• Journal of KIISE:Software and Applications
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• v.29 no.1_2
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• pp.53-64
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• 2002

Association rule discovery is a method that detects associative relationships between items or attributes in transactions. It is one of the most widely studied problems in data mining because it offers useful insight into the types of dependencies that exist in a data set. However, most studies on association rule discovery have the drawback that they can not discover association rules among user groups that have common characteristics. To solve this problem, we segment the set of users into user-subgroups by using feature selection and the user segmentation, thus local association rules in user-subgroup can be discovered. To evaluate that the local association rules are more appropriated than the global association rules in each user-subgroup, derived local association rules are compared with global association rules in terms of several evaluation measures.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.2 no.3
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• pp.204-209
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• 2002

The interest of data mining in artificial intelligence with fuzzy logic has been increased. Data mining is a process of extracting desirable knowledge and interesting pattern ken large data set. Because of expansion of WWW, web data is more and more huge. Besides mining web contents and web structures, another important task for web mining is web usage mining which mines web log data to discover user access pattern. The goal of web usage mining in this paper is to find interesting user pattern in the web with user feedback. It is very important to find user's characteristic fer e-business environment. In Customer Relationship Management, recommending product and sending e-mail to user by extracted users characteristics are needed. Using our method, we extract user profile from the result of web usage mining. In this research, we concentrate on finding association rules and verify validity of them. The proposed procedure can integrate fuzzy set concept and association rule. Fuzzy association rule uses given server log file and performs several preprocessing tasks. Extracted transaction files are used to find rules by fuzzy web usage mining. To verify the validity of user's feedback, the web log data from our laboratory web server.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4703-4723
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• 2018

In recent years, dense small cell network has been deployed to address the challenge that has resulted from the unprecendented growth of mobile data traffic and users. It has proven to be a cost efficeient solution to offload traffic from macro-cells. Software defined heterogeneous wireless network can decouple the control plane from the data plane. The control signal goes through the macro-cell while the data traffic can be offloaded by small cells. In this paper, we propose a framework for cell virtualization and user association in order to satisfy versatile requirements of multiple tenants. In the proposed framework, we propose an interference graph partioning based virtual-cell association and customized physical-cell association for multi-homed users in a software defined small cell network. The proposed user association scheme includes 3 steps: initialization, virtual-cell association and physical-cell association. Simulation results show that the proposed virtual-cell association outperforms the other schemes. For physical-cell association, the results on resource utilization and user fairness are examined for mobile users and infrastructure providers.

• Journal of KIISE:Software and Applications
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• v.35 no.8
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• pp.522-528
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• 2008

Topic map typically provide information to user through the selection of topics, that is using only topic, association, occurrence on the first topicmap which is made by domain expert without regard to individual interests or context, for the purpose of supplementation for the weakness which is providing personalized topic map information, personalization has been studied for supporting user preference through preseting of customize, filtering, scope, etc in topic map. Nevertheless, personalization in current topicmap is not enough to user so far. In this paper, we propose a design of PTRS(personalized topicmap ranking system) & algorithm, using both user profile(click through data) and basic element of topic map(topic, association) on knowledge layer in specific domain topicmap, therefore User has strong point that is improvement of personal facilities to user through representation of ranked topicmap information in consideration of user preference using PTRS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.709-730
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• 2017

To address the challenge of unprecedented growth in mobile data traffic, ultra-dense network deployment is a cost efficient solution to offload the traffic over some small cells. The overlapped coverage areas of small cells create more than one candidate access points for one mobile user. Signal strength based user association in IEEE 802.11 results in a significantly unbalanced load distribution among access points. However, the effective bandwidth demand of each user actually differs vastly due to their different preferences for mobile applications. In this paper, we formulate a set of non-linear integer programming models for joint user association control and user demand guarantee problem. In this model, we are trying to maximize the system capacity and guarantee the effective bandwidth demand for each user by soft-association control with a software defined network controller. With the fact of NP-hard complexity of non-linear integer programming solver, we propose a Kernighan Lin Algorithm based graph-partitioning method for a large-scale network. Finally, we evaluated the performance of the proposed algorithm for the edge users with heterogeneous bandwidth demands and mobility scenarios. Simulation results show that the proposed adaptive soft-association control can achieve a better performance than the other two and improves the individual quality of user experience with a little price on system throughput.

• Journal of the Korea Society of Computer and Information
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• v.24 no.1
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• pp.145-149
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• 2019

Various supplementary authentication methods are used to supplement user authentication and authorization provided by existing password verification online1. In recent years, authentication and authorization methods using user attribute information have been studied and utilized in various services. User attribute information can be divided into static information and dynamic information. The existing methods focus on research to identify users using dynamic information or to generate challenge questions for user reauthentication. Static information such as a user's home address, school, company, etc. is associated with dynamic information such as location information. We propose a method to verify user attribute information by using the association between two attribute information. For this purpose, the static information of the user is verified by using the user's location record which is dynamic information. The experiment of this paper collects the dynamic information of the actual user and extracts the static information to verify the user attributes. And we implemented the user attribute information authentication system using the proposal verification method and evaluated the utility based on applicability, convenience, and security.

• The Journal of the Korea Contents Association
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• v.9 no.4
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• pp.95-102
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• 2009

Recently, remote user authentication scheme protecting user anonymity using smart card has been researched with interest increasing on user privacy. Although authentication scheme providing user anonymity using smart card had been proposed by Das et al, Chien et al. pointed out Das et al. scheme fail to provide user anonymity and proposed new scheme to overcome the problem. A remote system Kim et al. proposed a scheme which is traceable about malicious user with protecting user anonymity. In this paper, we point out that Kim et a1. scheme fail to provide user anonymity and propose a scheme for some problems Kim et al. scheme has. And then we analysis our scheme on cryptophic security and efficiency with Kim scheme.

• Journal of the Korean Association of Geographic Information Studies
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• v.1 no.1
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• pp.70-85
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• 1998

This study intends to identify the effects of user attitude, user education & training on the information systems implementation performance. In order to obtain data, survey questionnaires were distributed to the users of 'D' company, the major findings can be summarized as follows. First, it's suggested from the analyses that user attitude and user education & training independently have statistically significant effects on information systems implementation performance. Second, it's revealed that even though the interaction effects by both user attitude and user education & training have positive effects on the level of usage, but have no statistically significant effects on satisfaction level. Based on these results, it's recommended to convert user attitude favorably toward user environment and to increase the level of user education & training, in order to promote information systems implementation performance. Especially, differentiated user education & training are highly recommended.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.6
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• pp.63-76
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• 2014

Recently the desired information has been recommended to many people in a number of ways using the smartphone. Though there are many applications for that purpose, but most applications does not consider the user's current situation. In order to automatically recommend the information considering the user's situation, it is necessary to predict the future behavior of the user from the records of the past behavior of the user. Therefore, in this paper, we propose a method that predicts the user's future behavior through association analysis based on the user's current behavior which is identified by applying the user's current situation data collected via a smartphone to the Bayesian network built from the user's life log. From the experiments and analysis for five students and five virtual workers, the usefulness of the proposed method is confirmed.

• Journal of The Korean Association of Information Education
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• v.8 no.4
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• pp.547-554
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• 2004

Education is the largest application area of adaptive hypermedia systems. The user modeling is considered a very important part of the field of adpative hypermedia systems. In this paper we present the developed user model which provides different educational contents using a neural network. The user model has been verified on hypermedia for learning about basic web concepts, multimedia and HTML. This paper reports the results of simulation. Our simulation shows that the user model exactly can provide contextual different links for different students.