Discovering sequential patterns is an important problem for many applications. Existing algorithms find qualitative sequential patterns in the sense that only items are included in the patterns. ...However, for many applications, such as business and scientific applications, quantitative attributes are often recorded in the data, which are ignored by existing algorithms. Quantity information included in the mined sequential patterns can provide useful insight to the users.
In this paper, we consider the problem of mining sequential patterns with quantities. We demonstrate that naive extensions to existing algorithms for sequential patterns are inefficient, as they may enumerate the search space blindly. To alleviate the situation, we propose hash filtering and quantity sampling techniques that significantly improve the performance of the naive extensions. Experimental results confirm that compared with the naive extensions, these schemes not only improve the execution time substantially but also show better scalability for sequential patterns with quantities.
E-Books on the Mobile E-Reader Kim, Chulyun; Jeong, Ok-Ran; Choi, Jaehyuk ...
Mobile Information Systems,
2013, Letnik:
9, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The market for e-books has been established during the past several years. Many e-book readers are commercially available, and millions of e-book titles are available for purchase or free download. ...E-paper technology has matured enough to be used as the screen for dedicated e-book readers which make reading possible with the familiar feel of reading printed books. In this paper, we provide a comprehensive review of the status of the e-book, including the architecture and features of e-book readers, market adoption and e-book industry ecosystem.
Botnets: threats and responses Jeong, Ok-Ran; Kim, Chulyun; Kim, Won ...
International journal of Web information systems,
01/2011, Letnik:
7, Številka:
1
Journal Article
Recenzirano
Purpose
A botnet is a network of computers on the internet infected with software robots (or bots). There are numerous botnets, and some of them control millions of computers. Cyber criminals use ...botnets to launch spam e‐mails and denial of service attacks; and commit click fraud and data theft. Governments use botnets for political purposes or to wage cyber warfare. The purpose of this paper is to review the botnet threats and the responses to the botnet threats.
Design/methodology/approach
The paper describes how botnets are created and operated. Then, the paper discusses botnets in terms of architecture, attacking behaviors, communication protocols, observable botnet activities, rally mechanisms, and evasion techniques. Finally, the paper reviews state‐of‐the‐art techniques for detecting and counteracting botnets, and also legal responses to botnet threats.
Findings
Botnets have become the platform for many online threats such as spam, denial of service attacks, phishing, data thefts, and online frauds. Security researchers must develop technology to detect and take down botnets, and governments must develop capacity to crack down on botmasters and botnets. Individual computer owners must diligently take measures to keep their computers from becoming members of botnets.
Originality/value
The paper provides a review of current status of botnets and a summary of up‐to‐date responses to botnets in both technical and legal aspects, which can be used as a stepping stone for further research.
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