• 경영과학
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• 제26권1호
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• pp.21-35
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• 2009

There is a controversy on Internet pricing, flat-rate vs. usage-based. This study gives a comparative analysis between flat-rate and two-part tariff which is realistic alternative of usage-based pricing. In a basic economic model, two-part tariff based on ISP's cost structure satisfies allocative efficiency and relatively expand the number of subscribers. But the characteristics of Internet service like consumers' uncertainty on cost, measurement cost of traffic and network externality induce increase of cost or decrease of marginal utility. The analysis shows that small impact of these can make flat-rate more efficient.

• Journal of Computing Science and Engineering
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• 제5권4호
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• pp.338-345
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• 2011

Nowadays mobile devices are used for various applications such as making voice/video calls, browsing the Internet, listening to music etc. The average battery consumption of each of these activities and the length of time a user spends on each one determines the battery lifetime of a mobile device. Previous methods have provided predictions of battery lifetime using a static battery consumption rate that does not consider user characteristics. This paper proposes an approach to predict a mobile device's available battery lifetime based on usage patterns. Because every user has a different pattern of voice calls, data communication, and video call usage, we can use such usage patterns for personalized prediction of battery lifetime. Firstly, we define one or more states that affect battery consumption. Then, we record time-series log data related to battery consumption and the use time of each state. We calculate the average battery consumption rate for each state and determine the usage pattern based on the time-series data. Finally, we predict the available battery time based on the average battery consumption rate for each state and the usage pattern. We also present the experimental trials used to validate our approach in the real world.

• 품질경영학회지
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• 제46권4호
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• pp.797-820
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• 2018

Purpose: It is to seek for an appropriate cost rate analysis methodology of credit card value propositions in Korea. For this issue, it is claimed that methodologies based on probability distribution is more suitable than methodologies based on data-mining. The analysis model constructed for the cost rate estimation is called VCPM model. Methods: The model includes two major variables denoted as S and P. S is monthly credit card usage amount. P stands for the proportion of usage amount at special merchants over the whole monthly usage amount. The distributions assumed for P are positively skewed distributions such as exponential, gamma and lognormal. The major inputs to the model are also derived from S and P, which are E(S) and the aggregate proportion of usage amount at special merchants over the total monthly usage amount. Results: When the credit card's value proposition is general discount, the VCPM model fits well and generates reasonable cost rate(denoted as R). However, it seems that the model does not work well for other types of credit cards. Conclusion: The VCPM model is reliable for calculating cost rate for credit cards with positively skewed distribution of P, which are general discount card. However, another model should be built for cards with other types of distributions of P.

• 인터넷정보학회논문지
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• 제24권2호
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• pp.57-66
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• 2023

현재, 에너지 효율 향상으로 소비감축을 시행하는 새로운 에너지 시스템이 대두되고 있다. 이에 스마트그리드가 확산되면서 계시별 요금제가 확대되고 있다. 계시별 요금제는 계절별 / 시간별로 요금을 다르게 적용해 사용량에 따라 요금을 내는 요금제이다. 본 연구에서는 에너지 전력 사용량 데이터를 예측하기 위해, 온도/요일/시간/계절 등 외부 요인을 고려하고 시계열 예측 모델인 LSTM을 활용한다. 이러한 에너지 사용량 예측 모델을 기반으로 기기별 사용패턴을 분석하여 전력 에너지를 최대부하시간대에서 경부하시간대로 수요이전 함으로써 에너지 사용요금을 절감한다. 기기별 사용패턴을 분석하기 위해서는 시간대별로 기기의 사용량 패턴을 학습 및 분류하는 clustering 기법을 사용한다. 정리하자면, 본 연구에서는 사용자의 전력 데이터 사용량을 기반으로 사용량과 사용 요금을 예측 및 기기별 사용패턴을 분석하고 분석 기반의 맞춤형 수요이전 서비스를 제공함으로써 사용자에게 요금 절감 효과를 가져다 준다.

• Journal of Information Processing Systems
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• 제12권3호
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• pp.436-454
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• 2016

This research presents the battery discharge rate models for the energy consumption of mobile phone batteries based on machine learning by taking into account three usage patterns of the phone: the standby state, video playing, and web browsing. We present the experimental design methodology for collecting data, preprocessing, model construction, and parameter selections. The data is collected based on the HTC One X hardware platform. We considered various setting factors, such as Bluetooth, brightness, 3G, GPS, Wi-Fi, and Sync. The battery levels for each possible state vector were measured, and then we constructed the battery prediction model using different regression functions based on the collected data. The accuracy of the constructed models using the multi-layer perceptron (MLP) and the support vector machine (SVM) were compared using varying kernel functions. Various parameters for MLP and SVM were considered. The measurement of prediction efficiency was done by the mean absolute error (MAE) and the root mean squared error (RMSE). The experiments showed that the MLP with linear regression performs well overall, while the SVM with the polynomial kernel function based on the linear regression gives a low MAE and RMSE. As a result, we were able to demonstrate how to apply the derived model to predict the remaining battery charge.

