• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.4
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• pp.61-75
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• 2007

In ubiquitous computing, shared environments are required to adapt to people intelligently. Based on information about user preferences, the shared environments should be adjusted so that all users in a group are satisfied as possible. Although many group recommender systems have been proposed to obtain this purpose, they only consider average and misery. However, a broad range of philosophical approaches suggest that high inequality reduces social agreeability, and consequently causes users' dissatisfactions. In this paper, we propose social welfare functions, which consider inequalities in users' preferences, as alternative aggregation functions to achieve a social agreeability. Using an example in a previous work[7], we demonstrate the effectiveness of proposed welfare functions as socially agreeable aggregate functions in group recommender systems.

• The Journal of Information Technology and Database
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• v.7 no.1
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• pp.42-53
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• 2000

The major goal of this research is to develop an optimal route search algorithm for an intelligent route guidance system, one sub-area of ITS. ITS stands for intelligent Transportation System. ITS offers a fundamental solution to various issues concerning transportation and it will eventually help comfortable and swift moves of drivers by receiving and transmitting information on humans, roads and automobiles. Genetic algorithm, and fuzzy logic are utilized in order to implement the proposed algorithm. Using genetic algorithm, the proposed algorithm searches shortest routes in terms of travel time in consideration of stochastic traffic volume, diverse turn constraints, etc. Then using fuzzy logic, it selects driver-preference optimal route among the candidate routes searched by GA, taking into account various driver's preferences such as difficulty degree of driving and surrounding scenery of road, etc. In order to evaluate this algorithm, a virtual road-traffic network DB with various road attributes is simulated, where the suggested algorithm promptly produces the best route for a driver with reference to his or her preferences.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.1042-1045
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• 2014

Recently several recommender systems have been developed in a variety of applications, but providing accurate recommendations that match the preferences and constraints of various users is quite challenging. This paper presents a method of recommending digital products based on the past preference of a user on the price, rating and selling volume of a product. Experimental results of the method with actual data of Amazon showed that the average accuracy of the recommendations made by the method is 85%. Although the results are preliminary, the method is potentially capable of making more accurate personalized recommendations than existing methods.

• Journal of the Korean Society for Library and Information Science
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• v.32 no.2
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• pp.259-276
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• 1998

This study is to contribute to develop adaptive information systems meeting inside information needs as well as represented information needs, and dealing with every levels of users and user's preferences. Also, this study is to present a method of developing adaptive information system through developing user profile using machine teaming and decision tree, applying relevance feedback using merged vector, and applying user feedback.

• ETRI Journal
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• v.29 no.2
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• pp.169-178
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• 2007

With the advent of ubiquitous computing environments, it has become increasingly important for applications to take full advantage of contextual information, such as the user's location, to offer greater services to the user without any explicit requests. In this paper, we propose context-aware active services based on context-aware middleware for URC systems (CAMUS). The CAMUS is a middleware that provides context-aware applications with a development and execution methodology. Accordingly, the applications based on CAMUS respond in a timely fashion to contextual information. This paper presents the system architecture of CAMUS and illustrates the content recommendation and control service agents with the properties, operations, and tasks for context-aware active services. To evaluate CAMUS, we apply the proposed active services to a TV application domain. We implement and experiment with a TV content recommendation service agent, a control service agent, and TV tasks based on CAMUS. The implemented content recommendation service agent divides the user's preferences into common and specific models to apply other recommendations and applications easily, including the TV content recommendations.

• Journal of the Korea Society of Computer and Information
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• v.23 no.8
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• pp.45-50
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• 2018

Many of the current successful commercial recommender systems utilize collaborative filtering techniques. This technique recommends products to the active user based on product preference history of the neighbor users. Those users with similar preferences to the active user are typically named his/her neighbors. Hence, finding neighbors is critical to performance of the system. Although much effort for developing similarity measures has been devoted in the literature, there leaves a lot to be improved, especially in the aspect of handling subjectivity or vagueness in user preference ratings. This paper addresses this problem and presents a novel similarity measure using fuzzy logic for selecting neighbors. Experimental studies are conducted to reveal that the proposed measure achieved significant performance improvement.

• Journal of Information Technology Applications and Management
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• v.12 no.4
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• pp.45-57
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• 2005

In order to provide personalized knowledge recommendation services, most web portals for organizational knowledge management use category or keyword information that portal users explicitly express interests in. However, it is usually difficult to collect correct preference data for all users with this approach, and, moreover, users' preferences may easily change over time, which results In outdated user profiles and impaired recommendation qualify. In order to address this problem, this paper suggests knowledge recommendation methods for portals using user profiles that are automatically constructed from users' activities such as posting or uploading of articles and documents. The result of our experiment shows that the Proposed method can provide equivalent performance with the manual category or keyword selection method.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.701-702
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• 2008

A large amount of efforts are required to search user's preferred contents for the program contents being provided by IPTV services. In this paper, using collaborative filtering, an automatic recommendation method of IPTV program contents is presented by reasoning similar group preferences on IPTV program contents which constitutes personalized IPTV environments. The proposed method models the user's preference of IPTV program contents with the program attributes such as content, genres, channels actor/actress, staffs and calculates it using the watching history of program contents in different genres and watching times. Also, the proposed method considers timely changing user's preference and the preference oon the content itself, which improves the traditional collaborative filtering methods that can not recommend the non-consumed items.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.151-153
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• 2017

In recommendation system, collaborative filtering is the most important algorithm. Collaborative filtering is a method of making automatic predictions about the interests of a user by collecting preferences or taste information from many users. In this paper five algorithms were used. Metrics such as Recall-Precision, FPR-TPR,RMSE, MSE, MAE were calculated. From the result of the experiment, the user-based collaborative filtering was the best approach to recommend movies to users.

• Journal of Information Technology Services
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• v.9 no.2
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• pp.21-42
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• 2010

As digital convergence and mobile services evolve, personalization becomes one of the most important factors attracting customers. Personalization means functions offering individually customized services with relevant contents using information on individual preferences. This sort of personalized services has attracted great attention of a large part of online firms. One of representative services of such personalized services is a mobile widget service. In this study, we identified seven antecedents affecting the quality of personalized mobile widget services and empirically investigated which antecedent has a significant effect of the quality of personalized mobile widget services. In addition we carried out empirical investigation into the effect of the quality of personalized mobile widget service on user satisfaction and trust. As a result of this research, we revealed that seven variables including information services affected components of personalized services, and usefulness and perceived benefit as components of personalized services affected user trust and satisfaction for personalized services.