o i a y A ica io I eg a io " Proceedings of the 1994 European Conference on Hypermedia Technology.
a is C 1995(1 " o Em e o o o Em e ?" Communications of the ACM (CACM). o 3 ( 1 -1 9
a is C 1995( " a a i eg i y o ems i a o e y e me ia i k se ice " Ph.D. Dissertation, Southampton University.
a is C A ewis a A i k 199 "O A a o osa o a S a a O e y e me ia o oco " 2nd Workshop on Open Hypermedia Systems. http://diana.ecs.soton.ac.uk/ -hcd/protweb.htm, e ie e o A i 3
a is C 1999 " y e e i k I eg i y " ACM Computing Surveys. o 31( e a A Ae s G ou e a Wu "Maki g Ge e a - u ose A a i e y e me ia Wo k " Proceedings of the AACE WebNet Conference: 117- 3 e is e M a M Sc a w 19 " e u e A y e e Sys em o CA A ica io s " Proceedings of ACM SIGMOD'86: 13 -1 6
OI. 199 " e igi a O ec I e i ie Sys em a i s a ica io s i e O i e I o ma io I us y a O e iew o Sou e A ica I o ma io o essio a s " http://www.unisa.ac.za/library2/afdeling/tdienste/doi.html, e ie e o May 3 OM 1 " ocume O ec Mo e " http://www.w3.org/TR/2001/WD-DOM-Level- 3-Core-20010913/DOM3-Core.html, e ie e o A i SSS 199 I e a io a S a a s O ga i a io " ocume S y e Sema ics a S eci ica io a guage ( SSS (ISO 1 179 " Geneva: ISO. 199
u i Co e http://www.dublincore.org, e ie e o u e u ig A 1 "Se a a i g i ks om Co e Usi g M i k a oi e " //www gca ο g/ a e s/ m eu o e 1/ a e s/ /s1 - e ie e o u e 3
E ge a C 19 3 "A Co ce ua amewo k o e Augme a io o Ma s I e ec " Vistas of Information Handling. o 1
e aio o 1 "Sca a e ec o G a ics (S G S eci ica io " //www w3 ο g/ /S G e ie e o u e 3 Ga a es 1 "Augme i g A ica io s wi y e me ia u c io a i y a Me ai o ma io " Ph.D. Dissertation, New Jersey Institute of Technology.
Ga i o A a G ossi 199 "A amewo k o E e i g O ec -O ie e A ica io s wi y e me ia u c io a i y " The New Review of Hypermedia and Multimedia. o1 5- 1
Ga o o Sc wa e a ao i i 1993 " M-Α Mo e ase A oac o y e me ia A ica io esig " ACM Transaction on Information Systems. o 11(1 1-
Cam e a M Goo ma 19 7 " AM A Ge e a - u ose y e e A s ac Mac i e " Proceedings of ACM Hypertext'87 Conference: 1-3 G ?s aek K ou i a S o 1997 " esig i g e e - ase y e me ia se ices o e Wo Wi e We E e ie ces wi Wa e s a s " Proceedings of the ACM Hypertext '97 Conference: 1 7-17 G s εk K a U K Wii 1997 " owa s a e e e ce A c i ec u e o O e y e me ia " Proceedings of ACM Hypertext '97 Conference. G s aek K S o a Q ek 1999 "We ise owse a o y Su o o O e y e me ia S uc u i g Mec a isms o e WWW " Proceedings of the 8th International World Wide Web Conference: 3 - 7 164
G ek K S o a O ou i "O e y e me ia as Use Co o e Me a a a o e We " Proceedings in 9th International World Wide Web Conference.
aa Ka A i ey Coom s a K Mey owi 199 "I IS y e me ia Se ices " Communications of ACM. o 35(1 35-51 a as 19 " e ec io s o o eca s Se e Issues o e e Ge e a io o y e me ia Sys ems " Communication of the ACM. o 31(7 3 - 55
a as a S Maye 199 " e e e y e e Mo e " Communication of ACM. o 37(
y ime "I o ma io ec o ogy - y e me ia/ ime- ase S uc u i g a guage ( y ime " http://www.ornl. gov/sgmUwg8/docs/n 19 / m / i 9 mΙ e ie e o u e 3
Ia e a Sue a e o g 199 " U S asic U Se ice eso u io o e I e e " http://archive.dstc.edu.au/RDU/reports/Apweb96, e ie e o u e 3
Iksa S a S Ga a i 1 " e isi i g a e sio i g i i ua S ecia e o s " Third Workshop on Adaptive Hypertext and Hypermedia, 12th ACM Conference on Hypertext and Hypermedia.
I g am S Caug ey a M i e 199 " i i g e oke - i k o em e W3Ο ec s A oac " Proceedings of Fifth International World Wide Web International Conference.
Kacma C a egge 1991 " o y a ocess-o ie e E e si e y e e A c i ec u e " ACM Transaction on Information Systems. o 9( 399- 19 Kacma C 1995 "A ocess A oac o o i i g y e me ia Se ices o E is i g " Non-hypermedia Applications, Journal of Electronic Publishing: Organization, Dissemination and Design.
Mag io a S a e " i eI o A a i g We E e ie ce y Cus omi a io a A o a io " Proceedings of the First International Conference on Adaptive Hypermedia and Adaptive Web-based Systems.
Ma ic http://manic.cs.umass.edu/^stern/manic.html, e ie e o u y Ma i a Ek u 1999 "A Key o E a ce y e e u c io a i y a i ua ocume s K ow e ge " Workshop on Virtual Documents, Hypertext Functionality and the Web at the 8th International World Wide Web Conference.
