Personal Knowledge Publishing Suite with Weblog
Ikki Ohmukai

Hideaki Takeda

Kosuke Numa

The Graduate University for
Advanced Studies
2-1-2 Hitotsubashi,
Chiyoda-ku
Tokyo, Japan

National Institute ofInformatics
2-1-2 Hitotsubashi,
Chiyoda-ku
Tokyo, Japan

Yokohama National University79-1 Tokiwadai, Hodogaya-ku
Yokohama, Japan

E-mail: i2k@grad.nii.ac.jp
Abstract
We propose a personal knowledge publishing system called
Semblog that provide an integrated environment for gathering, authoring, publishing, and making human relationship seamlessly. It
enables people to exchange information and knowledge with easy
and casual fashion and with a variety of communication levels,
e.g, three levels of publishing like checking, clipping, and posting.
Semblog extends Weblogs by adding flexible but uniform operations for Weblog sites and entries like aggregation and clipping,and facilities for searching and contacting to other Weblog sites.
These are realized systematically because of intensive metadata
handling.

Categories and Subject Descriptors
H.4.3 [Information Systems]: Communications Applications;
H.3.3 [Information Systems]: Information Search and Retrieval;
I.2.4 [Computing Methodologies]: Knowledge Representation
Formalisms and Methods—lightweight metadata

We propose a personal knowledge publishing system called
Semblog with Semantic Web techniques and Weblog tools.
Semblog suites provide an integrated environment for gathering, authoring, publishing, and making human relationship seamlessly to enable people to exchange information and knowledge
with easy and casual fashion.
We propose two-layered model of information distribution toclarify how we support the process as shown in Fig.1. It is extended form of ”Activities and Relationships Table” by Shneiderman[11].
The first layer has three elements that concern information handling, i.e., collect, create and donate information. However current
web only supports each activities respectively and they are not integrated.
The second layer has also three elements that concerns communication handling, i.e., relate, collaborate and present people.
Organization of information in the first layer are performed by thecommunication process of multiple people in the second layer.
Two layers have different roles but are closely related to eachother. It implies that support for information activities requires
support for communication activities, and vice versa.

General Terms
Metadata management

Keywords
Weblog, Semantic Web, Information Distribution

1.

Introduction

Copyright is held by the author/owner(s).
WWW2004, May 17–22, 2004, New York, NY USA.
ACM xxx.xxx.

Figure 1. Information and Communication Activities

We focus on Weblog because Weblog is an integrated system
for authoring and publishing, while WWW is basically a systemfor publishing. It means that weblog supports activities in the in-formation layer integratedly. The next target is to integrate thecommunication layer and the information layer. Weblog has also
a good feature because weblog users tend to refer to each otherand form so-called ”weblog communities”. But this process is notsupported explicitly by tools.
Semblog suites extend Weblogs by adding flexible but uniform
operations for Weblog sites and entries like aggregation and clipping, and facilities for searching and contacting to other Weblog
sites. It means that Semblog suites support communication activities as well as information activities

by their flexible user interface and the latter enables the user toaccess their information wherever she/he is.
Using RSS and the aggregator, it is probably true that the costof information collection is decreasing, however, finding information set might contain large quantity of noise because of lack of ainformation extraction process. It is also hard to say that the aggregators support whole process of information distribution since
they do not help to create new information.

2. Semantic Web and Weblog

Recently Weblog (blog) or blogging has come into the spotlight in the World Wide Web[4]. There is no strict definition about
Weblog but it is recognized as a web site which consists of miscellaneous notes updated daily[1]. In such sites the authors do
not make efforts to knit up these contents and just align them inchronological order. We call these frequently-posted contents as
small contents in this paper. Small contents include various subjects including journal, expertise and critique. One of most popular topics is the introductions and comments of the web sites ranging from news sites to the other small contents.
Some Weblog sites attract the attention with their own editorial policy. The authors of Weblog sites reedit the existing web
contents by quoting them. Moreover there are new types of Weblogs that criticize the other Weblogs so that these Weblogs are
regarded to organize the ”Weblog community”. Now there are
millions of weblog sites in the World. It is a surprising number
because these people are now active information senders andd distributors as well as information receivers thanks to weblog.
Most of Weblog site uses contents management systems (CMS)
called Weblog tools. Weblog tools enable the author to describeand edit the small contents via a web browser and transform thecontents form text format to HTML files. These tools are implemented based on MVC (Model / View / Controller) model which isthe fundamental concept of web applications. The author defines aview template once then do not have to decorate the contents withvarious HTML tags. This model decreases the cost of publication
remarkably comparing with traditional style which requires local
text editor and FTP. This feature contributes abundant productionof the small contents. Fig.2 shows typical site with Weblog tool.

