Semblog Project
Hideaki Takeda

Ikki Ohmukai

National Institute of Informatics
2-1-2, Hitotsubashi, Chiyoda-ku
Tokyo, Japan

National Institute of Informatics
2-1-2, Hitotsubashi, Chiyoda-ku
Tokyo, Japan

takeda@nii.ac.jp

i2k@nii.ac.jp

ABSTRACT

Semblog Proje t aims to provide personal knowledge publishing tools with Semanti Web te hnlogies, in parti luar,
metadata te hnologies. Semblog tools provide an integrated
environment for gathering, authoring, publishing, and making human relationship seamlessly to enable people to exhange information and knowledge with easy and asual
fashion. We use lightweight metadata format like RSS toa tivate the information ow and its a tivities. We de ne
three level of interest of information gathering and publishing i.e.\ he k",\ lip" and \post" and provide suitable ways
to distribute information a ording to the interest level. We
urrently provide two types of extended ontent aggregator and information retrieval re ommendation appli ations.
We also design new metadata module to de ne personal ontology that realizes semanti relations among people andWeblog sites.

1.

INTRODUCTION

Semblog Proje t aims to provide personal knowledge publishing tools with Semanti Web te hnlogies. Semblog tools
provide an integrated environment for gathering, authoring,
publishing, and making human relationship seamlessly toenable people to ex hange information and knowledge witheasy and asual fashion. We overview our proje t in thispaper.

2.

SIX TYPES OF HUMAN INFORMATIONACTIVITIESWe aim to build systems that support not only human information a tivites, i.e, a tivities in whi h people handle andpro ess information, but also human ommuni ation a tivities, i.e., those in whi h people ex hange information withother people. We show the s heme of human informationand ommuni ation a tivities in Figure ??.
It is an extension of \A tivities and Relationships Table"
proposed by Shneiderman[?℄. The rst layer alled \infor-

mation layer" has three elements that on ern information
handling, i.e. olle t, reate and donate information. Threea tivities form y le, i.e.they are invoked repeatedly. The
se ond layer alled \ ommuni ation layer" has also three elements that on erns ommuni ation handling, i.e. relate,ollaborate and present people. They also form y le. The
two layers are not isolated rather losely related to ea hother. For example, human relationship an ontribute toolle t information, while olle ting information an resultin forming new human relationship. It implies that support
for information a tivities requires support for ommuni ation a tivities, and vi e versa.
Web itself supports only donate (publishing) a tivity. Colle t a tivity is supported by independent servi e, i.e, sear hengines. Create a tivity is also supported independetly likeHTML editors. We an say that web overs informationa tivities but ea h a tivity is supported independently thus
not integrated to ea h other. Furthermore no support fora tivities on the ommuni ation layer.
Weblog is better than web from this viewpoint, be ause Weblog overs more a tivities in an integrated manner. Weblog
dire tly supports authoring and publishing in an integrated
way, sin e Weblog tools usually support both. Furthermore
it ommits ommuni ation a tivities. Ea h weblog an beseen as an identi er of indivisual. We regard a weblog aspersnality of an author or a group of authors. Su h weblog
users tend to refer to ea h other and form so- alled \weblog
ommunities". Weblog tools support su h ommuni ation
like Tra kBa k and ping. But the support is partially, indire tly, and not integrated.
Semblog tools extend weblogs by adding exible but uniform operations for weblog sites and entries like aggregationand lipping, and fa ilities for sear hing and onta ting toother weblog sites. It means that Semblog suite supports
ommuni ation a tivities as well as information a tivities.

3. SEMANTIC WEB AND WEBLOG

In this se tion, we overview the urrent situation of information distribution on Web, Semanti Web and Weblog.
Web la ks fun tionality of information distribution and Semanti Web aims to ful ll the fun tionality by metadata.
We support Semanti Web approa h but it has diÆ ulty of
metadata annotation. So we fo us on Weblog that also use
metadata for information distribution.

Information Layer
Collect

CreateDonateCommunication Layer
Collaborate
RelatePresent

Figure 1: Information and Communi ation A tivities

3.1 Information Processing with Semantic Web
Techniques
We propose ontent distribution support system for individuals with Semanti Web te hniques. Information distribution pro ess does not mean just publishing but an integrated
pro ess ontaining information gathering and authoring. In
the urrent web, however, there is no framework to support
the whole pro ess of information distribution despite the fa tthat Berners-Lee spe i ed the rst world wide web to support both authoring and publishing pro ess equally[?℄. Protrusion of information publishing just a elerates so- alled
information overload.

