• International Journal of Fuzzy Logic and Intelligent Systems
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• v.7 no.4
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• pp.285-294
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• 2007

In this paper, we investigate a novel online estimation algorithm for dynamic Bayesian network(DBN) parameters, given as conditional probabilities. We sequentially update the parameter adjustment rule based on observation data. We apply our algorithm to two well known representations of DBNs: to a first-order Markov Chain(MC) model and to a Hidden Markov Model(HMM). A sliding window allows efficient adaptive computation in real time. We also examine the stochastic convergence and stability of the learning algorithm.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.2
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• pp.83-89
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• 2014

An increasing number of children are now using the Internet. They are starting at a younger age, using a variety of devices and spending more time online. It becomes an important problem to protect the children in online environment. The Internet can be a major channel for their education, creativity and self-expression. However, it also carries a spectrum of risks to which children are more vulnerable than adults. In order to solve these problems, we suggested a binding model of user attributes for enhanced user authentication. We also studied the requirements and prerequisites of a binding model of user attributes. In this paper we described the architecture of binding model of user attributes and showed the effectiveness of the suggested model using simulation. This model can be utilized to enhanced user authentication and service authorization.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.11 no.1
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• pp.67-92
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• 2000

The purpose of this study is to provide possible suggestions in order to promote online transmission service of digital works and the construction of digital libraries. To achieve this purpose, the definition, and characteristics of digital library were reviewed. And the current status of information service of digital libraries in Korea. Japan, and U. S. was examined. The regulations relating to online transmission in digital libraries on the copyright law revised in December 1999 were understood. As a result, this study suggested the establishment of center to manage the reproduction and online transmission of digital works collectively. And it also suggested the introduction of technical measures to protect copyright.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.4
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• pp.2171-2195
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• 2017

When purchasing an online product, a customer tends to be influenced strongly by its reputation, the aggregation of other customers' ratings on it. The reputation, however, is not always trustable since it can be manipulated easily by attackers who intentionally give unfair ratings to their target products. In this paper, we first address identifying trustable users who tend to give fair ratings to products in online rating systems and then propose a method of computing true reputation of a product by aggregating only those trustable users' ratings. In order to identify the trustable users, we list some candidate features that seem related significantly to the trustworthiness of users and verify the robustness of each of the features through extensive experiments. By finding and exploiting these robust features, we are able to identify trustable users and to compute true reputation effectively and efficiently based on fair ratings of those trustable users.

• The Journal of Information Technology
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• v.9 no.3
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• pp.1-14
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• 2006

China has recently (28 August 2004) adopted a new act legalizing the electronic signature. This new act provides electronic signatures with the same legal status as handwritten signatures, and states that on-line certification providers will have to be created in order to ensure the security of on-line operations made using said signatures. This new act is intended to increase Chinese electronic business, and thus to raise the revenue China can expect from said business. And the law grants electronic signatures the same legal effect as handwritten signatures and seals in business transactions, and sets up the market access system for online certification providers to ensure the security of e-commerce. As Internet trade requires a reliable third party to identify the signers, the credibility of online certifying organizations is significant for the transaction security. So, considering the weakness of China's social credibility system, the law regulates that the online signatures certification providers should be approved and administered by governments.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.406-409
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• 2008

Clustering data streams has an importance over many applications like sensor networks. Existing hierarchical methods follow a semi fuzzy clustering that yields duplicate clusters. In order to solve the problems, we propose an extended online divisive agglomerative clustering on data streams. It builds a tree-like top-down hierarchy of clusters that evolves with data streams using geometric time frame for snapshots. It is an enhancement of the Online Divisive Agglomerative Clustering (ODAC) with a pruning strategy to avoid duplicate clusters. Our main features are providing update time and memory space which is independent of the number of examples on data streams. It can be utilized for clustering sensor data and network monitoring as well as web click streams.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1882-1888
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• 2010

It is widely known that ESA(Electric Signature Analysis) method is very useful one for fault diagnosis of an induction motor. Online fault diagnosis system of induction motors using LabVIEW is proposed to detect the fault of broken rotor bars and shorted turns in stator. This system is not model-based system of induction motor but LabVIEW-based fault diagnosis system using FFT spectrum of stator current in faulty motor without estimating of motor parameters. FFT of stator current in faulty induction motor is measured and compared with various reference fault data in data base to diagnose the fault. This paper is focused on to predict and diagnose of the health state of induction motors in steady state. Also, it can be given to motor operator and maintenance team in order to enhance an availability and maintainability of induction motors. Experimental results are demonstrated that the proposed system is very useful to diagnose the fault and to implement the predictive maintenance of induction motors.

• International Commerce and Information Review
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• v.7 no.3
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• pp.231-246
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• 2005

Concerning the regulation of Internet service and the control of electronic commerce in China, It has not specific regulation and various rules or measures to enforce it yet. The common regulatory measures are that online business in some special areas must acquire a license or approval from relative agencies in advance. But whether licensing is an effect regulatory measure still takes time to verify. Accordingly these measures must be unified or coordinated to be enforced effectively. In order to encourage the development of E-Commerce, China will need to focus on developing rules that take advantage of the internet to encourage the economy, and establishing new legal rules or amending the traditional law to create a safe and secure legal environment for online transactions.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.196-198
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• 2016

Online social networking sites such as MySpace, Facebook, Twitter are becoming very preeminent, and the quantities of their users are escalating very quickly. Due to the significant escalation of security vulnerabilities in social networks, user's confidentiality, authenticity, and privacy have been affected too. In this paper, a short study of online social network attacks is presented in order to identify the problems and impact of the attacks on World Wide Web (WWW).

• Journal of Information Technology Applications and Management
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• v.16 no.3
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• pp.17-28
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• 2009

This paper presents a novel method for evaluating the usefulness of online product recommendation. Previous studies on evaluating recommendation systems have mostly relied on two methods : testing the accuracy of estimating user preferences by recommendation systems, or empirically testing the effectiveness with lab experiments involving human participants. The former does not measure the usefulness directly and hence can be misleading; the latter is expensive in that it requires a working online store System and test participants. In order to address the problems, the proposed approach uses simulation to imitate customer behavior and evaluate the usefulness of recommendation. Models for user behavior and an abstract Internet store are developed for simulation. Actual simulation experiments are performed to illustrate the use of the approach.