2.1 Information Processing with Semantic Web
Techniques
We propose a content distribution support system for individuals with Semantic Web techniques. We should consider that the information distribution process does not mean publishing alone but
information gathering as a preprocess. In the current web, however, there is no framework to support the whole process of information propagation despite that TBL specify the first world wide
web to support both authoring and publishing process equally[3].
Now we could not find practical methods to extract appropriate
information from large data source in any other way but searchengines. Since we cannot verify an objective validity of a search
result, it is hard to say that the engines work effectively at any
time.
There is a great hope that the Semantic Web technologies will
resolve information overload. According to the manifesto[2], Semantic Web is an environment, which consists of the contents
with machine-readable (semantic) tags and the software agents,
to realize autonomous information distribution and syndication.
Resource Description Framework (RDF)[14] and other ontology
definition languages[15] are recommended by W3C as elemental
technologies of the Semantic Web and these are now in practicaluse.
However it is difficult to produce contents with semantic tags
because of their complicated syntax and vocabulary. Ordinary
people hardly find a merit of semantic annotation because it is atime-consuming task. It is also impossible to annotate the semantic
tags to existing enormous information on the Internet. There aresome researches about automatic annotation with AI techniques
and natural language processing[6] however their effects are still
unclear.
In our approach, we use a lightweight metadata format that is
RDF Site Summary: RSS[10] to activate the information flow and
its activities. RSS is one of the metadata to describe a summary ofa web site. It contains general attributions i.e. title and publisher’sname of the web site, and excerpt and updated date of its contents.
A number of web sites already publish the RSS, and several applications and services called RSS aggregator are provided based on
this trend.
The aggregator collects these RSS from various web site andreform them to show a large amount of contents at a time. There
are two types of aggregator, one is standalone applications which
are executed on client PCs. The other is aggregation services
that run on the internet server and the user access via her/his web
browser. The former applications provide rapid browsing of RSS

2.2 Information Creation with Weblog

Figure 2. Typical Weblog Site
Weblog tools usually generate RSS automatically. General at-

tributes such as publisher’s name are set by the user as a profile.
Excerpt and updated date of each content are generated by thetools. Most of distributed RSS generated by these Weblog tools.
Main purpose of RSS aggregator is also to browse the Weblog site.
Currently the number of news site feeding RSS is expanding.

semblog applications and conventional Weblog tools. Each module exchanges data in RSS format and communicates with XMLRPC protocol[13] for dynamic invocation. We use Movable Typesystem as Weblog tool[12], which supports RSS and XML-RPC
call.

3. Purpose of Semblog
We propose a personal publishing system with Semantic Web
techniques and Weblog tools. The system will support whole process of information distribution which includes gathering and authoring. Furthermore it connects information distribution processof different people seamlessly.
We define the level of interest of information gathering andpublishing i.e., ”check”, ”clip” and ”post”. Our system provides
different ways to distribute information depend on the interest level.
”Check” means that the user routinely browses particular web
sites and information sources. The user does not know ”what”
is described at those site exactly but she/he know ”what kind” ofcontents included in these sites. We assume that these ”what kind”
knowledge are important for information distribution so that oursystem supports the user to present her/his interest by publishing
the list of URIs she/he always accesses.
”Clip” makes shortcut to a content to which the user have strong
interest among various contents of ”Checked” sites. Our system
automatically publishes the list of ”clipped” contents. We suppose that ”clip” link presents stronger interest of the user than”check” link because it points individual content directly. In addition, contents of ”checked” links are changing momentary but
those of ”clipped” links are persistent (called ”permalink”).
Online bookmark systems were developed for the same objective. These systems make a backup of ”bookmark” or ”favorite”
of the user’s web browser and she/he can obtain the list from anywhere. The user can also make the list to be public or not so thelist will be a web content. However that bookmark is only a static
list of URIs and is lacking functions for change in time. Therefore
these online bookmark systems are not useful for everyone except
the user.
Conventional bookmark systems do not distinguish the URIs
between to a site and a content. It is necessary to switch the way
to distribute these links because they have different level of interest
as described above.
”Post” means that the user quotes content, adds some comment,
and publishes it as a new information. In that case the user presents
not only strong interest but her/his personal opinion. In our system, ”post” type of information publication is made by the Weblog
tools.
Providing different levels for publishing reduces the psychological burden of publishing. In standard BBSs, it is said that lurkers show feeling of belonging to commuities in sprite of their reluctant behavior[5]. This is important to involve ordinary people
into the cycle of information gathering and publishing.
The all process are realized by metadata handling therefore it
is open to other systems and applications. It enables seamless connection of information distribution of different people.