There is great hope that the Semanti Web te hnologies
will resolve information overload. A ording to the manifesto[?℄, Semanti Web is an environment, whi h onsists of
the ontents with ma hine-readable (semanti ) tags and thesoftware agents, to realize autonomous information distribution and syndi ation. Resour e Des ription Framework(RDF)[?℄ and ontology de nition languages like OWL[?℄
are re ommended by W3C as elemental te hnologies of the
Semanti Web and these are now in pra ti al use.
However it is diÆ ult to produ e ontents with semantitags be ause of their ompli ated syntax and vo abulary.
Ordinary people hardly nd merit of semanti annotation
although it is time- onsuming task. It is also impossible
to annotate the semanti tags to existing enormous information on the Internet. There are some resear hes about
automati annotation with AI te hniques and natural language pro essing[?℄ however their e e ts are still un lear.
In our approa h, we use lightweight metadata formats, i.e.RSS
1.0 (RDF Site Summary[?℄)to a tivate the information ow
and its a tivities. RSS is one of the metadata to des ribe
summary of web site. It ontains general attributes of thesite i.e. title and publisher s name of the web site, andex erpt and updated date of its ontents. Number of web
sites already publish RSS metadata, and several appli ations and servi es alled RSS aggregator are provided basedon this trend.
An aggregator olle ts these RSS from various web sites andreform them to organize this large amount of ontents toshow at glan e. There are two types of aggregator; one isstandalone appli ation that is exe uted on lient PCs. The
other is an aggregation servi e that runs on the internet

server and the user a ess via her/his web browser. The
former appli ations provide rapid browsing of RSS by theirexible user interfa e and the latter enables the user to a ess their information wherever she/he is.
Use of RSS and the aggregator de reases information gathering, but it is just part of information distribution pro ess
as we mentioned. Gathering should be related to information authoring and publishing otherwise it will be anothersear h engines without any sele tion or extra tion.

3.2 Information Creation with Weblog

Weblog is one of the most advan ed systems that use metadata in gathering, reating and publishing.
Re ently weblog has ome into the spotlight in the Web[?℄.
There is no stri t de nition about Weblog but it is re ognized as web site that onsists of mis ellaneous notes updated daily[?℄. In su h sites the authors do not make e orts
to knit up these ontents be ause weblog tools align them inhronologi al order with well-designed HTML format. We
all these frequently posted ontents as small ontents inthis paper. Small ontents in lude various subje ts in luding journal, expertise and ritique. One of most popular
topi s is the introdu tions and omments of the web sites
ranging from news sites to the other small ontents. Some
weblog sites attra t the attention with their own editorial
poli y. The authors of weblog sites reedit the existing web
ontents by quoting them. Moreover there are new typesof Weblogs that riti ize the other weblogs so that theseweblogs are regarded to organize the \weblog ommunity".
Now there are millions of weblog sites in the World. It issurprising number be ause these people are now a tive information reators and distributors as well as information
re eivers thanks to weblog.
Most of weblog sites use so- alled weblog tools that are kindof ontent management systems (CMS)Weblog tools enable
the author to des ribe and edit the small ontents via web
browser and transform the ontents form text format toHTML les. These tools are implemented based on MVC(Model View Controller) model whi h is the fundamental
on ept of web appli ations. The author de nes view template on e then do not have to de orate the ontents withvarious HTML tags. This model de reases the ost of publiation remarkably in omparison with traditional style that
requires lo al text editor and FTP. This feature ontributes
abundant produ tion of the small ontents.
Weblog tools usually generate RSS automati ally. General
attributes su h as publisher s name are set as pro le by theuser. Ex erpt and updated date of ea h ontent are generated by the tools. Most of distributed RSS are generated bythese Weblog tools. Main purpose of RSS aggregator is also
to browse the Weblog site. Currently the number of newssite feeding RSS is expanding.

4. SEMBLOG ARCHITECTURE
4.1 The basic model

We propose personal publishing system using Semanti Web
te hniques and weblog tools. The system supports the whole
pro ess of information distribution whi h in ludes gathering,Application

SearchRecommendation

Aggregation

RSS Aggregator

Management

Blog Tools

Metadata

RSS

Atom

(a) weblog
Application

Egocentric Search

Aggregation

RNA Alliance

RNA / Glucose

Management

Blog Tools

FOAF TrackBack

Metadata

PermaRSS

FOAF

contentsocial relationship(b) Semblog
Figure 2: Four basi

layers for weblog and Semblog

authoring and publishing. Furthermore it onne ts information distribution pro ess of di erent people seamlessly, i.e.,
it supports nding ollaborating and advertising people for
information distribution.

