• 상하수도학회지
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• 제9권2호
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• pp.118-126
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• 1995

The variation of the urban water demand and the amount of water in the distribution reservoir was studied with time for a day. The city of Kwangju in Korea was selected as a study area. The population of Kwangju in the end of 1993 was more than one million and two hundred thousand peoples. The average of daily water use in 1993 was about three hundred and fifty thousand tons a day. One day was devided into 12 divisions with a 2 hour increment. The water use demand related to the amount of water in the distribution reservoir was observed for the given time interval of a day. The water use index was defind in percentage that indicates the ratio of the amount of water use for a time interval to the amount of water use for a day. The water use index with consideration of the water stored in the reservoir was found to be useful to manage and to operate the water supply systems in real time.

• 노동경제논집
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• 제37권2호
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• pp.49-78
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• 2014

본 연구는 2005년부터 도입되기 시작한 주5일 수업제로 인해 나타난 청소년의 시간사용량과 시간배분의 변화를 분석하고, 제도 도입의 효과를 평가하는 데 목적이 있다. 이에 통계청에서 제공하는 2004년과 2009년 "생활시간조사" 자료에 정부의 주5일 수업제 시행으로 나타난 자연실험적 상황을 이용하여 청소년의 시간배분의 인과적 관계를 분석하였다. 분석 결과, 주5일 수업제의 도입으로 증가한 청소년의 재량시간은 대부분 수면과 수동적 여가에 분배되었다. 구체적으로 청소년의 재량시간 1분이 증가할 때 수면시간은 0.46분, 능동적 여가시간은 0.05분, 수동적 여가시간은 0.26분, TV 이용시간은 0.23분 증가하는 반면, 교외 수강 및 자율학습 시간에는 유의미한 영향을 미치지 않은 것으로 나타났다.

• 가족자원경영과 정책
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• 제15권2호
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• pp.129-146
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• 2011

This study is daily life research which aims to explore people's daily lives using a time dairy survey. The purpose of this study is to develop a typology of early, elderly over 55-year-olds using the 2009 Korean Time Use Survey. The results suggest that each man and woman can be classified according to three dimensions which are work time, housework time, and leisure time. Four groups of men are described: the work and leisure balanced type, the work-oriented type, the leisure-oriented type, and the leisure with housework type. Four groups of women are illustrated: the work-oriented type, the leisure-oriented type, the housework-oriented type, and the passive type. The eight groups are characterized by age, education, income, spouse, gender role, lack of time, and satisfaction of time use.

• International Journal of Internet, Broadcasting and Communication
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• 제12권2호
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• pp.77-82
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• 2020

IoT devices frequently require input resources to communicate with various sensors or IoT platforms. IoT device wastes a lot of time as idle time or waiting time to check the data of the input resource and use the input resource. In addition, IoT devices use various input resources. We compares and analyzes input idle time and input waiting time generated from hardware serial input resource, software serial input resource, digital port input resource, and analog port input resource using Arduino widely used as IoT device. In order to design the IoT device framework, it is necessary to understand the characteristics of input resources and to design them to minimize unnecessary input idle time and input waiting time. The analog input wait time has a much larger input wait time than the digital input wait time, so it must be designed to receive analog information periodically at the appropriate timing. The characteristics of the input resources analyzed in this way help to design an efficient IoT device.

• 한국조사연구학회지:조사연구
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• 제12권2호
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• pp.145-157
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• 2011

인터넷 조사에 가중치를 적용하여 그 일반성을 높이고자 하는 시도가 다양하게 이루어졌지만, 안정적으로 적용될 수 있는 방법이 아직까지 개발되지는 않았고 이것이 인터넷 조사의 활용을 제약하고 있다. 인터넷 조사를 위한 가중치 개발에는 준거조사 결과가 필요하지만, 센서스나 정부기관에서 제공되는 통계 중 일부 인구학적 속성을 제외하면 이러한 준거 조사 자료를 구하기 어렵다는 것이 중요 요인이다. 본 연구는 생활시간 조사를 이용해서 가중치를 개발하여 적용할 때, 인터넷 조사의 일반성을 높일 수 있는지를 검토해 보았다. 생활시간 조사는 정부기관에 의해 정기적으로 조사될 뿐만 아니라 센서스와는 달리 라이프스타일에 관련된 다양한 내용을 조사하기 때문이다. 2009년에 실시된 통계청 사회조사의 온라인 버전을 2004년 생활시간 조사결과를 이용해 가중치를 적용한 결과, 2009년에 동일한 설문지를 이용해 실시된 면접원방문 사회조사결과에 보다 일치하는 방향으로 작용하는 것으로 나타났다. 즉 생활시간 조사에서 나타난 취침 시간, 귀가시간, 인터넷 이용시간 등을 이용해서 가중치를 적용했을 때 단지 인구학적 속성만을 이용해서 가중치를 적용하는 경우보다, 온라인 조사결과와 오프라인 조사결과가 보다 근접해지는 경향이 있다는 것이다. 이러한 본 연구의 결과는 생활시간 조사자료가 인터넷 조사의 가중치 개발에 활용될 수 있다는 점을 보여준다.