4. Semblog Platform
Fig.3 shows the system architecture of Semblog platform. Semblog system consists of the two types of extended RSS aggregator,

Figure 3. System Architecture

4.1 RNA: RSS Aggregation Service
RNA is an extended RSS aggregator described with Perl CGI.
Fig.4 shows a snapshot of RNA. The user puts this script to her/his
own web server and operates it. Basic function and interface ofRNA are shown below.

Figure 4. RNA: Snapshot• RSS registration and loading
The user should register RSS in a configuration interface.
She/he once enters the URIs of RSS, RNA obtains these

RSS files via HTTP. The user is able to classify each RSS
using categories. The list of registered sites is transformed
into RSS and it can be used by the other applications. RNA
can also import or export an OPML file which is standard
format for the bookmarks.
• Building RSS tree

4.2 Glucose: Standalone RSS Aggregator
Glucose is also an extended RSS aggregator but a standalone
program for Windows. Fig.5 shows a snapshot of Glucose. Different from orthodox aggregator, Glucose is developed to support
information distribution process by coordination with RNA. Mainfunctions and interfaces of Glucose are shown below.

RNA parses multiple RSSs from various sites and builds
a ”global” RSS tree from each RSS tree. The global tree
stores all information obtained by RNA. Next RNA recomposes the global tree into several sub trees according to rule
templates. In default setting, RNA reproduces three typesof sub tree i.e., list of contents sorted by chronological order and updated contents in each site. The user can describe
own template script to generate a new sub tree.
• RSS redistribution
Generated sub trees are distributed as new RSS and are visualized by server / client side XSLT engine using XSLstylesheet. RNA can also transform these RSS into HTMLwith its own template system. With these templates, the user
is easily able to customize an output style rather than XSLTsince the syntax of template is similar to HTML.
• Content clipping
The user can register a content to a clip list in one click.
Clipped contents are stored in ”clipped” RSS tree and it ispublished like the other RSS. Each element of RSS tree ischanging momentary but those of ”clipped” tree are persistent.
• Updating
It is necessary to get RSS and build trees occationally since
its contents are changeable with update of its distributor.
RNA can update periodically by a cron interface of the server.
Update interface can be called both manually and remotely
by XML-RPC message the Weblog tools automatically generated. The latter feature enables the author of a Weblog tonotify her/his new content to RNA.
• TrackBack tracing
RNA queries each registered Weblog tool for that each content has TrackBack links (reverse link provided by Weblog
tools) or not. If exist, RNA extracts these links and adds
them to RSS tree.
• Sanitizing and caching RSS
RNA checks syntax of acquired RSS and corrects them ifthey are not valid. Currently three versions of RSS are proposed i.e., 0.91, 1.0 and 2.0. RNA converts all versions into
1.0, which is based on RDF model. Every RSS is cachedand decomposed to attach to each content as a fine-grained
metadata.
”Antenna” services are already provided to check update ofregistered sites. Conventional antenna obtains HTTP LastModified header of each URI and sorts the site list by chronologicalorder. Using RNA the user can get richer information than theantenna since RSS contains not only updated time but its excerpt
and so on. RNA also enables the user to edit information in thecontents level such as clip and TrackBack tracing.

Figure 5. Glucose: Interface• RSS registration
Like in RNA, the user registers URIs of RSS or OPML site
list. Glucose can access several news sites without RSS by”sensor” script which extracts articles and converts them to
RSS.
• Three-pane interface
Glucose has three pane interface. The left pane shows ”RSS
Channels” which is subscribed by the user. The upper rightpane indicates the headline list of contents including title,
updated time, source and category. The lower right paneshows original contents.
• TrackBack tracing
Glucose can extract TrackBack links from each content. Obtained links are shown below corresponding entry in headline pane like ”Re:” in an emailer.
• Posting to Weblog
With a Weblog editor interface in Glucose, the user can postan entry to her/his Weblog if she/he has strong interest forcontent. This interface uses XML-RPC protocol.
• RNA clipping
The user can post content to the clip list of own RNA using
XML-RPC.
• P2P content recommendation
Glucose runs as a P2P servant and the users automaticallyconstruct P2P network. In this network, several contents

read by someone are distributed randomly and the other user
may receive these contents as a recommendation. The user
can clip or post it to her/his own system and can also register
URI of its RSS to the site list.
We distribute RNA and Glucose in our web site (http://
www.semblog.org/wiki/?en). About 1000 users downloaded
RNA and over 10000 users downloaded Glucose from September
2003.

