Masashi Toyoda

Associate professor
Kitsuregawa and Toyoda Laboratory
Institute of Industrial Science, University of Tokyo



Web mining, User interfaces, Information visualization, Visual Programming


Publications in English

Publications in Japanese


Information of lectures


Link Spam Structure in the Web

Link spam refers to attempts to promote the ranking of spammers' web sites by deceiving link-based ranking algorithms in search engines. Spammers often create densely connected link structure of sites so called link farm. We studied the overall structure and distribution of link farms in a large-scale graph of the Japanese Web.

Extracting Novel URLs from Web Archives

What's Really New on the Web? Identifying New Pages from a Series of Unstable Web Snapshots (WWW2006 full paper, PDF format).

Identifying and tracking new information on the Web is important in sociology, marketing, and survey research, since new trends might be apparent in the new information. Such changes can be observed by crawling the Web periodically. In practice, however, it is impossible to crawl the entire expanding Web repeatedly. This means that the novelty of a page remains unknown, even if that page did not exist in previous snapshots. We propose a novelty measure for estimating the certainty that a newly crawled page appeared between the previous and current crawls. Using this novelty measure, new pages can be extracted from a series of unstable snapshots for further analysis and mining to identify new trends on the Web.

Evolution of Web Communities

ACM Hypertext 2003 full paper (PDF format)

Web Community Chart

ACM Hypertext 2001 full paper (PDF format)

WWW10 poster paper

WWW10 poster (Power Point)

Finding Related Communities in the Web

WWW9 poster paper

WWW9 poster (Power Point)

HishiMochi (ACM CHI 2000)

A zooming browser for hierarchically clustered documents with incremental keyword search. It provides various zooming and animation effects for finding and browsing scattering target documents.

Hyper Mochi Sheet (ACM CHI 1999)

Hyper Mochi Sheet is a zooming GUI library with multi-focus distortion view (or fisheye view) and animation effect. It allows the user to easily edit hierarchically clustered diagrams such as visual programs and presentations.

KLIEG: A Parallel Visual Programming Environment (IEEE VL 1997, 1998)

KLIEG is a visual parallel programming environment, in which a parallel program is developed by editing visuals (e.g., icons representing processes and lines representing streams) on the screen and will be executed after being translated into KL1 codes. The execution process is animated by the KLIEG tracer. The most significant feature of the KLIEG environment is a support for pattern-oriented parallel programming. Syntactically, a pattern is a process diagram with some unspecified potions. Semantically, a pattern keeps design information, which is useful not only for software engineering purposes but also for visualization of parallel program execution and run-time resource allocations. Basically a pattern is defined by an expert designer and used later by (possibly novice) programmers. The KLIEG provides a neat graphical user interface both for designers and programmers.


SL(1): Ultimate Joke Command

      ====        ________                ___________
  _D _|  |_______/        \__I_I_____===__|_________|
   |(_)---  |   H\________/ |   |        =|___ ___|      _________________ 
   /     |  |   H  |  |     |   |         ||_| |_||     _|                \_____A
  |      |  |   H  |__--------------------| [___] |   =|                        |
  | ________|___H__/__|_____/[][]~\_______|       |   -|                        |
  |/ |   |-----------I_____I [][] []  D   |=======|____|________________________|_
__/ =| o |=-~~\  /~~\  /~~\  /~~\ ____Y___________|__|__________________________|_
 |/-=|___||    ||    ||    ||    |_____/~\___/          |_D__D__D_|  |_D__D__D_|
  \_/      \__/  \__/  \__/  \__/      \_/               \_/   \_/    \_/   \_/

SL (Steam Locomotive) runs across your terminal when you type "sl" as you meant to type "ls". It's just a joke command, and not usefull at all. Put the binary to /usr/local/bin.

Source code(