• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.10 no.1
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• pp.33-39
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• 2011

This paper considers a performance analysis of set-top box (STB) power saving schemes. STB converts the signal into content which is then displayed on the television (TV) screen, and there are typically two operation modes: on mode and stand-by mode. The total energy consumption (TEC), a typical measure of power consumption of STB, is defined by the sum of power consumption in each mode. Recently there are some works of STB power saving schemes that transit STB operation modes efficiently, and the mode transition time point of those schemes can be different. Thus it is required to develop a performance evaluation method that reflects mode transition time points of each scheme to get TEC correctly. This paper proposes a performance evaluation method for STB power consumption using Poisson process to consider the mode transition time point. By modeling STB mode transitions as events of Poisson process, the average time duration of STB mode is computed and accordingly the effect of power saving is evaluated. The performance evaluation result shows that the proposed method achieves 1 to 19% improvement in power consumption compared with a conventional performance evaluation method.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1379-1382
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• 2003

Recently, mobile embedded systems used widly in various applications. Managing power consumption is becoming a matter of primary concern because those systems use limited power supply. As an approach reduce power consumption, voltage can be scaled down. according to the execution time and deadline. By reducing the supplying voltage to 1/N power consumption can be reduced to 1/N. DPM-S is a well known method for dynamic voltage scaling. In this paper, we enhanced DPM-S by using average execution time aggressively. The frequency of processor is calculated based in average execution time instead of worst case execution time. Simulation results show that our method achieve up to 5％ energy savings than DPM-S.

• Journal of the Korean Home Economics Association
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• v.33 no.6
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• pp.73-88
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• 1995

the purpose of this study was to compare the consumption of personal and material resources between working wives and full-time housewives and to conceptualize the cost of working wives by the degree of additional consumption of the resources. The proposed costs of working wives included the long working time (time cost), the short leisure time(energy cost), the increase of expenditures fro services and the serious role conflict(psychological cost). Three methods, t-test, simple regression analysis, multiple regression analysis/tobit analysis were used to analyse the differences in consumption of resources between two groups. On the basis of the analysed results, the employment cost of working wives were discussed.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.6
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• pp.629-636
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• 1988

The reduction of recovery time for delay, in the train movements, is generally realized through train operations in the shortest running time and it leads to maximum energy consumption. At the region of this shortest running time, the amount of energy consumption is sharply reduced according to the running time. So the effect for the energy savings can be largely obtained by furnishing a little spare time on train operations. In this paper, it has been modelized the delay and it's enlargement phenomena and formualted the relief patterns in order to restore the delay by restraint and relief of precedent traints. Also it has been proved the number of relief trains for minimum energy consumption exists and then represented one example of relief patterns.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.9
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• pp.20-27
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• 2014

The power consumption pattern of high-speed railway has rarely during night time. But, during service time, the power is consumed irregularly related to train operation. Especially certain unusual about 1-2 days of service time interval to indicate the power consumption is rapidly growing phenomenon, which causes the capacity of the power contract is the annual electricity bill to rise rapidly as the cause. Normally, amount of peak power consumption bill rate at railway substation is over 20% of total electrical bill. Therefore, high-speed railway substation is expected to be considerably larger savings by reducing the peak power of the default charge(demand power).

• Journal of the Korean Society of School Health
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• v.30 no.3
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• pp.317-324
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• 2017

Purpose: Breakfast is the most important meal to provide energy for the day. Breakfast is especially important to give enough nutritional support to children and adolescents for their physical growth and sexual development. Sleep-related factors like average sleep duration and wake up time would mostly be associated with regular breakfast. This study aimed to investigate the effect of sleep on regular breakfast consumption in Korean adolescents. Methods: The study used the data from the 12th Korea Youth Risk Behavior Web-based Survey (KYRBS-XII) conducted in 2016 by the Korea Centers for Disease Control and Prevention. The data of 62,820 subjects (middle/high school students) were included in the final analysis. The study examined the factors related to regular breakfast, focusing on weekday average sleep duration and wake up time of middle school students and high school students, respectively. Results: Regular breakfast consumption was shown to have a statistically significant association with high economic status, nutritional education, weekday average sleep duration, wake up time, and subjective sleep satisfaction in the multivariate logistic regression. Regardless of the school level, regular breakfast consumption was significantly associated with early wake up time. As to the effect of weekday average sleep duration on regular breakfast consumption, it showed some different results depending on the school level. Conclusion: Regular breakfast consumption of Korean adolescents was related to weekday average sleep duration and wake up time. Having breakfast regularly was affected by both adequate weekday average sleep duration and early wake up time.