5.1.2 Categorical Similarity and Recommendation
The user of RNA can categorize the sites and clips she/he registered. Using this category, relationship of interest among users
can be identified and recommended. We apply a recommendation
method based on a categorical similarity to this objective[9].

5.1.3 Relational Filtering

Using functions on Semblog platform, we develop a new typeof recommendation and retrieval systems.

Relational filtering method realizes access control of information using the categorized social network. By merging the personal
network of every user, a large human network like a small world isconstructed. This method extracts multiple communities from thisnetwork and enables information sharing in single community[7].
The user can manage her/his contents which have various level of
disclosure through an unified interface.

5.1 RNA Alliance

5.2 Egocentric Search

Each RNA has XML-RPC interface that can send and receiveits data dynamically. RNA alliance is a content recommendation
system based on cooperation of multiple RNA.
We use Friend Of A Friend: FOAF metadata to identify eachRNA. FOAF is RDF-based metadata format for describing humanrelationship. Besides the basic elements such as name, email and
URI of the user, FOAF provides a statement that user X knowsuser Y.
The current version of RNA can generate FOAF data. RNA
also has an interface for FOAF management to extend social network easily. We call this method as ”FOAF TrackBack”.
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 acquire the
FOAF data of Y, and writes ”X knows Y” link in its FOAF. The
manager Y records ”Y isKnown X” link in its FOAF and notifies
to the user Y. If the user Y agrees, her/his manager registers ”Yknows X” link. Repeating this process, a personal network of theuser is constructed. Following recommendation methods are performed in the network.

Egocentric search provides subjective search which collectsand evaluates collect information for each user[8]. We think that
it is suitable for handling of the small contents like Weblog entries
because connection is usually more subjective than other WWW
pages.
The users daily write and post contents to their Weblog sites
with the editor interface (Fig.8). Egocentric search interface scansa content that the user is posting. If this content contains a hyperlink, the editor acquires whole content and RSS of the link, andconstructs an entry network around the user’s content (Fig.6(left)).
This network indicates not only relations of contents but also human relationships because all entries on Weblog are owned bysome authors. Our method organizes a document network into
person-based network (Fig.6(right)). Each path of the personal
network is weighted relatively to the frequency of citation. Oncethe user cites some site as a topic in the new content (entry), theeditor interface performs egocentric search and shows the result.

5. Application on Semblog Platform

5.1.1 Collaborative Recommendation
Collaborative recommendation is based on difference of registered sites or clips among multiple RNAs. At first it calculates
similarities: Si between the user’s RNA: R0 and each RNA on the
personal network: R1 , . . . , Rn by following formula:Ci
N0 + N i
where Ni is the number of the registered site of Ri , and Ci is thenumber of common site in R0 and Ri . Each RNA has the list of
URIs: Ri = {u0 , . . . , uk }.
The system gives recommendation score: V (u) to each URI
by following formula:
Si =

(
Si
Vi (u) =0

if u ∈ Ri
if u 6∈ Ri (i = 1, . . . , n)Pn

V (u) =

i=i Vi (u)nThis score is used for recommendation to R0 ’s user if URI u is
not included in R0 .
The system shows the list of recommended URIs sorted by thescore. The user can add these URI to her/his own ”check” list.

Figure 6. Document-based(left) and Personbased(right) Network• Relative Chain Search
Relative chain search returns the contents which is directly
linked with the entry cited by the authoring content. Thismodel is based on a simple model but consequently it seems
most trustful. (Fig.7(a))• Co-citation Search
Co-citation search discovers the entries that link the samecontents as the authoring entry links to. Co-citation entries
are retrieved from the RSS cache and the search result contains the weight of authors. (Fig.7(b))

• Keyword Search
Keyword search method picks up the entries by keyword
matching from the RSS cache. Unlike the conventional searchengines, our method targets only related sites around theuser’s Weblog. (Fig.7(c))
The user read search results by these methods and can append
the link of some helpful contents to contents currently describing.
This process may enrich the user’s content and change the search
result of the system.

Figure 8. Snapshot of Proposed Systemseveral way to distribute information depend on the interest level.
Our system called Semblog platform consists of two types of extended content aggregator and information retrieval / recommendation applications. The system will support not only content publishing process but also information gathering and authoring processes synthetically.

7. Additional Authors
Additional authors: Masahiro Hamasaki (The Graduate University for Advanced Studies) and Shin Adachi (Waseda University).

8. REFERENCES

Figure 7. Egocentric Search Methods

6. Conclusion
In this paper we propose a personal publishing system with Semantic Web techniques and Weblog tools. We use a lightweight
metadata format like RSS to activate the information flow and its
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