• Proceedings of the Korea Inteligent Information System Society Conference
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• 2002.05a
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• pp.342-351
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• 2002

A personalized product recommendation is an enabling mechanism to overcome information overload occurred when shopping in an Internet marketplace. Collaborative filtering has been known to be one of the most successful recommendation methods, but its application to e-commerce has exposed well-known limitations such as sparsity and scalability, which would lead to poor recommendations. This paper suggests a personalized recommendation methodology by which we are able to get further effectiveness and quality of recommendations when applied to an Internet shopping mall. The suggested methodology is based on a variety of data mining techniques such as web usage mining, decision tree induction, association rule mining and the product taxonomy. For the evaluation of the methodology, we implement a recommender system using intelligent agent and data warehousing technologies.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.3
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• pp.17-26
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• 2021

Internet of Things is an infrastructure of the interconnected devices. In Internet of Things environment, many smart devices are used in daily life. It requires a new retrieval method using multiple devices. We propose an information retrieval method using both device characteristics and device usage characteristics in multi-device environments. Firstly, information retrieval is performed using a general purpose device. And then, it is performed using dedicated devices. Our method uses both characteristics of the devices and usage characteristics of them. Moreover, it considers queries on the general purpose device. This paper proposes a new retrieval method and describes algorithms. Then, it presents smart home scenarios. Performance evaluation is performed using the scenarios. The evaluation results show higher precision and efficiency than previous researches. The proposed method gets information more accurately and quickly in IOT multiple device environments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1489-1503
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• 2018

Spectrum reuse has attracted much concern of researchers and scientists, however, the dynamic spectrum access is challenging, since an individual secondary user usually just has limited sensing abilities. One key insight is that spectrum usage forecasting among secondary users, this inspiration enables users to obtain more informed spectrum opportunities. Therefore, spectrum usage forecasting is vital to cognitive radio networks (CRNs). With this insight, a spectrum usage forecasting model for the occurrence of primary users prediction is derived in this paper. The proposed model is based on auto regressive enhanced primary user emergence reasoning (AR-PUER), which combines linear prediction and primary user emergence reasoning. Historical samples are selected to train the spectrum usage forecasting model in order to capture the current distinction pattern of primary users. The proposed scheme does not require the knowledge of signal or of noise power. To verify the performance of proposed spectrum usage forecasting model, we apply it to the data during the past two months, and then compare it with some other sensing techniques. The simulation results demonstrate that the spectrum usage forecasting model is effective and generates the most accurate prediction of primary users occasion in several cases.

• Journal of the Korean Data and Information Science Society
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• v.22 no.3
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• pp.437-448
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• 2011

Even though wide usage of internet makes daily life easier, it drives many social problems. This article reveals that heavy usage of internet affects status of mind and relationships with others, and ends up to the internet addiction. We found the more college students use internet, the more they become internet dependent, problematic in relationships with others and internet addictive. And more, internet dependency provokes internet addiction and problems in relationship with others and problems with others induces internet addiction, too.

• Journal of Korean Academy of Nursing
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• v.37 no.5
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• pp.754-761
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• 2007

Purpose: The purpose of this study was to explore factors related to internet game addiction for adolescents. Method: This study was a cross-sectional survey, and data was collected through self-report questionnaires. Data was analyzed using the SPSS program. Results: In logistic regression analysis, the risk of being addicted to internet games was 2.22 times higher in males than females. Adolescents with low and middle academic performance also had a higher risk(2.08 times and 2.54 times) to become addicted to internet games. For the location of the computer, the risk of becoming addicted to internet games were .01 times lower in the living room or brother or sisters' room than in their own room. The risk of becoming addicted to internet games was 1.18 times higher in the higher usage time of internet games. The risk of becoming addicted to internet games was .49 times lower in the more accepting and autonomic parents' rearing attitude and .02 times lower in the high self-efficacy group than the low group. Conclusion: The result of this study suggests that there are noticeable relationships between internet game addiction and gender, academic performance, location of computer, usage time of internet games, parents' rearing attitude, and self efficacy.