Figure 3: Snapshot of RNA

We divide system ar hite ture into the following four levels,
i.e., metadata format, metadata management, metadata aggregator, and metadata appli ation. In weblog, they orrespond to RSS, Weblog tools, RSS aggregator, and various
appli ations on Weblog respe tively (see Figure ??(a)). In
Semblog, Metadata on person and interpersonal relations
is added in order to in lude a tivities on the ommuni ation levels. We adopt FOAF (Friend-Of-A-Friend) as person
metadata. Content (RSS) and person metadata should be
pro essed seamlessly in every level.
We build our systems by integrating new te hnologies andexisting te hnologies shown in Figure ??(b). A box withthink line indi ates our proposal and a box with thin line
an existing one.
Figure 4: RSS Registration

4.2 RNA: Web-based RSS Aggregator

RNA is a Web-based RSS aggregator written with Perl. A
user an operate RNA through her/his Web server. Figure?? shows a snapshot of RNA.
Firstly the user register URIs of RSS in on guration pageof RNA shown in Figure ??. The user an ategorise these
RSSs. List of sites he ked by the user are onverted into
an RSS that an be read by other RSS-based appli ations
again. RNA an also import and export OPML that is astandard metadata set for Web bookmark.
RNA produ es site/entry list ordered by updated time ofea h element. After getting RSS les from various sour es,
RNA parses these RSSs and merges into single a \global"
RSS tree. RNA onverts this global tree to several forms byordering hronologi ally. These partial trees are published
as RSS and rendered into HTML. Figure ?? shows a site list
with HTML. User an browse des ription element of RSS inea h hannel (site).

RNA supports various output formats su h like HTML, RSS
and other forms i.e., JavaS ript with server/ lient-side XSLT
engines and original template engine. The user an reate
ustomised partial tree using plug-in and template s ript.
The user an save a favourite ontent in RNA to a lip list
with one li k. Clipped ontents are stored in the \ lipped"
RSS tree and it is published like other RSSs. RNA an post
lips to so ial bookmark servi e su h like del.isio.us1 . RNA
extra ts Tra kBa k links from ea h entry in registered sites,and embeds Tra kBa k metadata in RSS and renders it.
The urrent version of RNA ooperates with RSS-basedsear h engine su h as Te hnorati2 and Bulkfeeds3 . By set1
http://del.isio.us/
2
http://www.te hnorati. om/
3

http://bulkfeeds.net/

Figure 5: Site List in HTMLting some keywords, the user an obtain new ontents from
non-registered sites.
Most of RSS generated by Weblog and news sites in ludeategori al information with <d :subje t> vo abulary. RNAan aggregate sele ted ontents by spe ifying ertain ategories, and re-distribute su h ategori al RSS too.
It is ne essary to get RSS and build trees periodi ally sin ethose ontents may hange a ording to update of information sour es. RNA an update periodi ally by ron interfa eof the server. Update interfa e an be alled both manuallyand remotely by XML-RPC message that is generated automati ally by Weblog tools.
RNA he ks syntax of a quired RSS and orre ts them ifthey are not valid. RNA onverts all versions of RSS into
1.0, whi h is based on RDF model.

4.3 Glucose: Stand-alone RSS Aggregator

Glu ose is also an extended RSS aggregator for Windows.
Figure ?? shows a snapshot of Glu ose. Unlike orthodox
aggregators, Glu ose is developed to support information
distribution pro ess in ooperation with oordinating with
RNA. Main fun tions and interfa es of Glu ose are shown
below.
Like in RNA, the user registers URIs of RSS or OPML site
list. Glu ose an a ess several news sites without RSS by"sensor" s ript whi h extra ts arti les and onverts theminto RSS.
Glu ose has three panes interfa e. The left pane shows \RSSChannels" that are subs ribed RSSs by the user. The upper
right pane indi ates the headline list of ontents in luding
title, updated time, sour e and ategory. The lower rightpane is the main pane that shows the ontent of the entry
spe i ed by the headline pane.
Glu ose an extra t Tra kBa k links from ea h ontent. Obtained links are shown below the orresponding entry inheadline pane with "Re:..." like a mailer.
The user an post an entry to her/his Weblog if she/he has

Figure 6: Snapshot of Glu ose

spe i interest for ontent, sin e Glu ose is equiped With
Weblog editor interfa e whi h ommuni ates Weblog tools
with XML-RPC proto ol (Figure ??). The user an also
lip ontents and publish the lip list, sin e Glu ose an
ommuni ate RNA with XML-RPC.