May ie 1997 " wo- e e Mo e s o y e e " Intelligent Hypertext: Advanced Techniques for the World Wide Web 13 9 -1 165
McC acke 19 "E e ie ce wi e OG uma -Com u e I e ace Sys em " Int rn t n l rn l f M n M h n St d . o 1 93-31 Mi a E Mo eau C a is a S eic " O M a u ame a O e y e e Mo e o I es iga i g I e o e a i i y e wee y e e omai s " r d n f p rt xt 2000 C nf r n : 93-1 Mi e es ick a Si ge 199 " a i g Se ices a a i g Sys ems (a e ea a e esc i io s e sio 1 1 " http://www.w3.org/TR/REC-PICS- services, e ie e o May 3
e so 19 5 "A i e S uc u e o e Com e e C a gi g a e I e e mi a e " r d n f th ACM t n l C nf r n : -1 O SWG 1997 http://www.csdl.tamu.edu/ohs/, e ie e o May 3
O S http://www.cs.umd.edu/ht02/workshops/openhypermedia.shtml, e ie e o May 3
O e U e O e U S a a " e O e U amewo k o Co e -Se si i e Se ices " http://library.caltech.edu/openurl/PubComDocs/StdDocs/Part 1-PC- 20030513.pdf, e ie e o May 3
Osse ugge a ma a u e ge " y e me ia a e Sema ic We A esea c Age a " rn l f t l Inf r t n. o 3(1
aski 1999 " owa U ique I e i ie " http://www.ieee.org/portal/cms docs/ pubs/proceedings/proc071999.pdf, e ie e o A i 3
ea A 19 9 "Su s i k Se ice A o oco o O e i ki g " r d n of p rt xt 8 : 137-1
a a 1991 p rt xt: r xt t Exp rt xt. McG aw i u is e s a we S a M C am es 1999 "Co ce ua ocume s a y e e ocume s a e wo i e e o ms o i ua ocume " W r h p n rt l nt , p rt xt n t n l t nd th W b t th 8th Int rn t n l W rld W d W b C nf r n .
ao U a M u o 199 " y e e u c io a i y A eo e ica amewo k " Int rn t n l rn l f n C p t r Int r t n.
http://www.w3.org/RDF/, e ie e o u y 3
i k A a Sau e 199 "Mu ica a O e y e me ia Sys em " r d n f EC 2, ACM r : -1 166
ose e g 199 " e S uc u e o y e e Ac i i y " Proceedings of ACM Hypertext '96.
Sc ase egge icks u e y a A Sa c e 199 "O e A c i ec u e o I eg a e y e me ia- ase I o ma io Sys ems " Proceedings of the 26th Annual Hawaii International Conference on System Sciences. o 3 3 -395
SMI //www w3 o g/ / ΕC-smi / e ie e o May 3
S o s a u u a 19 9 " e i- e - ase y e e ocume S uc u e wi owsi g Sema ics " ACM Transactions on Information Systems (TOIS). o 7(1 3- 9
S G //www w3 o g/Τ /S G11/ e ie e o u y 3 is ewai e 1997 "Au oma ic Co s uc io a Ma ageme o a ge O e We s " Information Processing and Management. o 33( 1 1-173
igg a M Weise 19 " E E A e wo k- ase A oac o e a i g " ACM Transactions on Information Systems. o (1 1- 3
U http://www.ietf.org/rfc/rfc2141.txt, e ie e o May 3 a e Som e a oc s e ac 1999 " e e e ce i ki g i a y i i a y E i o me a S a Ge e ic i ki g So u io " D-Lib Magazine. A i 1999 a e Som e a O ei -A ie 1(1 "Ge e a i i g e O e U amewo k eyo e e e ces o Sc o a y Wo ks e iso - u e Mo e " D-Lib Magazine, Ma c 1
a e Som e a O ei -A ie 1( "O e i ki g i e Sc o a y I o ma io E i o me Usi g e O e U amewo k " D-Lib Magazine. Augus 1
a a me e a e -Sc ei e a I o ocks 1 " e e e ce esc i io o e AM +OI " http://www.w3.org/TR/daml+oil-reference, e ie e o Ma c 3
W3C http://www.w3.org/, e ie e o May
Wa e s C a M S e e 1999 " esea c Issues o i ua ocume s " Workshop on Virtual Documents, Hypertext Functionality and the Web at the 8th International World Wide Web Conference.
Wei e S 1995 "Me a a a e ou a io s o esou ce esc i io " http://www.dlib.org/dlib/July95/07weibel.html, e ie e o Augus 167
Wii U K a egge 199 " e y e isco A oac o O e y e me ia Sys ems " Proceedings of the 7th ACM Hypertext Conference: 1 -1
Wi ki so 1999 "Au oma ic i k Ge e a io " ACM Computing Survey. o 31( M " M e E e si e y e e Ma ku a guage " http://www.w3.org/TR/xhtml, e ie e o Ma c 3
i k " M i ki g a guage ( i k " http://www.w3.org/TR/xlink, e ie e o Ma c 3
M " M e e e si e Ma ku a guage " http://www.w3.org/XML/, e ie e o Ma c 3
M -Sc ema " M Sc ema " http://www.w3.org/TR2000/CR-xmlschema-1- 20001024, e ie e o Ma c 3
oi e " M oi e a guage ( oi e " http://www.w3.org/TR/xptr, e ie e o May 3
S " S e e e si e S y e a guage " http://www.w3.org/Style/XSL/, e ie e o May 3
S " S a s o ma io ( S " http://www.w3.org/TR/xslt, e ie e o May 3