• 품질경영학회지
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• 제32권3호
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• pp.62-67
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• 2004

This paper presents and compares two block replacement policies under random use durations. The units are put in service altogether and then idle for some time. The time durations during which units are put in service are random variables. Two block replacement policies, called N-policy and T-policy, are presented. Under N-policy, units are replaced altogether after the Nth use. Under T-policy, units are replaced altogether at the end of the use after cumulative use time T elapses. The failures during use durations are replaced by new ones individually. The cost rate expressions under the policies are derived for exponential use durations. Numerical examples are presented to compare the performances of the two policies.

• Human Ecology Research
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• 제55권5호
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• pp.451-463
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• 2017

Recently, increasing one-person households, especially in the young generation, is one of the most important issues reflecting changes in the Korean family and society. The purpose of this study is to examine gender differences in life time use of one-person households aged 25 to 39, comparing with husband-wife couples of the same ages, and to investigate the determinants of subjective time poverty. Data are from the 2014 Life Time Survey by Statistics Korea. The major results are as follows. First, gender differences in time use of single youths were found in home management hours on weekdays. Female one-person householders spent more time in home management than their male counterparts, while male one-person householders spent more time in home management than young husband-wife groups. In addition, a much larger gender difference was found between young husbands and wives. Second, different effects on the subjective time poverty were found in both the groups. Based on these results, the implications for several specialized education and social programs for male and female one-person householders used in the local healthy families support centers are provided.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권7호
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• pp.3112-3127
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• 2018

Since time series clustering is performed without prior information, it is used for exploratory data analysis. In particular, clusters of time series with similar shapes can be used in various fields, such as business, medicine, finance, and communications. However, existing time series clustering algorithms have a problem in that time series with different shapes are included in the clusters. The reason for such a problem is that the existing algorithms do not consider the limitations on the size of the generated clusters, and use a dimension reduction method in which the information loss is large. In this paper, we propose a method to alleviate the disadvantages of existing methods and to find a better quality of cluster containing similarly shaped time series. In the data preprocessing step, we normalize the time series using z-transformation. Then, we use piecewise aggregate approximation (PAA) to reduce the dimension of the time series. In the clustering step, we use density-based spatial clustering of applications with noise (DBSCAN) to create a precluster. We then use a modified K-means algorithm to refine the preclusters containing differently shaped time series into subclusters containing only similarly shaped time series. In our experiments, our method showed better results than the existing method.

• 대한가정학회지
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• 제35권6호
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• pp.173-189
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• 1997

The purpose of this study was to investigate housewives'time use and satisfaction with it and analyze the factors affection these. Subjects were 222 housewives with pre-and elementary school children. The data were analyzed by mean, standard deviation, X-test, t-test, ANOVA and Duncan's multiple range test. The results of this study were as follows : 1) Housewives spent over 1/3 of time on physical care(sleeping.. etc.). 2)The use of time by housewives was mainly influenced by husband's status and children's state(age, the number of extra curricular hours, educational level) 3) The satisfaction with time use was affected by first child's age, husband's age, husband's educational level, wives's educational level, and household income.

• 대한가정학회지
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• 제31권3호
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• pp.101-112
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• 1993

The purpose of this study is to examine the real life of married women employed in a manufacturing industry by analysis patterns of their time use. Data for 172 married working women were gathered from the use of face-to-face interview method. The results were shown as follows; 1) Married female production workers spend 8 hours 44 minutes a weekday, and 10 hours 39 minutes a Sunday on physiological activities, and on socio-cultural activities 1 hour 50 minutes(weekday), 5 hours 30 minutes (sunday). 10 hours 22 minutes, 2 hours 23 minutes were consumed for the employed time compared to 3 hours 4 minutes, 5 hours 28 minutes for household labor. 2) Married working women's employed labor time is excessively too long while for leisure and house work time is too short, which means the patterns of their time use are very unbalanced type.