4.4 Suuport for communication activities with
Semblog tools

In our systems, we provide support of information a tivities in the various level. People simply read RSS-based
ontents from various information sour es with our aggregators. These fun tions an make bene t to individual users
in reading and writing Weblog ontents.
As we mentioned earlier, the real value of Semblog is supportof ommuni ation a tivities as well as information a tivities.
Our Semblog system an be used as an information sharing
platform. It is based on simple metadata so that it an beextended easily.

4.4.1 FOAF TrackBack
RNA allian e is a ontent re ommendation system basedon ooperation of multiple RNAs. We use FOAF metadata
to identify ea h RNA. FOAF is an RDF-based metadata
format for des ribing human relationship. Besides the basi
elements su h as name, email and URI of the user, FOAF
provides a statement that user X knows user Y. The urrent
version of RNA an generate FOAF data.
RNA also has an interfa e for FOAF management to extend
so ial network easily. We all this method as "FOAF Tra kBa k". First the user X enters an RNA URI of the user Y
in her/his own FOAF manager. The manager X asks the
manager Y to a quire the FOAF data of Y, and writes "Xknows Y" link in its FOAF. The manager Y re ords "Y
isKnown by X" link in its FOAF and noti es to the user
Y. If the user Y agrees, her/his manager registers "Y knowsX" link. Repeating this pro ess, a personal network of theuser is onstru ted. Following re ommendation methods are
performed in the network.

be ause building and maintaining su h well-organized large
ontology takes a lot of e orts. We aim to develop loose andbottom-up ontology system by ombining personal lassi ation, be ause we onsider that personal knowledge will be
represented with a routine work su h as ategorization andarrangement of information. Figure ?? indi ates a on eptual ar hite ture of the personal ontology system.
At rst we de ne a personal ontology as a hierar hi al system of ategories. Everyone has those ategories, and theyroutinely lassify des ribed and olle ted ontents to the ategory. A label of a ategory an be named arbitrarily byuser. Unlike the onventional ontology, the personal ontology has to be related to the person who produ es it. Therefore we apply FOAF metadata to link between the ontology
and the person.

Figure 7: Weblog Editor

4.4.2 RNA Alliance
RNA Allian e is ollaborative re ommendation based on differen e of registered sites or lips among multiple RNAs. At
rst it al ulates similarities: Si between the user's RNA:R0 and a RNA on the personal network: Ri (1 < i < n).
Ea h RNA has a list of URIs: Ri = fu0 ; : : : ; uk g.

Si=

jR0 \ Ri j
jR0 j + jRi j

The system gives re ommendation s ore: V (u) to ea h URI
by the following formula:

( )=

Vi u

(

Si

0

V

if u 2 Ri
if u 62 Ri (i = 1; : : : ; n)

(u) =

P

( )

n
V u
i=i i
n

This s ore is used for re ommendation to R0 's user if URI
is not in luded in R0 .

u

The system shows the list of re ommended URIs sorted by
the s ore. The user an add these URI to her/his own" he k" list.

4.4.3 Personal Ontology
We propose a bottom-up personal ontology framework using RSS and FOAF metadata. To pro ess small ontents invarious forms, we have to annotate a semanti markup withan ontology language to those ontents. It is diÆ ult to organize pra ti al ontology hierar hy with top-down approa h

Personal ontology metadata onsists of FOAF, RDFS Ontology and Contents RSS. The FOAF des ribes personal information, and the RDFS ontology shows a stru ture of theategories, and the ontents RSS shows written and olle ted
ontents by the user. We add two elements to basi FOAF
model shown in Figure ?? (a). One is <foaf:interest>
whi h is to point the ontents RSS, and the other is <rs:personalontol
that is originally de ned by our Rough Semanti s proje t
4
to indi ate the RDFS ontology. The RDFS ontology is
des ribed with the form of Open Dire tory RDFS format
shown in Figure ?? (b). Ea h node has a fragment ID.
The ontent RSS is similar to a onventional RSS. Our RSS
uses <foaf:topi > to point a ategory on the RDFS ontology, while the onventional model applies <d :subje t> toexpress a thesis of a ontent. This makes our RSS to haveba kward ompatibility. Example of this RSS is shown in
Figure ?? ( ). It should be noted that topi s pointed by thistag are not restri ted to those in their own ontology, rather
any topi s in others' and some global ontology. Separating
ontology and instan es enables su h exible management.
FOAF, RDFS ontology, and RSS are des ribed in separate
les so that we an keep ompatibility with existing appliations on these formats. This is a great bene t that oursystem an ope with su h existing appli ations via theseles.
Our framework enables appli ations and servi es to produ e
new types of sear h or re ommendation. For example, mapping methods between two dire tories or bookmarks are appli able to the personal ontology. Ego entri sear h[?℄ isalso able to realize easily by building a so ial network with
<foaf:knows> in the users' FOAF.
Unlike these peer-to-peer model, we an al ulate a similarity among a personal ontology and the global ontologies su hlike WordNet and ODP in advan e. Multiple personal ontology an be mat hed with ea h other via the global ontology
and this method needs less omputation ost as shown in
Figure ??. In addition, it is not ne essary to modify thatalgorithm in P2P model and personal-global model be ause
both ontology has the same stru ture.
4

