Young-joo Chung

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In this paper, we study the overall link-based spam structure and its evolution which would be helpful for the development of robust analysis tools and research for Web spamming as a social activity in the cyber space. First, we use strongly connected component (SCC) decomposition to separate many link farms from the largest SCC, so called the core. We show(More)
In this paper, we address the question of how we can identify hosts that will generate links to web spam. Detecting such spam link generators is important because almost all new spam links are created by them. By monitoring spam link generators, we can quickly find emerging web spam that can be used for updating existing spam filters. In order to classify(More)
Rakuten recipe is a recipe site where users can submit their recipes and share with the others. Since recipe contents are generated by users, they usually contain many misspellings, abbreviations, synonyms, hypernyms and hyponyms. Identifying and normalizing these words is essential to retrieve relevant recipes to user's request. In this paper, we introduce(More)
A tunable comb filter based on a fiber loop mirror setup, which incorporates a piece of pumped erbium-ytterbium co-doped polarization maintaining fiber, is newly presented. It is accomplished by controlling the pump power or adjusting a polarization controller in the loop mirror, which results from the fact that the effective birefringence of the(More)
Since current search engines employ link-based ranking algorithms as an important tool to decide a ranking of sites, web spammers are making a significant effort to manipulate the link structure of the Web, so called, link spamming. Link hijacking is an indispensable technique for link spamming to bring ranking scores from normal sites to target spam sites.(More)
We introduce an approach to recommending short-lived dynamic packages for golf booking services. Two challenges are addressed in this work. The first is the short life of the items, which puts the system in a state of a permanent cold start. The second is the uninformative nature of the package attributes, which makes clustering or figuring latent packages(More)
A restoration method for reflection spectra in a serial FBG sensor array with spectral shadowing is proposed and experimentally demonstrated in a WDM/TDM combined multiplexing system. The SNR of each FBG sensor is formulated and analyzed as a function of the number and reflectivities of serial FBG sensors. The maximum number of FBG sensors in a single fiber(More)
Young-joo CHUNG †a) , Masashi TOYODA †b) , Nonmembers, and Masaru KITSUREGAWA †c) , Member SUMMARY In this paper, we propose a method for finding web sites whose links are hijacked by web spammers. A hijacked site is a trustworthy site that points to untrustworthy sites. To detect hijacked sites, we evaluate the trustworthiness of web sites, and examine how(More)
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