• 정보관리연구
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• 제38권4호
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• pp.68-87
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• 2007

본 연구의 목적은 국내 대학도서관에서의 전자저널 이용 통계 제공 및 활용 현황을 조사하는 데 있다. 이를 위하여 서울 및 경기 소재 63개 대학교 및 대학도서관을 대상으로 온라인 설문지조사를 시행하였고 이 중 48개 도서관으로부터 응답지를 회수하여 그 결과를 분석하였다. 분석 결과 현재 제공되고 있는 이용 통계 데이터에 대한 만족도는 낮게 나타났으며 특히 비교 가능한 데이터의 부재 문제와 구독 대학도서관 전체의 평균 이용률에 대한 정보가 제공되지 않는 데 따른 불만이 높은 것으로 나타났다. 더불어 선행연구 조사 및 현행 이용 데이터에 대한 분석을 통해 전자저널 평가에 활용할 수 있는 이용 데이터 통계치로서 5가지 유형을 고찰하였다.

• 한국통신학회논문지
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• 제28권11B호
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• pp.1007-1015
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• 2003

In this Paper, we propose a method of determining the price for the elastic traffic in the current or future Internet services. First, we investigate the behavior in the consumption of bandwidth of elastic traffic in IP network. Next, we propose a new method to relate the bandwidth usage with the pricing for the elastic traffic, which is based partially or fully on the usage rate of the network bandwidth. Next, we propose an optimal charging function for elastic traffic, which is applicable to any Internet services. Finally, we will illustrate the implication of the work via simple numerical experiments.

• 한국경영과학회지
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• 제34권1호
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• pp.133-152
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• 2009

This paper analyze the fee structures of digital music contents and the revenue sharing ratios that are now on-going debates in Korean digital contents industry. Especially we consider Korean situation where copyrighters and telecom companies have conflict of interest. We found two major results. First, the choice between the flat rate scheme and the usage-based rate scheme is not important to telecom companies and copyrighters. The important thing is that copyrighters should decide the revenue sharing ratio and given that telecom companies should decide the retail price. Consequently, this way can lead to win-win solutions between them. Second, the flat rate scheme affects the relationship between consumers and telecom companies. Under the flat rate scheme, telecom companies have more benefits than consumers. In the vertical integrated structure, particularly, this tendency is more severe.

• Journal of Information Technology Applications and Management
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• 제30권5호
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• pp.41-57
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• 2023

This paper aims to analyse the factors influencing the implementation of smart factories and their performance after implementation, using the grounded theory analysis method based on interview data. The research subjects were 21 companies that were selected by the Smart Manufacturing Innovation Promotion Group under the SME Technology Information Promotion Agency in 2020-2021 as the best case smart factory implementation companies, and introduced the intermediate stage 1 or above. A total of 87 concepts were generated as a result of the analysis. We were able to classify them into 16 detailed categories, and finally derived six broad categories. These six categories are "motivation for adoption", "adoption context", "adoption level", "technology adoption", "usage effect" and "management effect". As a result of the overall structure analysis, it was found that the adoption level of smart factory is determined by the adoption motivation, the IT technology experience affects the adoption level, the adoption level determines the usage and usage satisfaction, internal and external training affects the usage and usage satisfaction, and the performance or results obtained by the usage and usage are reduced defect rate, improved delivery rate and improved productivity. This study was able to derive detailed variables of environmental factors and technical characteristics that affect the adoption of smart factories, and explore the effects on the usage effects and management effects according to the level of adoption. Through this study, it is possible to suggest the direction of adoption according to the characteristics of SMEs that want to adopt smart factories.

• Environmental Analysis Health and Toxicology
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• 제27권
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• pp.3.1-3.4
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• 2012

Objectives: The current use of humidifier detergent and its harmful impact on humans has arisen as a societal environmental health issue. Therefore, in this study we aimed to explore the relationship between demo-socio characteristics and humidifier use, as well as the monthly usage changes in pregnant women; thus, we report the actual status of humidifier usage of Korea's pregnant population. Methods: From a birth cohort of a Mothers and Children's Environmental Health (MOCEH) study, 1,144 pregnant women who responded through questionnaires including demo-socio characteristics, obstetric status and household environment including whether they use humidifier and frequency of use were included in this study. Statistical analyses were performed to explore the relationship between maternal characteristics and the relevance of the use of humidifiers was performed using a chi-square test, a t-test and univariate logistic regression analysis. The monthly usage rate was demonstrated in the graph. Results: The humidifier usage rate in pregnant women was 28.2%. The average frequency of humidifier usage was 4.6 days per week, 7.3 hours per day. The usage rate was higher in the multipara group and the above the age of 34 age group than in the primipara and below the age of 34 groups. Seoul showed a higher usage rate than Cheonan and Ulsan and as the education level and income increased, the usage rate of humidifiers among pregnant women also increased. In the monthly trend of usage rate, the winter season showed the highest usage rate of over 45% and the lowest in late summer and beginning of fall with a value of 12% or less. Conclusions: During pregnancy, the mother's body is especially vulnerable to hazardous environmental exposure that not only affects the pregnant woman but also the fetus. Further research is still needed to elucidate the route and effect of environmental risk factors. Therefore, based on precautionary and preventive principles, special interest and caution in harmful environments are strongly needed not only at an individual level but also at a national level.