• Journal of Family Resource Management and Policy Review
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• v.17 no.2
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• pp.173-194
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• 2013

The purpose of this study was to examine the association between time-income availability and health-promoting behavior (physical practice, smoking, alcohol consumption) of older males (55-69). This study attempted to shed light on health-behavior changes during the transition period of male retirement. The availability of time resources was examined by addressing the amount of weekly paid labor hours. The availability of financial resources was calculated by using the debt-income ratio. The study sample comprised 1,372 (age range 55-69) male respondents of the 2006 Korean Longitudinal Study of Aging (2006 KLOSA wave 1). The results of CHAID (CHi-squared Automatic Interaction Detection) analysis uncovered four distinctive combinations of resource types: time-money poor, time rich, money rich, time-money rich. According to logit results, these four groups had different socio-demographic profiles and different health-behavior risks. The time-money poor males were unlikely to perform physical activities needed to improve their health or to quit smoking or alcohol consumption. This group was also more likely to consume alcohol compared to the time-money resource types. In contrast, the time-money rich group was more likely to exercise longer and more frequently than the reference group (time and money poor). The time-rich types, those who have time-only resources and less money, were likely to be smokers and have problems with alcohol consumption.

• Korean Journal of Human Ecology
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• v.20 no.2
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• pp.377-389
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• 2011

The object of this study was to analyze the meaning of luxurious consumption, the subjects and the objects of luxurious consumption, the desires that propel luxurious consumption, and the luxurious consumption patterns of the past and the present. The materials and information used for this research were acquired by reviewing literatures from a library. The time frame used to separate the past and the present was the Second World War. The analyzed materials and contents for the research were the subjects and the objects of luxurious consumption, the desires that propel luxurious consumption, and the patterns of luxurious consumption. Comparing the trends of luxurious consumption of the past and present historically, the biggest differentiation between the past and present was the spread of subjects and objects of luxurious consumption. In the past, luxury consumption belonged to the wealthy only, but the accessibility of luxury consumption has increased to the point where anybody can buy what they want at will. Another difference was found in the desires that prompt luxury consumption and the consumption patterns of the past and present. Based on these results, several suggestions about luxury consumption were presented in this paper.

• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.3
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• pp.359-366
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• 1993

The purpose of this study was to classify college women according to the general life style, to examine the differences in the characteristics of time consumption, and clothing purchasing behavior, and ultimately to verify the importance of the time variable in life style analysis. 449 subjects were gathered through convenience sampling method and, frequency, precentage, average, $x^2$-test, t-test, ANOVA, Duncan's multiple range test, Factor Analysis, Cluster Analysis were conducted for data analysis. Results of the study were as follows : 1. College women were classified into five subgroups by cluster analysis : fashion-pursuit group, home-intended group, outer-intended group, conservative-economy group, and passive-inactive group. 2. In case of time consumption patterns, significant differences were found according to the different groups in patronage of library and extra off-campus educational programs, participation in household duties, consumption patterns of leisure time and participation in clubs. 3. In case of clothing purchasing behavior, significant differences were found according to the different groups in clothing purchasing motives, information sources, purchasing plan, the number of visited stores, and the confirmation of labels.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.1
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• pp.1-6
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• 2021

In this paper, to expand the use of standalone street lights, an algorithm for controlling LED energy consumption was proposed. The proposed method uses an LED module of a standalone street light divided into n zones. This is a method of reducing total power consumption by preventing the increase in power consumption due to high heat generation by weakly operating the entire LED according to the illuminance. When the amount of sunlight decreases, the whole LED operates weakly and then brightens, and unlike streetlight that act as streetlight, a method of dividing LEDs by area and limiting the number of LEDs operating according to illumination intensity was proposed. This is a way to use a lot of time with limited battery capacity by reducing the generation of heat that consumes the most power in streetlight. It is also a method of continuously changing the initial usage area to improve the total usage time of the LED substrate. As a result of the experiment, it was found that the proposed method extends the service time because it generates less heat than the conventional stand-alone streetlight.