• The Journal of Information Systems
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• v.19 no.3
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• pp.35-58
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• 2010

Portal sites have been providing diverse services to attract new users and retain existing customers. Recently, they also added new services and increased quality of the services they provide to secure more customers. It is, however, not clear how people actually react to such activities. We wanted to understand the mechanism associated with users' continued usage intention of current Portal site. We assumed search, e-mail, information, community, e-commerce services as key services provided by most Portal sites and considered valuable by many customers. The quality of these services may directly affect users' continued usage intention. However, we can also assume that attractive alternatives and switching cost may have some influence on users' continued usage intention. Therefore, in this study, key variables pertaining to the quality of key services provided by Portal sites, attractive alternatives, and switching cost were examined to explain the dynamics of users' continued usage intention. An empirical study based on 891 survey responses showed the importance of the quality of key services for users' continued usage intention. Switching cost also demonstrated strong association with users' continued usage intention. However, attractive alternatives did not show a significant association with users' continued usage intention. We also found that the variable attractive alternatives moderated the relationship between the quality of search service and users' continued usage intention and the relationship between the quality of information service and users' continued usage intention. On the other hand, the variable switching cost showed a moderating effect on the relationship between the quality of e-mail service and users' continued usage intention and the relationship between the quality of community service and users' continued usage intention. This study implies that Portal sites need to make efforts not only to improve the quality of key services but also to consider attractiveness of other Portal sites' services and switching cost to secure more customers.

• Journal of Internet Computing and Services
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• v.24 no.2
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• pp.57-66
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• 2023

Currently, a new energy system is emerging that implements consumption reduction by improving energy efficiency. Accordingly, as smart grids spread, the rate system by timing is expanding. The rate system by timing is a rate system that applies different rates by season/hour to pay according to usage. In this study, external factors such as temperature/day/time/season are considered and the time series prediction model, LSTM, is used to predict energy power usage data. Based on this energy usage prediction model, energy usage charges are reduced by analyzing usage patterns for each device and transferring power energy from the maximum load time to the light load time. In order to analyze the usage pattern for each device, a clustering technique is used to learn and classify the usage pattern of the device by time. In summary, this study predicts usage and usage fees based on the user's power data usage, analyzes usage patterns by device, and provides customized demand transfer services based on analysis, resulting in cost reduction for users.

• Survey Research
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• v.12 no.3
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• pp.123-142
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• 2011

This study examines how the family background and educational aspiration of adolescents affect the usage pattern of internet among adolescents. Recently, the focus of studies on digital divides shifts from the gap in the access to the internet to the difference in usage pattern of internet. Building on these studies, this study deals with the concerns that the difference in usage pattern of internet among adolescents potentially lead to the reproduction of social inequality across the generations. The analysis of the Korean Youth Panel Study reveals that the higher educational attainment and higher income level of parents, the children tend to spend more time in searching with the internet and spend less time in doing the internet game. The level of educational aspiration exerts similar effects on internet use of adolescents. The results also show that the effects of educational apsiration is larger among older adolescents. The implications and limitations of this study are discussed.

• Journal of Internet Computing and Services
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• v.6 no.2
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• pp.127-139
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• 2005

This research is in the same line of the research that was carried out in 1999 and 2001, Studies in 1999 and 2001 showed that there are significant differences in the usage levels of Internet in business between countries with longer history of using internet and those with shorter history. The 1999 and 2001 studies also suggested the model on development stages of Internet usage in business, This study is the continuation of the 1999 and 2001 research and used the previous data to compare and analyze the trend of the Internet development stages in leading 100 corporations in Korea, U,S.A., China and Japan in 2002. This study found that there have been significant developments in the ability to use Internet in business in three countries. The differences in Internet usage level in each stage among different countries are compared and analyzed in this study.

• Korean Journal of Health Education and Promotion
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• v.24 no.2
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• pp.15-28
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• 2007

Objectives: In this paper, the survey on internet usage patterns of health consumers was conducted and analyzed in order to determine internet health information assessment criteria for providing correct consumer health information on web-sites. Methods: By using a survey questionnaire with 16 questions on general information and 20 questions on internet health information, data were collected from September 16 to 25, 2005 from 476 participants through an internet web site, http://www.hp.go.kr. Frequency analysis, t-test, and multiple regression were used in order to analyze the difference in assessment criteria, factors influencing assessment criteria, factors influencing user satisfaction, etc. Results: General characteristics of the study population were: the persons over age 40 were the smallest age group; women were accounted for 74.2%; and the persons with average income were the largest income group; and the persons with average health status were the largest health group. Most widely used health information were: exercise, disease, and diet, in order. There was significant difference(p=.001) in importance of assessment criteria between the persons in medical institutions and the persons not in medical institutions. There was no significant difference in other assessment criteria. We also found that contents of websites and easy to use were more important factors than elucidation of information providers and information sources including speciality of information in quality assessment criteria of internet health information. Discussion and Conclusion: Results of this paper were compared with the previous studies from the literatures. Contrary to the previous studies in the literature, there was significant difference in importance of assessment criteria between the persons in medical institutions and the persons not in medical institutions. In order to apply the study results to develop health contents for consumer, there is a need for further upgrade the proposed assessment criteria based on expert opinion.