http://www.roughsemanti s.org/

Figure 8: Personal Ontology Framework(a) Extended FOAF(b) RDFS Ontology(c) Contents RSS

Figure 9: Personal Ontology Metadata

5.

USE CASE

We applied our system to some ommunities.
One is for an a ademi onferen e alled JSAI2004 (Figure??). Parti ipants registered URI of her/his Weblog to RNA
so that other attendees an browse various opinion for theonferen e and papers. Unlike onventional losed system,
RNA provides that an author of an opinion keeps her/his
authorship permanently.
Other example is edu ation support. Senshu University developed lass support system based on RNA. In this system,
all students and tea hing sta should have Weblog and all
ontents will be aggregated with ea h lass or proje t respe tively. The user post her/his ontent using original editor interfa e whi h ommuni ates multiple Weblog tools andRNA. RNA aggregates and shows re ently updated ontentsof member so that the user an a ess newest topi s in thelass and proje t in the university.
RNA is used as person-based ontents management system.
Resear h institute of e onomy, trade and industry (RIETI)5
publishes Weblog of its resear h asso iates with RNA. OÆial ontents should be managed in single poli y but it may
restri t their ontribution sin e it is so messy to follow. On
the other hand, it does not seem to oÆ ial ontents whenea h member just publishes her/his Weblog freely. Thus
RIETI introdu es RNA to aggregate all ontents from their
Weblog and embed omposite ontents into oÆ ial Web site.
This model may de reases management ost.
We distribute RNA and Glu ose in our web site6 . About
3,000 users downloaded RNA and over 150,000 users downloaded Glu ose from September 2003.
5
http://www.rieti.go.jp/en/index.html
6

http://www.semblog.org/wiki/?en

Figure 11: RNA in an a ademi

Figure 10: Bottom-up Ontology

6.

CONCLUSION

In this paper we propose personal publishing system with Semanti Web te hniques and Weblog tools. We use lightweight
metadata format like RSS to a tivate the information ow
and its a tivities. We de ne three level of interest of information gathering and publishing, i.e., \ he k", \ lip" and\post", and provide suitable ways to distribute information
depending on the interest level.
Through these te hniques and systems, we have shown that
metadata an be used to realize more e erent and more personalized information distribution. Metadata design should
be areful be ause it should be a eptable by many people
and systems. Our approa h, i.e., extending and integrating
RSS and FOAF, is su essful in this aspe t sin e existing
tools like Weblog tools are ready to use them. We hopethat our approa h will be bridge between emerging Semanti Web te hnologies and other growing te hnologies on theInternet.

onferen e[5℄ S. Dill, N. Eiron, D. Gibson, D. Gruhl, R. Guha,
A. Jhingran, T. Kanungo, S. Rajagopalan,
A. Tomkins, J. A. Tomlin, and J. Y. Zien. Semtag andseeker: bootstrapping the semanti web via automatedsemanti annotation. In WWW '03: Pro eedings of thetwelfth international onferen e on World Wide Web,
pages 178{186, New York, NY, USA, 2003. ACM
Press.
[6℄ R. S. S. . S. W. Group. Rdf site summary (rss) 1.0.
http://web.resour e.org/rss/1.0/spe , 2001.
[7℄ F. Manola and E. Miller. RDF Primer. W3C
Re ommendation 10 February 2004.
http://www.w3.org/TR/rdf-primer/.
[8℄ D. L. M Guinness and F. van Harmelen. OWL Web
Ontology Language Overview. W3C Re ommendation
10 February 2004.
http://www.w3.org/TR/owl-features/.
[9℄ K. Numa, I. Ohmukai, M. Hamasaki, and H. Takeda.
Ego entri sear h based on rss. In Poster Pro eedingsof Third International Semanti, 2004.

Web Conferen e(ISWC2004)

7.

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